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class="vector-toc-numb">2</span> <span>Notation</span> </div> </a> <ul id="toc-Notation-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Radioactive,_primordial,_and_stable_isotopes" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Radioactive,_primordial,_and_stable_isotopes"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Radioactive, primordial, and stable isotopes</span> </div> </a> <ul id="toc-Radioactive,_primordial,_and_stable_isotopes-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-History" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#History"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>History</span> </div> </a> <button aria-controls="toc-History-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle History subsection</span> </button> <ul id="toc-History-sublist" class="vector-toc-list"> <li id="toc-Radioactive_isotopes" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Radioactive_isotopes"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.1</span> <span>Radioactive isotopes</span> </div> </a> <ul id="toc-Radioactive_isotopes-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Stable_isotopes" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Stable_isotopes"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.2</span> <span>Stable isotopes</span> </div> </a> <ul id="toc-Stable_isotopes-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Neutrons" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Neutrons"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.3</span> <span>Neutrons</span> </div> </a> <ul id="toc-Neutrons-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Variation_in_properties_between_isotopes" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Variation_in_properties_between_isotopes"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>Variation in properties between isotopes</span> </div> </a> <button aria-controls="toc-Variation_in_properties_between_isotopes-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Variation in properties between isotopes subsection</span> </button> <ul id="toc-Variation_in_properties_between_isotopes-sublist" class="vector-toc-list"> <li id="toc-Chemical_and_molecular_properties" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Chemical_and_molecular_properties"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.1</span> <span>Chemical and molecular properties</span> </div> </a> <ul id="toc-Chemical_and_molecular_properties-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Nuclear_properties_and_stability" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Nuclear_properties_and_stability"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.2</span> <span>Nuclear properties and stability</span> </div> </a> <ul id="toc-Nuclear_properties_and_stability-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Numbers_of_isotopes_per_element" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Numbers_of_isotopes_per_element"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.3</span> <span>Numbers of isotopes per element</span> </div> </a> <ul id="toc-Numbers_of_isotopes_per_element-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Even_and_odd_nucleon_numbers" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Even_and_odd_nucleon_numbers"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.4</span> <span>Even and odd nucleon numbers</span> </div> </a> <ul id="toc-Even_and_odd_nucleon_numbers-sublist" class="vector-toc-list"> <li id="toc-Even_atomic_number" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Even_atomic_number"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.4.1</span> <span>Even atomic number</span> </div> </a> <ul id="toc-Even_atomic_number-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Odd_atomic_number" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Odd_atomic_number"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.4.2</span> <span>Odd atomic number</span> </div> </a> <ul id="toc-Odd_atomic_number-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Odd_neutron_number" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Odd_neutron_number"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.4.3</span> <span>Odd neutron number</span> </div> </a> <ul id="toc-Odd_neutron_number-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> </ul> </li> <li id="toc-Occurrence_in_nature" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Occurrence_in_nature"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>Occurrence in nature</span> </div> </a> <ul id="toc-Occurrence_in_nature-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Atomic_mass_of_isotopes" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Atomic_mass_of_isotopes"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>Atomic mass of isotopes</span> </div> </a> <ul id="toc-Atomic_mass_of_isotopes-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Applications_of_isotopes" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Applications_of_isotopes"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>Applications of isotopes</span> </div> </a> <button aria-controls="toc-Applications_of_isotopes-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Applications of isotopes subsection</span> </button> <ul id="toc-Applications_of_isotopes-sublist" class="vector-toc-list"> <li id="toc-Purification_of_isotopes" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Purification_of_isotopes"> <div class="vector-toc-text"> <span class="vector-toc-numb">8.1</span> <span>Purification of isotopes</span> </div> </a> <ul id="toc-Purification_of_isotopes-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Use_of_chemical_and_biological_properties" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Use_of_chemical_and_biological_properties"> <div class="vector-toc-text"> <span class="vector-toc-numb">8.2</span> <span>Use of chemical and biological properties</span> </div> </a> <ul id="toc-Use_of_chemical_and_biological_properties-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Use_of_nuclear_properties" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Use_of_nuclear_properties"> <div class="vector-toc-text"> <span class="vector-toc-numb">8.3</span> <span>Use of nuclear properties</span> </div> </a> <ul id="toc-Use_of_nuclear_properties-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-See_also" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#See_also"> <div class="vector-toc-text"> <span class="vector-toc-numb">9</span> <span>See also</span> </div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#References"> <div class="vector-toc-text"> <span class="vector-toc-numb">10</span> <span>References</span> </div> </a> <ul id="toc-References-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">11</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-titlebar-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">Isotope</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Go to an article in another language. Available in 119 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-119" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">119 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-af mw-list-item"><a href="https://af.wikipedia.org/wiki/Isotoop" title="Isotoop – Afrikaans" lang="af" hreflang="af" data-title="Isotoop" data-language-autonym="Afrikaans" data-language-local-name="Afrikaans" class="interlanguage-link-target"><span>Afrikaans</span></a></li><li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D9%86%D8%B8%D9%8A%D8%B1_(%D9%83%D9%8A%D9%85%D9%8A%D8%A7%D8%A1)" title="نظير (كيمياء) – Arabic" lang="ar" hreflang="ar" data-title="نظير (كيمياء)" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-an mw-list-item"><a href="https://an.wikipedia.org/wiki/Isotopo" title="Isotopo – Aragonese" lang="an" hreflang="an" data-title="Isotopo" data-language-autonym="Aragonés" data-language-local-name="Aragonese" class="interlanguage-link-target"><span>Aragonés</span></a></li><li class="interlanguage-link interwiki-ast mw-list-item"><a href="https://ast.wikipedia.org/wiki/Is%C3%B3topu" title="Isótopu – Asturian" lang="ast" hreflang="ast" data-title="Isótopu" data-language-autonym="Asturianu" data-language-local-name="Asturian" class="interlanguage-link-target"><span>Asturianu</span></a></li><li class="interlanguage-link interwiki-az mw-list-item"><a href="https://az.wikipedia.org/wiki/%C4%B0zotop" title="İzotop – Azerbaijani" lang="az" hreflang="az" data-title="İzotop" data-language-autonym="Azərbaycanca" data-language-local-name="Azerbaijani" class="interlanguage-link-target"><span>Azərbaycanca</span></a></li><li class="interlanguage-link interwiki-ban mw-list-item"><a href="https://ban.wikipedia.org/wiki/Isotop" title="Isotop – Balinese" lang="ban" hreflang="ban" data-title="Isotop" data-language-autonym="Basa Bali" data-language-local-name="Balinese" class="interlanguage-link-target"><span>Basa Bali</span></a></li><li class="interlanguage-link interwiki-bn mw-list-item"><a href="https://bn.wikipedia.org/wiki/%E0%A6%86%E0%A6%87%E0%A6%B8%E0%A7%8B%E0%A6%9F%E0%A7%8B%E0%A6%AA" title="আইসোটোপ – Bangla" lang="bn" hreflang="bn" data-title="আইসোটোপ" data-language-autonym="বাংলা" data-language-local-name="Bangla" class="interlanguage-link-target"><span>বাংলা</span></a></li><li class="interlanguage-link interwiki-zh-min-nan mw-list-item"><a href="https://zh-min-nan.wikipedia.org/wiki/T%C3%B4ng-%C5%ABi-s%C3%B2%CD%98" title="Tông-ūi-sò͘ – Minnan" lang="nan" hreflang="nan" data-title="Tông-ūi-sò͘" data-language-autonym="閩南語 / Bân-lâm-gú" data-language-local-name="Minnan" class="interlanguage-link-target"><span>閩南語 / Bân-lâm-gú</span></a></li><li class="interlanguage-link interwiki-be mw-list-item"><a href="https://be.wikipedia.org/wiki/%D0%86%D0%B7%D0%B0%D1%82%D0%BE%D0%BF" title="Ізатоп – Belarusian" lang="be" hreflang="be" data-title="Ізатоп" data-language-autonym="Беларуская" data-language-local-name="Belarusian" class="interlanguage-link-target"><span>Беларуская</span></a></li><li class="interlanguage-link interwiki-be-x-old mw-list-item"><a href="https://be-tarask.wikipedia.org/wiki/%D0%86%D0%B7%D0%B0%D1%82%D0%BE%D0%BF" title="Ізатоп – Belarusian (Taraškievica orthography)" lang="be-tarask" hreflang="be-tarask" data-title="Ізатоп" data-language-autonym="Беларуская (тарашкевіца)" data-language-local-name="Belarusian (Taraškievica orthography)" class="interlanguage-link-target"><span>Беларуская (тарашкевіца)</span></a></li><li class="interlanguage-link interwiki-bh mw-list-item"><a href="https://bh.wikipedia.org/wiki/%E0%A4%86%E0%A4%87%E0%A4%B8%E0%A5%8B%E0%A4%9F%E0%A5%8B%E0%A4%AA" title="आइसोटोप – Bhojpuri" lang="bh" hreflang="bh" data-title="आइसोटोप" data-language-autonym="भोजपुरी" data-language-local-name="Bhojpuri" class="interlanguage-link-target"><span>भोजपुरी</span></a></li><li class="interlanguage-link interwiki-bcl mw-list-item"><a href="https://bcl.wikipedia.org/wiki/Isotopo" title="Isotopo – Central Bikol" lang="bcl" hreflang="bcl" data-title="Isotopo" data-language-autonym="Bikol Central" data-language-local-name="Central Bikol" class="interlanguage-link-target"><span>Bikol Central</span></a></li><li class="interlanguage-link interwiki-bg mw-list-item"><a href="https://bg.wikipedia.org/wiki/%D0%98%D0%B7%D0%BE%D1%82%D0%BE%D0%BF" title="Изотоп – Bulgarian" lang="bg" hreflang="bg" data-title="Изотоп" data-language-autonym="Български" data-language-local-name="Bulgarian" class="interlanguage-link-target"><span>Български</span></a></li><li class="interlanguage-link interwiki-bs mw-list-item"><a href="https://bs.wikipedia.org/wiki/Izotop" title="Izotop – Bosnian" lang="bs" hreflang="bs" data-title="Izotop" data-language-autonym="Bosanski" data-language-local-name="Bosnian" class="interlanguage-link-target"><span>Bosanski</span></a></li><li class="interlanguage-link interwiki-br mw-list-item"><a href="https://br.wikipedia.org/wiki/Izotop" title="Izotop – Breton" lang="br" hreflang="br" data-title="Izotop" data-language-autonym="Brezhoneg" data-language-local-name="Breton" class="interlanguage-link-target"><span>Brezhoneg</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Is%C3%B2top" title="Isòtop – Catalan" lang="ca" hreflang="ca" data-title="Isòtop" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-cv mw-list-item"><a href="https://cv.wikipedia.org/wiki/%D0%98%D0%B7%D0%BE%D1%82%D0%BE%D0%BF" title="Изотоп – Chuvash" lang="cv" hreflang="cv" data-title="Изотоп" data-language-autonym="Чӑвашла" data-language-local-name="Chuvash" class="interlanguage-link-target"><span>Чӑвашла</span></a></li><li class="interlanguage-link interwiki-ceb mw-list-item"><a href="https://ceb.wikipedia.org/wiki/Isotop" title="Isotop – Cebuano" lang="ceb" hreflang="ceb" data-title="Isotop" data-language-autonym="Cebuano" data-language-local-name="Cebuano" class="interlanguage-link-target"><span>Cebuano</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/Izotop" title="Izotop – Czech" lang="cs" hreflang="cs" data-title="Izotop" data-language-autonym="Čeština" data-language-local-name="Czech" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-sn mw-list-item"><a href="https://sn.wikipedia.org/wiki/Enzanhara" title="Enzanhara – Shona" lang="sn" hreflang="sn" data-title="Enzanhara" data-language-autonym="ChiShona" data-language-local-name="Shona" class="interlanguage-link-target"><span>ChiShona</span></a></li><li class="interlanguage-link interwiki-cy mw-list-item"><a href="https://cy.wikipedia.org/wiki/Isotop" title="Isotop – Welsh" lang="cy" hreflang="cy" data-title="Isotop" data-language-autonym="Cymraeg" data-language-local-name="Welsh" class="interlanguage-link-target"><span>Cymraeg</span></a></li><li class="interlanguage-link interwiki-da mw-list-item"><a href="https://da.wikipedia.org/wiki/Isotop" title="Isotop – Danish" lang="da" hreflang="da" data-title="Isotop" data-language-autonym="Dansk" data-language-local-name="Danish" class="interlanguage-link-target"><span>Dansk</span></a></li><li class="interlanguage-link interwiki-ary mw-list-item"><a href="https://ary.wikipedia.org/wiki/%D8%A5%D9%8A%D8%B2%D9%88%D8%B7%D9%88%D9%BE" title="إيزوطوپ – Moroccan Arabic" lang="ary" hreflang="ary" data-title="إيزوطوپ" data-language-autonym="الدارجة" data-language-local-name="Moroccan Arabic" class="interlanguage-link-target"><span>الدارجة</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Isotop" title="Isotop – German" lang="de" hreflang="de" data-title="Isotop" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-et mw-list-item"><a href="https://et.wikipedia.org/wiki/Isotoop" title="Isotoop – Estonian" lang="et" hreflang="et" data-title="Isotoop" data-language-autonym="Eesti" data-language-local-name="Estonian" class="interlanguage-link-target"><span>Eesti</span></a></li><li class="interlanguage-link interwiki-el mw-list-item"><a href="https://el.wikipedia.org/wiki/%CE%99%CF%83%CF%8C%CF%84%CE%BF%CF%80%CE%BF" title="Ισότοπο – Greek" lang="el" hreflang="el" data-title="Ισότοπο" data-language-autonym="Ελληνικά" data-language-local-name="Greek" class="interlanguage-link-target"><span>Ελληνικά</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Is%C3%B3topo" title="Isótopo – Spanish" lang="es" hreflang="es" data-title="Isótopo" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-eo mw-list-item"><a href="https://eo.wikipedia.org/wiki/Izotopo" title="Izotopo – Esperanto" lang="eo" hreflang="eo" data-title="Izotopo" data-language-autonym="Esperanto" data-language-local-name="Esperanto" class="interlanguage-link-target"><span>Esperanto</span></a></li><li class="interlanguage-link interwiki-eu mw-list-item"><a href="https://eu.wikipedia.org/wiki/Isotopo" title="Isotopo – Basque" lang="eu" hreflang="eu" data-title="Isotopo" data-language-autonym="Euskara" data-language-local-name="Basque" class="interlanguage-link-target"><span>Euskara</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%D8%A7%DB%8C%D8%B2%D9%88%D8%AA%D9%88%D9%BE" title="ایزوتوپ – Persian" lang="fa" hreflang="fa" data-title="ایزوتوپ" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fo mw-list-item"><a href="https://fo.wikipedia.org/wiki/Isotopar" title="Isotopar – Faroese" lang="fo" hreflang="fo" data-title="Isotopar" data-language-autonym="Føroyskt" data-language-local-name="Faroese" class="interlanguage-link-target"><span>Føroyskt</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/Isotope" title="Isotope – French" lang="fr" hreflang="fr" data-title="Isotope" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-ga mw-list-item"><a href="https://ga.wikipedia.org/wiki/Iseat%C3%B3p" title="Iseatóp – Irish" lang="ga" hreflang="ga" data-title="Iseatóp" data-language-autonym="Gaeilge" data-language-local-name="Irish" class="interlanguage-link-target"><span>Gaeilge</span></a></li><li class="interlanguage-link interwiki-gl mw-list-item"><a href="https://gl.wikipedia.org/wiki/Is%C3%B3topo" title="Isótopo – Galician" lang="gl" hreflang="gl" data-title="Isótopo" data-language-autonym="Galego" data-language-local-name="Galician" class="interlanguage-link-target"><span>Galego</span></a></li><li class="interlanguage-link interwiki-gan mw-list-item"><a href="https://gan.wikipedia.org/wiki/%E5%90%8C%E4%BD%8D%E7%B4%A0" title="同位素 – Gan" lang="gan" hreflang="gan" data-title="同位素" data-language-autonym="贛語" data-language-local-name="Gan" class="interlanguage-link-target"><span>贛語</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/%EB%8F%99%EC%9C%84_%EC%9B%90%EC%86%8C" title="동위 원소 – Korean" lang="ko" hreflang="ko" data-title="동위 원소" data-language-autonym="한국어" data-language-local-name="Korean" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-hy mw-list-item"><a href="https://hy.wikipedia.org/wiki/%D4%BB%D5%A6%D5%B8%D5%BF%D5%B8%D5%BA%D5%B6%D5%A5%D6%80" title="Իզոտոպներ – Armenian" lang="hy" hreflang="hy" data-title="Իզոտոպներ" data-language-autonym="Հայերեն" data-language-local-name="Armenian" class="interlanguage-link-target"><span>Հայերեն</span></a></li><li class="interlanguage-link interwiki-hi mw-list-item"><a href="https://hi.wikipedia.org/wiki/%E0%A4%B8%E0%A4%AE%E0%A4%B8%E0%A5%8D%E0%A4%A5%E0%A4%BE%E0%A4%A8%E0%A4%BF%E0%A4%95" title="समस्थानिक – Hindi" lang="hi" hreflang="hi" data-title="समस्थानिक" data-language-autonym="हिन्दी" data-language-local-name="Hindi" class="interlanguage-link-target"><span>हिन्दी</span></a></li><li class="interlanguage-link interwiki-hr mw-list-item"><a href="https://hr.wikipedia.org/wiki/Izotop" title="Izotop – Croatian" lang="hr" hreflang="hr" data-title="Izotop" data-language-autonym="Hrvatski" data-language-local-name="Croatian" class="interlanguage-link-target"><span>Hrvatski</span></a></li><li class="interlanguage-link interwiki-io mw-list-item"><a href="https://io.wikipedia.org/wiki/Izotopo" title="Izotopo – Ido" lang="io" hreflang="io" data-title="Izotopo" data-language-autonym="Ido" data-language-local-name="Ido" class="interlanguage-link-target"><span>Ido</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Isotop" title="Isotop – Indonesian" lang="id" hreflang="id" data-title="Isotop" data-language-autonym="Bahasa Indonesia" data-language-local-name="Indonesian" class="interlanguage-link-target"><span>Bahasa Indonesia</span></a></li><li class="interlanguage-link interwiki-ia mw-list-item"><a href="https://ia.wikipedia.org/wiki/Isotopo" title="Isotopo – Interlingua" lang="ia" hreflang="ia" data-title="Isotopo" data-language-autonym="Interlingua" data-language-local-name="Interlingua" class="interlanguage-link-target"><span>Interlingua</span></a></li><li class="interlanguage-link interwiki-zu mw-list-item"><a href="https://zu.wikipedia.org/wiki/IChembe" title="IChembe – Zulu" lang="zu" hreflang="zu" data-title="IChembe" data-language-autonym="IsiZulu" data-language-local-name="Zulu" class="interlanguage-link-target"><span>IsiZulu</span></a></li><li class="interlanguage-link interwiki-is mw-list-item"><a href="https://is.wikipedia.org/wiki/Sams%C3%A6ta" title="Samsæta – Icelandic" lang="is" hreflang="is" data-title="Samsæta" data-language-autonym="Íslenska" data-language-local-name="Icelandic" class="interlanguage-link-target"><span>Íslenska</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Isotopo" title="Isotopo – Italian" lang="it" hreflang="it" data-title="Isotopo" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-he mw-list-item"><a href="https://he.wikipedia.org/wiki/%D7%90%D7%99%D7%96%D7%95%D7%98%D7%95%D7%A4" title="איזוטופ – Hebrew" lang="he" hreflang="he" data-title="איזוטופ" data-language-autonym="עברית" data-language-local-name="Hebrew" class="interlanguage-link-target"><span>עברית</span></a></li><li class="interlanguage-link interwiki-jv mw-list-item"><a href="https://jv.wikipedia.org/wiki/Isotop" title="Isotop – Javanese" lang="jv" hreflang="jv" data-title="Isotop" data-language-autonym="Jawa" data-language-local-name="Javanese" class="interlanguage-link-target"><span>Jawa</span></a></li><li class="interlanguage-link interwiki-kn mw-list-item"><a href="https://kn.wikipedia.org/wiki/%E0%B2%B8%E0%B2%AE%E0%B2%B8%E0%B3%8D%E0%B2%A5%E0%B2%BE%E0%B2%A8%E0%B2%BF" title="ಸಮಸ್ಥಾನಿ – Kannada" lang="kn" hreflang="kn" data-title="ಸಮಸ್ಥಾನಿ" data-language-autonym="ಕನ್ನಡ" data-language-local-name="Kannada" class="interlanguage-link-target"><span>ಕನ್ನಡ</span></a></li><li class="interlanguage-link interwiki-ka mw-list-item"><a href="https://ka.wikipedia.org/wiki/%E1%83%98%E1%83%96%E1%83%9D%E1%83%A2%E1%83%9D%E1%83%9E%E1%83%94%E1%83%91%E1%83%98" title="იზოტოპები – Georgian" lang="ka" hreflang="ka" data-title="იზოტოპები" data-language-autonym="ქართული" data-language-local-name="Georgian" class="interlanguage-link-target"><span>ქართული</span></a></li><li class="interlanguage-link interwiki-kk mw-list-item"><a href="https://kk.wikipedia.org/wiki/%D0%98%D0%B7%D0%BE%D1%82%D0%BE%D0%BF%D1%82%D0%B0%D1%80" title="Изотоптар – Kazakh" lang="kk" hreflang="kk" data-title="Изотоптар" data-language-autonym="Қазақша" data-language-local-name="Kazakh" class="interlanguage-link-target"><span>Қазақша</span></a></li><li class="interlanguage-link interwiki-sw mw-list-item"><a href="https://sw.wikipedia.org/wiki/Isotopi" title="Isotopi – Swahili" lang="sw" hreflang="sw" data-title="Isotopi" data-language-autonym="Kiswahili" data-language-local-name="Swahili" class="interlanguage-link-target"><span>Kiswahili</span></a></li><li class="interlanguage-link interwiki-ht mw-list-item"><a href="https://ht.wikipedia.org/wiki/Izot%C3%B2p" title="Izotòp – Haitian Creole" lang="ht" hreflang="ht" data-title="Izotòp" data-language-autonym="Kreyòl ayisyen" data-language-local-name="Haitian Creole" class="interlanguage-link-target"><span>Kreyòl ayisyen</span></a></li><li class="interlanguage-link interwiki-ku mw-list-item"><a href="https://ku.wikipedia.org/wiki/%C3%8Ezotop" title="Îzotop – Kurdish" lang="ku" hreflang="ku" data-title="Îzotop" data-language-autonym="Kurdî" data-language-local-name="Kurdish" class="interlanguage-link-target"><span>Kurdî</span></a></li><li class="interlanguage-link interwiki-ky mw-list-item"><a href="https://ky.wikipedia.org/wiki/%D0%98%D0%B7%D0%BE%D1%82%D0%BE%D0%BF%D1%82%D0%BE%D1%80" title="Изотоптор – Kyrgyz" lang="ky" hreflang="ky" data-title="Изотоптор" data-language-autonym="Кыргызча" data-language-local-name="Kyrgyz" class="interlanguage-link-target"><span>Кыргызча</span></a></li><li class="interlanguage-link interwiki-la mw-list-item"><a href="https://la.wikipedia.org/wiki/Isotopus" title="Isotopus – Latin" lang="la" hreflang="la" data-title="Isotopus" data-language-autonym="Latina" data-language-local-name="Latin" class="interlanguage-link-target"><span>Latina</span></a></li><li class="interlanguage-link interwiki-lv mw-list-item"><a href="https://lv.wikipedia.org/wiki/Izotops" title="Izotops – Latvian" lang="lv" hreflang="lv" data-title="Izotops" data-language-autonym="Latviešu" data-language-local-name="Latvian" class="interlanguage-link-target"><span>Latviešu</span></a></li><li class="interlanguage-link interwiki-lt mw-list-item"><a href="https://lt.wikipedia.org/wiki/Izotopas" title="Izotopas – Lithuanian" lang="lt" hreflang="lt" data-title="Izotopas" data-language-autonym="Lietuvių" data-language-local-name="Lithuanian" class="interlanguage-link-target"><span>Lietuvių</span></a></li><li class="interlanguage-link interwiki-li mw-list-item"><a href="https://li.wikipedia.org/wiki/Isotoop" title="Isotoop – Limburgish" lang="li" hreflang="li" data-title="Isotoop" data-language-autonym="Limburgs" data-language-local-name="Limburgish" class="interlanguage-link-target"><span>Limburgs</span></a></li><li class="interlanguage-link interwiki-lmo mw-list-item"><a href="https://lmo.wikipedia.org/wiki/Isotop" title="Isotop – Lombard" lang="lmo" hreflang="lmo" data-title="Isotop" data-language-autonym="Lombard" data-language-local-name="Lombard" class="interlanguage-link-target"><span>Lombard</span></a></li><li class="interlanguage-link interwiki-hu mw-list-item"><a href="https://hu.wikipedia.org/wiki/Izot%C3%B3p" title="Izotóp – Hungarian" lang="hu" hreflang="hu" data-title="Izotóp" data-language-autonym="Magyar" data-language-local-name="Hungarian" class="interlanguage-link-target"><span>Magyar</span></a></li><li class="interlanguage-link interwiki-mk mw-list-item"><a href="https://mk.wikipedia.org/wiki/%D0%98%D0%B7%D0%BE%D1%82%D0%BE%D0%BF" title="Изотоп – Macedonian" lang="mk" hreflang="mk" data-title="Изотоп" data-language-autonym="Македонски" data-language-local-name="Macedonian" class="interlanguage-link-target"><span>Македонски</span></a></li><li class="interlanguage-link interwiki-mg mw-list-item"><a href="https://mg.wikipedia.org/wiki/Miratoerana" title="Miratoerana – Malagasy" lang="mg" hreflang="mg" data-title="Miratoerana" data-language-autonym="Malagasy" data-language-local-name="Malagasy" class="interlanguage-link-target"><span>Malagasy</span></a></li><li class="interlanguage-link interwiki-ml mw-list-item"><a href="https://ml.wikipedia.org/wiki/%E0%B4%90%E0%B4%B8%E0%B5%8B%E0%B4%9F%E0%B5%8B%E0%B4%AA%E0%B5%8D%E0%B4%AA%E0%B5%8D" title="ഐസോടോപ്പ് – Malayalam" lang="ml" hreflang="ml" data-title="ഐസോടോപ്പ്" data-language-autonym="മലയാളം" data-language-local-name="Malayalam" class="interlanguage-link-target"><span>മലയാളം</span></a></li><li class="interlanguage-link interwiki-mr mw-list-item"><a href="https://mr.wikipedia.org/wiki/%E0%A4%B8%E0%A4%AE%E0%A4%B8%E0%A5%8D%E0%A4%A5%E0%A4%BE%E0%A4%A8%E0%A4%BF%E0%A4%95%E0%A5%87" title="समस्थानिके – Marathi" lang="mr" hreflang="mr" data-title="समस्थानिके" data-language-autonym="मराठी" data-language-local-name="Marathi" class="interlanguage-link-target"><span>मराठी</span></a></li><li class="interlanguage-link interwiki-ms mw-list-item"><a href="https://ms.wikipedia.org/wiki/Isotop" title="Isotop – Malay" lang="ms" hreflang="ms" data-title="Isotop" data-language-autonym="Bahasa Melayu" data-language-local-name="Malay" class="interlanguage-link-target"><span>Bahasa Melayu</span></a></li><li class="interlanguage-link interwiki-mn mw-list-item"><a href="https://mn.wikipedia.org/wiki/%D0%98%D0%B7%D0%BE%D1%82%D0%BE%D0%BF" title="Изотоп – Mongolian" lang="mn" hreflang="mn" data-title="Изотоп" data-language-autonym="Монгол" data-language-local-name="Mongolian" class="interlanguage-link-target"><span>Монгол</span></a></li><li class="interlanguage-link interwiki-my mw-list-item"><a href="https://my.wikipedia.org/wiki/%E1%80%A1%E1%80%AD%E1%80%AF%E1%80%84%E1%80%BA%E1%80%86%E1%80%AD%E1%80%AF%E1%80%90%E1%80%AF%E1%80%95%E1%80%BA" title="အိုင်ဆိုတုပ် – Burmese" lang="my" hreflang="my" data-title="အိုင်ဆိုတုပ်" data-language-autonym="မြန်မာဘာသာ" data-language-local-name="Burmese" class="interlanguage-link-target"><span>မြန်မာဘာသာ</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Isotoop" title="Isotoop – Dutch" lang="nl" hreflang="nl" data-title="Isotoop" data-language-autonym="Nederlands" data-language-local-name="Dutch" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-ne mw-list-item"><a href="https://ne.wikipedia.org/wiki/%E0%A4%B8%E0%A4%AE%E0%A4%B8%E0%A5%8D%E0%A4%A5%E0%A4%BE%E0%A4%A8%E0%A4%BF%E0%A4%95" title="समस्थानिक – Nepali" lang="ne" hreflang="ne" data-title="समस्थानिक" data-language-autonym="नेपाली" data-language-local-name="Nepali" class="interlanguage-link-target"><span>नेपाली</span></a></li><li class="interlanguage-link interwiki-new mw-list-item"><a href="https://new.wikipedia.org/wiki/%E0%A4%86%E0%A4%87%E0%A4%B8%E0%A5%8B%E0%A4%9F%E0%A5%8B%E0%A4%AA" title="आइसोटोप – Newari" lang="new" hreflang="new" data-title="आइसोटोप" data-language-autonym="नेपाल भाषा" data-language-local-name="Newari" class="interlanguage-link-target"><span>नेपाल भाषा</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%E5%90%8C%E4%BD%8D%E4%BD%93" title="同位体 – Japanese" lang="ja" hreflang="ja" data-title="同位体" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-frr mw-list-item"><a href="https://frr.wikipedia.org/wiki/Isotoop" title="Isotoop – Northern Frisian" lang="frr" hreflang="frr" data-title="Isotoop" data-language-autonym="Nordfriisk" data-language-local-name="Northern Frisian" class="interlanguage-link-target"><span>Nordfriisk</span></a></li><li class="interlanguage-link interwiki-no mw-list-item"><a href="https://no.wikipedia.org/wiki/Isotop" title="Isotop – Norwegian Bokmål" lang="nb" hreflang="nb" data-title="Isotop" data-language-autonym="Norsk bokmål" data-language-local-name="Norwegian Bokmål" class="interlanguage-link-target"><span>Norsk bokmål</span></a></li><li class="interlanguage-link interwiki-nn mw-list-item"><a href="https://nn.wikipedia.org/wiki/Isotop" title="Isotop – Norwegian Nynorsk" lang="nn" hreflang="nn" data-title="Isotop" data-language-autonym="Norsk nynorsk" data-language-local-name="Norwegian Nynorsk" class="interlanguage-link-target"><span>Norsk nynorsk</span></a></li><li class="interlanguage-link interwiki-nov mw-list-item"><a href="https://nov.wikipedia.org/wiki/Isotope" title="Isotope – Novial" lang="nov" hreflang="nov" data-title="Isotope" data-language-autonym="Novial" data-language-local-name="Novial" class="interlanguage-link-target"><span>Novial</span></a></li><li class="interlanguage-link interwiki-oc mw-list-item"><a href="https://oc.wikipedia.org/wiki/Isot%C3%B2p" title="Isotòp – Occitan" lang="oc" hreflang="oc" data-title="Isotòp" data-language-autonym="Occitan" data-language-local-name="Occitan" class="interlanguage-link-target"><span>Occitan</span></a></li><li class="interlanguage-link interwiki-uz mw-list-item"><a href="https://uz.wikipedia.org/wiki/Izotoplar" title="Izotoplar – Uzbek" lang="uz" hreflang="uz" data-title="Izotoplar" data-language-autonym="Oʻzbekcha / ўзбекча" data-language-local-name="Uzbek" class="interlanguage-link-target"><span>Oʻzbekcha / ўзбекча</span></a></li><li class="interlanguage-link interwiki-pa mw-list-item"><a href="https://pa.wikipedia.org/wiki/%E0%A8%86%E0%A8%88%E0%A8%B8%E0%A9%8B%E0%A8%9F%E0%A9%8B%E0%A8%AA" title="ਆਈਸੋਟੋਪ – Punjabi" lang="pa" hreflang="pa" data-title="ਆਈਸੋਟੋਪ" data-language-autonym="ਪੰਜਾਬੀ" data-language-local-name="Punjabi" class="interlanguage-link-target"><span>ਪੰਜਾਬੀ</span></a></li><li class="interlanguage-link interwiki-pnb mw-list-item"><a href="https://pnb.wikipedia.org/wiki/%D8%A2%D8%A6%DB%8C%D8%B3%D9%88%D9%B9%D9%88%D9%BE" title="آئیسوٹوپ – Western Punjabi" lang="pnb" hreflang="pnb" data-title="آئیسوٹوپ" data-language-autonym="پنجابی" data-language-local-name="Western Punjabi" class="interlanguage-link-target"><span>پنجابی</span></a></li><li class="interlanguage-link interwiki-nds mw-list-item"><a href="https://nds.wikipedia.org/wiki/Isotop" title="Isotop – Low German" lang="nds" hreflang="nds" data-title="Isotop" data-language-autonym="Plattdüütsch" data-language-local-name="Low German" class="interlanguage-link-target"><span>Plattdüütsch</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/Izotopy" title="Izotopy – Polish" lang="pl" hreflang="pl" data-title="Izotopy" data-language-autonym="Polski" data-language-local-name="Polish" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/Is%C3%B3topo" title="Isótopo – Portuguese" lang="pt" hreflang="pt" data-title="Isótopo" data-language-autonym="Português" data-language-local-name="Portuguese" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-ro mw-list-item"><a href="https://ro.wikipedia.org/wiki/Izotop" title="Izotop – Romanian" lang="ro" hreflang="ro" data-title="Izotop" data-language-autonym="Română" data-language-local-name="Romanian" class="interlanguage-link-target"><span>Română</span></a></li><li class="interlanguage-link interwiki-rue mw-list-item"><a href="https://rue.wikipedia.org/wiki/%D0%98%D0%B7%D0%BE%D1%82%D0%BE%D0%BF" title="Изотоп – Rusyn" lang="rue" hreflang="rue" data-title="Изотоп" data-language-autonym="Русиньскый" data-language-local-name="Rusyn" class="interlanguage-link-target"><span>Русиньскый</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/%D0%98%D0%B7%D0%BE%D1%82%D0%BE%D0%BF%D1%8B" title="Изотопы – Russian" lang="ru" hreflang="ru" data-title="Изотопы" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-skr mw-list-item"><a href="https://skr.wikipedia.org/wiki/%D8%A2%D8%A6%D8%B3%D9%88%D9%B9%D9%88%D9%BE" title="آئسوٹوپ – Saraiki" lang="skr" hreflang="skr" data-title="آئسوٹوپ" data-language-autonym="سرائیکی" data-language-local-name="Saraiki" class="interlanguage-link-target"><span>سرائیکی</span></a></li><li class="interlanguage-link interwiki-sco mw-list-item"><a href="https://sco.wikipedia.org/wiki/Isotope" title="Isotope – Scots" lang="sco" hreflang="sco" data-title="Isotope" data-language-autonym="Scots" data-language-local-name="Scots" class="interlanguage-link-target"><span>Scots</span></a></li><li class="interlanguage-link interwiki-stq mw-list-item"><a href="https://stq.wikipedia.org/wiki/Isotop" title="Isotop – Saterland Frisian" lang="stq" hreflang="stq" data-title="Isotop" data-language-autonym="Seeltersk" data-language-local-name="Saterland Frisian" class="interlanguage-link-target"><span>Seeltersk</span></a></li><li class="interlanguage-link interwiki-sq mw-list-item"><a href="https://sq.wikipedia.org/wiki/Izotopi" title="Izotopi – Albanian" lang="sq" hreflang="sq" data-title="Izotopi" data-language-autonym="Shqip" data-language-local-name="Albanian" class="interlanguage-link-target"><span>Shqip</span></a></li><li class="interlanguage-link interwiki-si mw-list-item"><a href="https://si.wikipedia.org/wiki/%E0%B7%83%E0%B6%B8%E0%B7%83%E0%B7%8A%E0%B6%AE%E0%B7%8F%E0%B6%B1%E0%B7%92%E0%B6%9A" title="සමස්ථානික – Sinhala" lang="si" hreflang="si" data-title="සමස්ථානික" data-language-autonym="සිංහල" data-language-local-name="Sinhala" class="interlanguage-link-target"><span>සිංහල</span></a></li><li class="interlanguage-link interwiki-simple mw-list-item"><a href="https://simple.wikipedia.org/wiki/Isotope" title="Isotope – Simple English" lang="en-simple" hreflang="en-simple" data-title="Isotope" data-language-autonym="Simple English" data-language-local-name="Simple English" class="interlanguage-link-target"><span>Simple English</span></a></li><li class="interlanguage-link interwiki-sd mw-list-item"><a href="https://sd.wikipedia.org/wiki/%DA%BE%D9%85%D8%B2%D8%A7%D8%AF" title="ھمزاد – Sindhi" lang="sd" hreflang="sd" data-title="ھمزاد" data-language-autonym="سنڌي" data-language-local-name="Sindhi" class="interlanguage-link-target"><span>سنڌي</span></a></li><li class="interlanguage-link interwiki-sk mw-list-item"><a href="https://sk.wikipedia.org/wiki/Izotop" title="Izotop – Slovak" lang="sk" hreflang="sk" data-title="Izotop" data-language-autonym="Slovenčina" data-language-local-name="Slovak" class="interlanguage-link-target"><span>Slovenčina</span></a></li><li class="interlanguage-link interwiki-sl mw-list-item"><a href="https://sl.wikipedia.org/wiki/Izotop" title="Izotop – Slovenian" lang="sl" hreflang="sl" data-title="Izotop" data-language-autonym="Slovenščina" data-language-local-name="Slovenian" class="interlanguage-link-target"><span>Slovenščina</span></a></li><li class="interlanguage-link interwiki-so mw-list-item"><a href="https://so.wikipedia.org/wiki/Isotope" title="Isotope – Somali" lang="so" hreflang="so" data-title="Isotope" data-language-autonym="Soomaaliga" data-language-local-name="Somali" class="interlanguage-link-target"><span>Soomaaliga</span></a></li><li class="interlanguage-link interwiki-sr mw-list-item"><a href="https://sr.wikipedia.org/wiki/%D0%98%D0%B7%D0%BE%D1%82%D0%BE%D0%BF" title="Изотоп – Serbian" lang="sr" hreflang="sr" data-title="Изотоп" data-language-autonym="Српски / srpski" data-language-local-name="Serbian" class="interlanguage-link-target"><span>Српски / srpski</span></a></li><li class="interlanguage-link interwiki-sh mw-list-item"><a href="https://sh.wikipedia.org/wiki/Izotop" title="Izotop – Serbo-Croatian" lang="sh" hreflang="sh" data-title="Izotop" data-language-autonym="Srpskohrvatski / српскохрватски" data-language-local-name="Serbo-Croatian" class="interlanguage-link-target"><span>Srpskohrvatski / српскохрватски</span></a></li><li class="interlanguage-link interwiki-su mw-list-item"><a href="https://su.wikipedia.org/wiki/Isotop" title="Isotop – Sundanese" lang="su" hreflang="su" data-title="Isotop" data-language-autonym="Sunda" data-language-local-name="Sundanese" class="interlanguage-link-target"><span>Sunda</span></a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/Isotooppi" title="Isotooppi – Finnish" lang="fi" hreflang="fi" data-title="Isotooppi" data-language-autonym="Suomi" data-language-local-name="Finnish" class="interlanguage-link-target"><span>Suomi</span></a></li><li class="interlanguage-link interwiki-sv mw-list-item"><a href="https://sv.wikipedia.org/wiki/Isotop" title="Isotop – Swedish" lang="sv" hreflang="sv" data-title="Isotop" data-language-autonym="Svenska" data-language-local-name="Swedish" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-tl mw-list-item"><a href="https://tl.wikipedia.org/wiki/Isotope" title="Isotope – Tagalog" lang="tl" hreflang="tl" data-title="Isotope" data-language-autonym="Tagalog" data-language-local-name="Tagalog" class="interlanguage-link-target"><span>Tagalog</span></a></li><li class="interlanguage-link interwiki-ta mw-list-item"><a href="https://ta.wikipedia.org/wiki/%E0%AE%93%E0%AE%B0%E0%AE%BF%E0%AE%9F%E0%AE%A4%E0%AF%8D%E0%AE%A4%E0%AE%BE%E0%AE%A9%E0%AF%8D" title="ஓரிடத்தான் – Tamil" lang="ta" hreflang="ta" data-title="ஓரிடத்தான்" data-language-autonym="தமிழ்" data-language-local-name="Tamil" class="interlanguage-link-target"><span>தமிழ்</span></a></li><li class="interlanguage-link interwiki-kab mw-list-item"><a href="https://kab.wikipedia.org/wiki/Anyat" title="Anyat – Kabyle" lang="kab" hreflang="kab" data-title="Anyat" data-language-autonym="Taqbaylit" data-language-local-name="Kabyle" class="interlanguage-link-target"><span>Taqbaylit</span></a></li><li class="interlanguage-link interwiki-te mw-list-item"><a href="https://te.wikipedia.org/wiki/%E0%B0%90%E0%B0%B8%E0%B1%8B%E0%B0%9F%E0%B1%8B%E0%B0%AA%E0%B1%81%E0%B0%B2%E0%B1%81" title="ఐసోటోపులు – Telugu" lang="te" hreflang="te" data-title="ఐసోటోపులు" data-language-autonym="తెలుగు" data-language-local-name="Telugu" class="interlanguage-link-target"><span>తెలుగు</span></a></li><li class="interlanguage-link interwiki-th mw-list-item"><a href="https://th.wikipedia.org/wiki/%E0%B9%84%E0%B8%AD%E0%B9%82%E0%B8%8B%E0%B9%82%E0%B8%97%E0%B8%9B" title="ไอโซโทป – Thai" lang="th" hreflang="th" data-title="ไอโซโทป" data-language-autonym="ไทย" data-language-local-name="Thai" class="interlanguage-link-target"><span>ไทย</span></a></li><li class="interlanguage-link interwiki-tr mw-list-item"><a href="https://tr.wikipedia.org/wiki/%C4%B0zotop" title="İzotop – Turkish" lang="tr" hreflang="tr" data-title="İzotop" data-language-autonym="Türkçe" data-language-local-name="Turkish" class="interlanguage-link-target"><span>Türkçe</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/%D0%86%D0%B7%D0%BE%D1%82%D0%BE%D0%BF%D0%B8" title="Ізотопи – Ukrainian" lang="uk" hreflang="uk" data-title="Ізотопи" data-language-autonym="Українська" data-language-local-name="Ukrainian" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-ur mw-list-item"><a href="https://ur.wikipedia.org/wiki/%DB%81%D9%85_%D8%AC%D8%A7" title="ہم جا – Urdu" lang="ur" hreflang="ur" data-title="ہم جا" data-language-autonym="اردو" data-language-local-name="Urdu" class="interlanguage-link-target"><span>اردو</span></a></li><li class="interlanguage-link interwiki-za mw-list-item"><a href="https://za.wikipedia.org/wiki/Doengzvihsuq" title="Doengzvihsuq – Zhuang" lang="za" hreflang="za" data-title="Doengzvihsuq" data-language-autonym="Vahcuengh" data-language-local-name="Zhuang" class="interlanguage-link-target"><span>Vahcuengh</span></a></li><li class="interlanguage-link interwiki-vec mw-list-item"><a href="https://vec.wikipedia.org/wiki/Ix%C3%B2topo" title="Ixòtopo – Venetian" lang="vec" hreflang="vec" data-title="Ixòtopo" data-language-autonym="Vèneto" data-language-local-name="Venetian" class="interlanguage-link-target"><span>Vèneto</span></a></li><li class="interlanguage-link interwiki-vep mw-list-item"><a href="https://vep.wikipedia.org/wiki/Izotop" title="Izotop – Veps" lang="vep" hreflang="vep" data-title="Izotop" data-language-autonym="Vepsän kel’" data-language-local-name="Veps" class="interlanguage-link-target"><span>Vepsän kel’</span></a></li><li class="interlanguage-link interwiki-vi mw-list-item"><a href="https://vi.wikipedia.org/wiki/%C4%90%E1%BB%93ng_v%E1%BB%8B" title="Đồng vị – Vietnamese" lang="vi" hreflang="vi" data-title="Đồng vị" data-language-autonym="Tiếng Việt" data-language-local-name="Vietnamese" class="interlanguage-link-target"><span>Tiếng Việt</span></a></li><li class="interlanguage-link interwiki-zh-classical mw-list-item"><a href="https://zh-classical.wikipedia.org/wiki/%E5%90%8C%E4%BD%8D%E7%B4%A0" title="同位素 – Literary Chinese" lang="lzh" hreflang="lzh" data-title="同位素" data-language-autonym="文言" data-language-local-name="Literary Chinese" class="interlanguage-link-target"><span>文言</span></a></li><li class="interlanguage-link interwiki-war mw-list-item"><a href="https://war.wikipedia.org/wiki/Isotopo" title="Isotopo – Waray" lang="war" hreflang="war" data-title="Isotopo" data-language-autonym="Winaray" data-language-local-name="Waray" class="interlanguage-link-target"><span>Winaray</span></a></li><li class="interlanguage-link interwiki-wuu mw-list-item"><a href="https://wuu.wikipedia.org/wiki/%E5%90%8C%E4%BD%8D%E7%B4%A0" title="同位素 – Wu" lang="wuu" hreflang="wuu" data-title="同位素" data-language-autonym="吴语" 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class="vector-body" aria-labelledby="firstHeading" data-mw-ve-target-container> <div class="vector-body-before-content"> <div class="mw-indicators"> </div> <div id="siteSub" class="noprint">From Wikipedia, the free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"><span class="mw-redirectedfrom">(Redirected from <a href="/w/index.php?title=Isotopes&redirect=no" class="mw-redirect" title="Isotopes">Isotopes</a>)</span></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Different atoms of the same element</div> <style data-mw-deduplicate="TemplateStyles:r1236090951">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media 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screen{html.skin-theme-clientpref-night .mw-parser-output .sidebar:not(.notheme) .sidebar-list-title,html.skin-theme-clientpref-night .mw-parser-output .sidebar:not(.notheme) .sidebar-title-with-pretitle{background:transparent!important}html.skin-theme-clientpref-night .mw-parser-output .sidebar:not(.notheme) .sidebar-title-with-pretitle a{color:var(--color-progressive)!important}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .sidebar:not(.notheme) .sidebar-list-title,html.skin-theme-clientpref-os .mw-parser-output .sidebar:not(.notheme) .sidebar-title-with-pretitle{background:transparent!important}html.skin-theme-clientpref-os .mw-parser-output .sidebar:not(.notheme) .sidebar-title-with-pretitle a{color:var(--color-progressive)!important}}@media print{body.ns-0 .mw-parser-output .sidebar{display:none!important}}</style><table class="sidebar sidebar-collapse nomobile nowraplinks"><tbody><tr><th class="sidebar-title"><a href="/wiki/Nuclear_physics" title="Nuclear physics">Nuclear physics</a></th></tr><tr><td class="sidebar-image"><span typeof="mw:File"><a href="/wiki/File:NuclearReaction.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/4/4b/NuclearReaction.svg/200px-NuclearReaction.svg.png" decoding="async" width="200" height="127" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/4b/NuclearReaction.svg/300px-NuclearReaction.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/4b/NuclearReaction.svg/400px-NuclearReaction.svg.png 2x" data-file-width="550" data-file-height="350" /></a></span></td></tr><tr><td class="sidebar-content hlist"> <ul><li><a href="/wiki/Atomic_nucleus" title="Atomic nucleus">Nucleus</a></li> <li><a href="/wiki/Nucleon" title="Nucleon">Nucleons</a> <ul><li><a href="/wiki/Proton" title="Proton">p</a></li> <li><a href="/wiki/Neutron" title="Neutron">n</a></li></ul></li> <li><a href="/wiki/Nuclear_matter" title="Nuclear matter">Nuclear matter</a></li> <li><a href="/wiki/Nuclear_force" title="Nuclear force">Nuclear force</a></li> <li><a href="/wiki/Nuclear_structure" title="Nuclear structure">Nuclear structure</a></li> <li><a href="/wiki/Nuclear_reaction" title="Nuclear reaction">Nuclear reaction</a></li></ul></td> </tr><tr><td class="sidebar-content hlist"> <div class="sidebar-list mw-collapsible mw-collapsed"><div class="sidebar-list-title" style="color: var(--color-base)"><a href="/wiki/Nuclear_model" class="mw-redirect" title="Nuclear model">Models of the nucleus</a></div><div class="sidebar-list-content mw-collapsible-content"> <ul><li><a href="/wiki/Semi-empirical_mass_formula" title="Semi-empirical mass formula">Liquid drop</a></li> <li><a href="/wiki/Nuclear_shell_model" title="Nuclear shell model">Nuclear shell model</a></li> <li><a href="/wiki/Interacting_boson_model" title="Interacting boson model">Interacting boson model</a></li> <li><a href="/wiki/Ab_initio_methods_(nuclear_physics)" title="Ab initio methods (nuclear physics)">Ab initio</a></li></ul></div></div></td> </tr><tr><td class="sidebar-content hlist"> <div class="sidebar-list mw-collapsible"><div class="sidebar-list-title" style="color: var(--color-base)"><a href="/wiki/Nuclide" title="Nuclide">Nuclides</a>' classification</div><div class="sidebar-list-content mw-collapsible-content"> <ul><li><a class="mw-selflink selflink">Isotopes</a> – equal <a href="/wiki/Atomic_number" title="Atomic number"><i>Z</i></a><br /></li></ul> <ul><li><a href="/wiki/Isobar_(nuclide)" title="Isobar (nuclide)">Isobars</a> – equal <a href="/wiki/Mass_number" title="Mass number"><i>A</i></a></li></ul> <ul><li><a href="/wiki/Isotone" title="Isotone">Isotones</a> – equal <a href="/wiki/Neutron_number" title="Neutron number"><i>N</i></a></li></ul> <ul><li><a href="/wiki/Isodiapher" class="mw-redirect" title="Isodiapher">Isodiaphers</a> – equal <a href="/wiki/Neutron_excess" class="mw-redirect" title="Neutron excess"><i>N</i> − <i>Z</i></a></li></ul> <ul><li><a href="/wiki/Nuclear_isomer" title="Nuclear isomer">Isomers</a> – equal all the above</li></ul> <ul><li><a href="/wiki/Mirror_nuclei" title="Mirror nuclei">Mirror nuclei</a> – <i>Z</i> ↔ <i>N</i></li></ul> <ul><li><a href="/wiki/Stable_isotope" class="mw-redirect" title="Stable isotope">Stable</a></li> <li><a href="/wiki/Magic_number_(physics)" title="Magic number (physics)">Magic</a></li> <li><a href="/wiki/Even_and_odd_atomic_nuclei" title="Even and odd atomic nuclei">Even/odd</a></li> <li><a href="/wiki/Halo_nucleus" title="Halo nucleus">Halo</a> <ul><li><a href="/wiki/Borromean_nucleus" title="Borromean nucleus">Borromean</a></li></ul></li></ul></div></div></td> </tr><tr><td class="sidebar-content hlist"> <div class="sidebar-list mw-collapsible mw-collapsed"><div class="sidebar-list-title" style="color: var(--color-base)">Nuclear stability</div><div class="sidebar-list-content mw-collapsible-content"> <ul><li><a href="/wiki/Nuclear_binding_energy" title="Nuclear binding energy">Binding energy</a></li> <li><a href="/wiki/Proton%E2%80%93neutron_ratio" class="mw-redirect" title="Proton–neutron ratio">p–n ratio</a></li> <li><a href="/wiki/Nuclear_drip_line" title="Nuclear drip line">Drip line</a></li> <li><a href="/wiki/Island_of_stability" title="Island of stability">Island of stability</a></li> <li><a href="/wiki/Valley_of_stability" title="Valley of stability">Valley of stability</a></li> <li><a href="/wiki/Stable_nuclide" title="Stable nuclide">Stable nuclide</a></li></ul></div></div></td> </tr><tr><td class="sidebar-content hlist"> <div class="sidebar-list mw-collapsible mw-collapsed"><div class="sidebar-list-title" style="color: var(--color-base)"><a href="/wiki/Radioactive_decay" title="Radioactive decay">Radioactive decay</a></div><div class="sidebar-list-content mw-collapsible-content"> <ul><li><a href="/wiki/Alpha_decay" title="Alpha decay">Alpha α</a></li> <li><a href="/wiki/Beta_decay" title="Beta decay">Beta β</a> <ul><li><a href="/wiki/Double_beta_decay" title="Double beta decay">2β</a> <ul><li><a href="/wiki/Neutrinoless_double_beta_decay" title="Neutrinoless double beta decay">0v</a></li></ul></li> <li><a href="/wiki/Positron_emission" title="Positron emission">β<sup>+</sup></a></li></ul></li> <li><a href="/wiki/Electron_capture" title="Electron capture">K/L capture</a></li> <li><a href="/wiki/Isomeric_transition" class="mw-redirect" title="Isomeric transition">Isomeric</a> <ul><li><a href="/wiki/Gamma_ray" title="Gamma ray">Gamma γ</a></li> <li><a href="/wiki/Internal_conversion" title="Internal conversion">Internal conversion</a></li></ul></li> <li><a href="/wiki/Spontaneous_fission" title="Spontaneous fission">Spontaneous fission</a></li> <li><a href="/wiki/Cluster_decay" title="Cluster decay">Cluster decay</a></li> <li><a href="/wiki/Neutron_emission" title="Neutron emission">Neutron emission</a></li> <li><a href="/wiki/Proton_emission" title="Proton emission">Proton emission</a></li></ul> <ul><li><a href="/wiki/Decay_energy" title="Decay energy">Decay energy</a></li> <li><a href="/wiki/Decay_chain" title="Decay chain">Decay chain</a></li> <li><a href="/wiki/Decay_product" title="Decay product">Decay product</a></li> <li><a href="/wiki/Radiogenic_nuclide" title="Radiogenic nuclide">Radiogenic nuclide</a></li></ul></div></div></td> </tr><tr><td class="sidebar-content hlist"> <div class="sidebar-list mw-collapsible mw-collapsed"><div class="sidebar-list-title" style="color: var(--color-base)"><a href="/wiki/Nuclear_fission" title="Nuclear fission">Nuclear fission</a></div><div class="sidebar-list-content mw-collapsible-content"> <ul><li><a href="/wiki/Spontaneous_fission" title="Spontaneous fission">Spontaneous</a></li> <li><a href="/wiki/Nuclear_fission_product" title="Nuclear fission product">Products</a> <ul><li><a href="/wiki/Nucleon_pair_breaking_in_fission" title="Nucleon pair breaking in fission">pair breaking</a></li></ul></li> <li><a href="/wiki/Photofission" title="Photofission">Photofission</a></li></ul></div></div></td> </tr><tr><td class="sidebar-content hlist"> <div class="sidebar-list mw-collapsible mw-collapsed"><div class="sidebar-list-title" style="color: var(--color-base)">Capturing processes</div><div class="sidebar-list-content mw-collapsible-content"> <ul><li><a href="/wiki/Electron_capture" title="Electron capture">electron</a> <ul><li><a href="/wiki/Double_electron_capture" title="Double electron capture">2×</a></li></ul></li> <li><a href="/wiki/Neutron_capture" title="Neutron capture">neutron</a> <ul><li><a href="/wiki/S-process" title="S-process">s</a></li> <li><a href="/wiki/R-process" title="R-process">r</a></li></ul></li> <li><a href="/wiki/Proton_capture" title="Proton capture">proton</a> <ul><li><a href="/wiki/P-process" title="P-process">p</a></li> <li><a href="/wiki/Rp-process" title="Rp-process">rp</a></li></ul></li></ul></div></div></td> </tr><tr><td class="sidebar-content hlist"> <div class="sidebar-list mw-collapsible mw-collapsed"><div class="sidebar-list-title" style="color: var(--color-base)">High-energy processes</div><div class="sidebar-list-content mw-collapsible-content"> <ul><li><a href="/wiki/Spallation" title="Spallation">Spallation</a> <ul><li><a href="/wiki/Cosmic_ray_spallation" title="Cosmic ray spallation">by cosmic ray</a></li></ul></li> <li><a href="/wiki/Photodisintegration" title="Photodisintegration">Photodisintegration</a></li></ul></div></div></td> </tr><tr><td class="sidebar-content hlist"> <div class="sidebar-list mw-collapsible mw-collapsed"><div class="sidebar-list-title" style="color: var(--color-base)"><a href="/wiki/Nucleosynthesis" title="Nucleosynthesis">Nucleosynthesis</a> and<br /> <a href="/wiki/Nuclear_astrophysics" title="Nuclear astrophysics">nuclear astrophysics</a></div><div class="sidebar-list-content mw-collapsible-content"> <ul><li><a href="/wiki/Nuclear_fusion" title="Nuclear fusion">Nuclear fusion</a></li></ul> <ul><li><small>Processes:</small> <ul><li><a href="/wiki/Stellar_nucleosynthesis" title="Stellar nucleosynthesis">Stellar</a></li> <li><a href="/wiki/Big_Bang_nucleosynthesis" title="Big Bang nucleosynthesis">Big Bang</a></li> <li><a href="/wiki/Supernova_nucleosynthesis" title="Supernova nucleosynthesis">Supernova</a></li></ul></li></ul> <ul><li>Nuclides: <ul><li><a href="/wiki/Primordial_nuclide" title="Primordial nuclide">Primordial</a></li> <li><a href="/wiki/Cosmogenic_nuclide" title="Cosmogenic nuclide">Cosmogenic</a></li> <li><a href="/wiki/Synthetic_element" title="Synthetic element">Artificial</a></li></ul></li></ul></div></div></td> </tr><tr><td class="sidebar-content hlist"> <div class="sidebar-list mw-collapsible mw-collapsed"><div class="sidebar-list-title" style="color: var(--color-base)"><a href="/wiki/High-energy_nuclear_physics" title="High-energy nuclear physics">High-energy nuclear physics</a></div><div class="sidebar-list-content mw-collapsible-content"> <ul><li><a href="/wiki/Quark%E2%80%93gluon_plasma" title="Quark–gluon plasma">Quark–gluon plasma</a></li> <li><a href="/wiki/Relativistic_Heavy_Ion_Collider" title="Relativistic Heavy Ion Collider">RHIC</a></li> <li><a href="/wiki/Large_Hadron_Collider" title="Large Hadron Collider">LHC</a></li></ul></div></div></td> </tr><tr><td class="sidebar-content hlist"> <div class="sidebar-list mw-collapsible mw-collapsed"><div class="sidebar-list-title" style="color: var(--color-base)"><a href="/wiki/Category:Nuclear_physicists" title="Category:Nuclear physicists">Scientists</a></div><div class="sidebar-list-content mw-collapsible-content"> <ul><li><a href="/wiki/Luis_Walter_Alvarez" title="Luis Walter Alvarez">Alvarez</a></li> <li><a href="/wiki/Henri_Becquerel" title="Henri Becquerel">Becquerel</a></li> <li><a href="/wiki/Hans_Bethe" title="Hans Bethe">Bethe</a></li> <li><a href="/wiki/Aage_Bohr" title="Aage Bohr">A. Bohr</a></li> <li><a href="/wiki/Niels_Bohr" title="Niels Bohr">N. Bohr</a></li> <li><a href="/wiki/James_Chadwick" title="James Chadwick">Chadwick</a></li> <li><a href="/wiki/John_Cockcroft" title="John Cockcroft">Cockcroft</a></li> <li><a href="/wiki/Ir%C3%A8ne_Joliot-Curie" title="Irène Joliot-Curie">Ir. Curie</a></li> <li><a href="/wiki/Fr%C3%A9d%C3%A9ric_Joliot-Curie" title="Frédéric Joliot-Curie">Fr. Curie</a></li> <li><a href="/wiki/Pierre_Curie" title="Pierre Curie">Pi. Curie</a></li> <li><a href="/wiki/Marie_Curie" title="Marie Curie">Skłodowska-Curie</a></li> <li><a href="/wiki/Clinton_Davisson" title="Clinton Davisson">Davisson</a></li> <li><a href="/wiki/Enrico_Fermi" title="Enrico Fermi">Fermi</a></li> <li><a href="/wiki/Otto_Hahn" title="Otto Hahn">Hahn</a></li> <li><a href="/wiki/J._Hans_D._Jensen" title="J. Hans D. Jensen">Jensen</a></li> <li><a href="/wiki/Ernest_Lawrence" title="Ernest Lawrence">Lawrence</a></li> <li><a href="/wiki/Maria_Goeppert-Mayer" class="mw-redirect" title="Maria Goeppert-Mayer">Mayer</a></li> <li><a href="/wiki/Lise_Meitner" title="Lise Meitner">Meitner</a></li> <li><a href="/wiki/Mark_Oliphant" title="Mark Oliphant">Oliphant</a></li> <li><a href="/wiki/J._Robert_Oppenheimer" title="J. Robert Oppenheimer">Oppenheimer</a></li> <li><a href="/wiki/Alexandru_Proca" title="Alexandru Proca">Proca</a></li> <li><a href="/wiki/Edward_Mills_Purcell" title="Edward Mills Purcell">Purcell</a></li> <li><a href="/wiki/Isidor_Isaac_Rabi" title="Isidor Isaac Rabi">Rabi</a></li> <li><a href="/wiki/Ernest_Rutherford" title="Ernest Rutherford">Rutherford</a></li> <li><a href="/wiki/Frederick_Soddy" title="Frederick Soddy">Soddy</a></li> <li><a href="/wiki/Fritz_Strassmann" title="Fritz Strassmann">Strassmann</a></li> <li><a href="/wiki/W%C5%82adys%C5%82aw_%C5%9Awi%C4%85tecki_(physicist)" title="Władysław Świątecki (physicist)">Świątecki</a></li> <li><a href="/wiki/Le%C3%B3_Szil%C3%A1rd" class="mw-redirect" title="Leó Szilárd">Szilárd</a></li> <li><a href="/wiki/Edward_Teller" title="Edward Teller">Teller</a></li> <li><a href="/wiki/J._J._Thomson" title="J. J. 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The fact that each isotope has one proton makes them all variants of <a href="/wiki/Hydrogen" title="Hydrogen">hydrogen</a>: the identity of the isotope is given by the number of protons and neutrons. From left to right, the isotopes are <a href="/wiki/Hydrogen" title="Hydrogen">protium</a> (<sup>1</sup>H) with zero neutrons, <a href="/wiki/Deuterium" title="Deuterium">deuterium</a> (<sup>2</sup>H) with one neutron, and <a href="/wiki/Tritium" title="Tritium">tritium</a> (<sup>3</sup>H) with two neutrons.</figcaption></figure> <p><b>Isotopes</b> are distinct nuclear species (or <i><a href="/wiki/Nuclide" title="Nuclide">nuclides</a></i>) of the same <a href="/wiki/Chemical_element" title="Chemical element">chemical element</a>. They have the same <a href="/wiki/Atomic_number" title="Atomic number">atomic number</a> (number of <a href="/wiki/Protons" class="mw-redirect" title="Protons">protons</a> in their <a href="/wiki/Atomic_nucleus" title="Atomic nucleus">nuclei</a>) and position in the <a href="/wiki/Periodic_table" title="Periodic table">periodic table</a> (and hence belong to the same chemical element), but different <a href="/wiki/Nucleon" title="Nucleon">nucleon</a> numbers (<a href="/wiki/Mass_number" title="Mass number">mass numbers</a>) due to different numbers of <a href="/wiki/Neutron" title="Neutron">neutrons</a> in their nuclei. While all isotopes of a given element have similar chemical properties, they have different <a href="/wiki/Atomic_mass" title="Atomic mass">atomic masses</a> and physical properties.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> </p><p>The term isotope is derived from the Greek roots isos (<a href="https://en.wiktionary.org/wiki/%E1%BC%B4%CF%83%CE%BF%CF%82" class="extiw" title="wikt:ἴσος">ἴσος</a> "equal") and topos (<a href="https://en.wiktionary.org/wiki/%CF%84%CF%8C%CF%80%CE%BF%CF%82" class="extiw" title="wikt:τόπος">τόπος</a> "place"), meaning "the same place"; thus, the meaning behind the name is that different isotopes of a single element occupy the same position on the <a href="/wiki/Periodic_table" title="Periodic table">periodic table</a>.<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> It was coined by Scottish doctor and writer <a href="/wiki/Margaret_Todd_(doctor)" title="Margaret Todd (doctor)">Margaret Todd</a> in a 1913 suggestion to the British chemist <a href="/wiki/Frederick_Soddy" title="Frederick Soddy">Frederick Soddy</a>, who popularized the term.<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> </p><p>The number of protons within the <a href="/wiki/Atomic_nucleus" title="Atomic nucleus">atom's nucleus</a> is called its <a href="/wiki/Atomic_number" title="Atomic number">atomic number</a> and is equal to the number of <a href="/wiki/Electron" title="Electron">electrons</a> in the neutral (non-ionized) atom. Each atomic number identifies a specific element, but not the isotope; an atom of a given element may have a wide range in its number of <a href="/wiki/Neutron" title="Neutron">neutrons</a>. The number of <a href="/wiki/Nucleon" title="Nucleon">nucleons</a> (both protons and neutrons) in the nucleus is the atom's <a href="/wiki/Mass_number" title="Mass number">mass number</a>, and each isotope of a given element has a different mass number. </p><p>For example, <a href="/wiki/Carbon-12" title="Carbon-12">carbon-12</a>, <a href="/wiki/Carbon-13" title="Carbon-13">carbon-13</a>, and <a href="/wiki/Carbon-14" title="Carbon-14">carbon-14</a> are three isotopes of the element <a href="/wiki/Carbon" title="Carbon">carbon</a> with mass numbers 12, 13, and 14, respectively. The atomic number of carbon is 6, which means that every carbon atom has 6 protons so that the neutron numbers of these isotopes are 6, 7, and 8 respectively. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Isotope_vs._nuclide">Isotope vs. nuclide</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=1" title="Edit section: Isotope vs. nuclide"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>A <a href="/wiki/Nuclide" title="Nuclide">nuclide</a> is a species of an atom with a specific number of protons and neutrons in the nucleus, for example, carbon-13 with 6 protons and 7 neutrons. The <i>nuclide</i> concept (referring to individual nuclear species) emphasizes nuclear properties over chemical properties, whereas the <i>isotope</i> concept (grouping all atoms of each element) emphasizes <a href="/wiki/Chemistry" title="Chemistry">chemical</a> over nuclear. The neutron number greatly affects nuclear properties, but its effect on chemical properties is negligible for most elements. Even for the lightest elements, whose ratio of neutron number to atomic number varies the most between isotopes, it usually has only a small effect although it matters in some circumstances (for hydrogen, the lightest element, the isotope effect is large enough to affect biology strongly). The term <i>isotopes</i> (originally also <i>isotopic elements</i>,<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> now sometimes <i>isotopic nuclides</i><sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup>) is intended to imply comparison (like <i><a href="/wiki/Synonym" title="Synonym">synonyms</a></i> or <i><a href="/wiki/Isomer" title="Isomer">isomers</a></i>). For example, the nuclides <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">12</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">6</sub></span></span>C<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>, <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">13</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">6</sub></span></span>C<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>, <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">14</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">6</sub></span></span>C<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span> are isotopes (nuclides with the same atomic number but different mass numbers<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup>), but <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">40</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">18</sub></span></span>Ar<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>, <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">40</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">19</sub></span></span>K<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>, <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">40</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">20</sub></span></span>Ca<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span> are <a href="/wiki/Isobar_(nuclide)" title="Isobar (nuclide)">isobars</a> (nuclides with the same mass number<sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup>). However, <i>isotope</i> is the older term and so is better known than <i>nuclide</i> and is still sometimes used in contexts in which <i>nuclide</i> might be more appropriate, such as <a href="/wiki/Nuclear_technology" title="Nuclear technology">nuclear technology</a> and <a href="/wiki/Nuclear_medicine" title="Nuclear medicine">nuclear medicine</a>. </p> <div class="mw-heading mw-heading2"><h2 id="Notation">Notation</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=2" title="Edit section: Notation"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>An isotope and/or nuclide is specified by the name of the particular element (this indicates the atomic number) followed by a hyphen and the mass number (e.g. <a href="/wiki/Helium-3" title="Helium-3">helium-3</a>, <a href="/wiki/Helium-4" title="Helium-4">helium-4</a>, <a href="/wiki/Carbon-12" title="Carbon-12">carbon-12</a>, <a href="/wiki/Carbon-14" title="Carbon-14">carbon-14</a>, <a href="/wiki/Uranium-235" title="Uranium-235">uranium-235</a> and <a href="/wiki/Uranium-239" class="mw-redirect" title="Uranium-239">uranium-239</a>).<sup id="cite_ref-8" class="reference"><a href="#cite_note-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> When a <a href="/wiki/Chemical_symbol" title="Chemical symbol">chemical symbol</a> is used, e.g. "C" for carbon, standard notation (now known as "AZE notation" because <i>A</i> is the <a href="/wiki/Mass_number" title="Mass number">mass number</a>, <i>Z</i> the <a href="/wiki/Atomic_number" title="Atomic number">atomic number</a>, and E for <a href="/wiki/Chemical_element" title="Chemical element">element</a>) is to indicate the mass number (number of nucleons) with a <a href="/wiki/Superscript" class="mw-redirect" title="Superscript">superscript</a> at the upper left of the chemical symbol and to indicate the atomic number with a <a href="/wiki/Subscript" class="mw-redirect" title="Subscript">subscript</a> at the lower left (e.g. <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">3</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">2</sub></span></span>He<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>, <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">4</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">2</sub></span></span>He<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>, <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">12</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">6</sub></span></span>C<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>, <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">14</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">6</sub></span></span>C<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>, <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">235</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">92</sub></span></span>U<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>, and <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">239</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">92</sub></span></span>U<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>).<sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> Because the atomic number is given by the element symbol, it is common to state only the mass number in the superscript and leave out the atomic number subscript (e.g. <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">3</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span>He<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>, <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">4</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span>He<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>, <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">12</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span>C<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>, <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">14</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span>C<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>, <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">235</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span>U<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>, and <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">239</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span>U<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>). The letter <i>m</i> (for metastable) is sometimes appended after the mass number to indicate a <a href="/wiki/Nuclear_isomer" title="Nuclear isomer">nuclear isomer</a>, a <a href="/wiki/Metastable" class="mw-redirect" title="Metastable">metastable</a> or energetically excited nuclear state (as opposed to the lowest-energy <a href="/wiki/Ground_state" title="Ground state">ground state</a>), for example <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">180m</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">73</sub></span></span>Ta<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span> (<a href="/wiki/Tantalum-180m" class="mw-redirect" title="Tantalum-180m">tantalum-180m</a>). </p><p>The common pronunciation of the AZE notation is different from how it is written: <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">4</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">2</sub></span></span>He<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span> is commonly pronounced as helium-four instead of four-two-helium, and <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">235</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">92</sub></span></span>U<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span> as uranium two-thirty-five (American English) or uranium-two-three-five (British) instead of 235-92-uranium. </p> <div class="mw-heading mw-heading2"><h2 id="Radioactive,_primordial,_and_stable_isotopes"><span id="Radioactive.2C_primordial.2C_and_stable_isotopes"></span>Radioactive, primordial, and stable isotopes</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=3" title="Edit section: Radioactive, primordial, and stable isotopes"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Some isotopes/nuclides are <a href="/wiki/Radioactive" class="mw-redirect" title="Radioactive">radioactive</a>, and are therefore referred to as radioisotopes or <a href="/wiki/Radionuclide" title="Radionuclide">radionuclides</a>, whereas others have never been observed to decay radioactively and are referred to as stable isotopes or <a href="/wiki/Stable_nuclide" title="Stable nuclide">stable nuclides</a>. For example, <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">14</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span>C<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span> is a radioactive form of carbon, whereas <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">12</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span>C<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span> and <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">13</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span>C<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span> are stable isotopes. There are about 339 naturally occurring nuclides on Earth,<sup id="cite_ref-lindsay_11-0" class="reference"><a href="#cite_note-lindsay-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> of which 286 are <a href="/wiki/Primordial_nuclide" title="Primordial nuclide">primordial nuclides</a>, meaning that they have existed since the <a href="/wiki/Solar_System" title="Solar System">Solar System</a>'s formation. </p><p>Primordial nuclides include 35 nuclides with very long <a href="/wiki/Half-life" title="Half-life">half-lives</a> (over 100 million years) and 251 that are formally considered as "<a href="/wiki/Stable_nuclide" title="Stable nuclide">stable nuclides</a>",<sup id="cite_ref-lindsay_11-1" class="reference"><a href="#cite_note-lindsay-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> because they have not been observed to decay. In most cases, for obvious reasons, if an element has stable isotopes, those isotopes predominate in the elemental abundance found on Earth and in the Solar System. However, in the cases of three elements (<a href="/wiki/Tellurium" title="Tellurium">tellurium</a>, <a href="/wiki/Indium" title="Indium">indium</a>, and <a href="/wiki/Rhenium" title="Rhenium">rhenium</a>) the most abundant isotope found in nature is actually one (or two) extremely long-lived radioisotope(s) of the element, despite these elements having one or more stable isotopes. </p><p>Theory predicts that many apparently "stable" nuclides are radioactive, with extremely long half-lives (discounting the possibility of <a href="/wiki/Proton_decay" title="Proton decay">proton decay</a>, which would make all nuclides ultimately unstable). Some stable nuclides are in theory energetically susceptible to other known forms of decay, such as alpha decay or double beta decay, but no decay products have yet been observed, and so these isotopes are said to be "observationally stable". The predicted half-lives for these nuclides often greatly exceed the estimated age of the universe, and in fact, there are also 31 known radionuclides (see <a href="/wiki/Primordial_nuclide" title="Primordial nuclide">primordial nuclide</a>) with half-lives longer than the age of the universe. </p><p>Adding in the radioactive nuclides that have been created artificially, there are <a href="/wiki/List_of_nuclides" title="List of nuclides">3,339 currently known nuclides</a>.<sup id="cite_ref-12" class="reference"><a href="#cite_note-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> These include 905 nuclides that are either stable or have half-lives longer than 60 minutes. See <a href="/wiki/List_of_nuclides" title="List of nuclides">list of nuclides</a> for details. </p> <div class="mw-heading mw-heading2"><h2 id="History">History</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=4" title="Edit section: History"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading3"><h3 id="Radioactive_isotopes">Radioactive isotopes</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=5" title="Edit section: Radioactive isotopes"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The existence of isotopes was first suggested in 1913 by the <a href="/wiki/Radiochemistry" title="Radiochemistry">radiochemist</a> <a href="/wiki/Frederick_Soddy" title="Frederick Soddy">Frederick Soddy</a>, based on studies of radioactive <a href="/wiki/Decay_chain" title="Decay chain">decay chains</a> that indicated about 40 different species referred to as <i>radioelements</i> (i.e. radioactive elements) between uranium and lead, although the periodic table only allowed for 11 elements between lead and uranium inclusive.<sup id="cite_ref-13" class="reference"><a href="#cite_note-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-14" class="reference"><a href="#cite_note-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-ley196610_15-0" class="reference"><a href="#cite_note-ley196610-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> </p><p>Several attempts to separate these new radioelements chemically had failed.<sup id="cite_ref-Scerri_16-0" class="reference"><a href="#cite_note-Scerri-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> For example, Soddy had shown in 1910 that <a href="/wiki/Mesothorium" class="mw-redirect" title="Mesothorium">mesothorium</a> (later shown to be <sup>228</sup>Ra), <a href="/wiki/Radium" title="Radium">radium</a> (<sup>226</sup>Ra, the longest-lived isotope), and <a href="/wiki/Isotopes_of_radium" title="Isotopes of radium">thorium X</a> (<sup>224</sup>Ra) are impossible to separate.<sup id="cite_ref-Nagel_17-0" class="reference"><a href="#cite_note-Nagel-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup> Attempts to place the radioelements in the periodic table led Soddy and <a href="/wiki/Kazimierz_Fajans" title="Kazimierz Fajans">Kazimierz Fajans</a> independently to propose their <a href="/wiki/Radioactive_displacement_law_of_Fajans_and_Soddy" title="Radioactive displacement law of Fajans and Soddy">radioactive displacement law</a> in 1913, to the effect that <a href="/wiki/Alpha_decay" title="Alpha decay">alpha decay</a> produced an element two places to the left in the periodic table, whereas <a href="/wiki/Beta_decay" title="Beta decay">beta decay</a> emission produced an element one place to the right.<sup id="cite_ref-18" class="reference"><a href="#cite_note-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-19" class="reference"><a href="#cite_note-19"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-20" class="reference"><a href="#cite_note-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-21" class="reference"><a href="#cite_note-21"><span class="cite-bracket">[</span>21<span class="cite-bracket">]</span></a></sup> Soddy recognized that emission of an alpha particle followed by two beta particles led to the formation of an element chemically identical to the initial element but with a mass four units lighter and with different radioactive properties. </p><p>Soddy proposed that several types of atoms (differing in radioactive properties) could occupy the same place in the table.<sup id="cite_ref-ley196610_15-1" class="reference"><a href="#cite_note-ley196610-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> For example, the alpha-decay of uranium-235 forms thorium-231, whereas the beta decay of actinium-230 forms thorium-230.<sup id="cite_ref-Scerri_16-1" class="reference"><a href="#cite_note-Scerri-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> The term "isotope", Greek for "at the same place",<sup id="cite_ref-ley196610_15-2" class="reference"><a href="#cite_note-ley196610-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> was suggested to Soddy by <a href="/wiki/Margaret_Todd_(doctor)" title="Margaret Todd (doctor)">Margaret Todd</a>, a Scottish physician and family friend, during a conversation in which he explained his ideas to her.<sup id="cite_ref-Nagel_17-1" class="reference"><a href="#cite_note-Nagel-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-22" class="reference"><a href="#cite_note-22"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-23" class="reference"><a href="#cite_note-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-pmid16134128_24-0" class="reference"><a href="#cite_note-pmid16134128-24"><span class="cite-bracket">[</span>24<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-25" class="reference"><a href="#cite_note-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-26" class="reference"><a href="#cite_note-26"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup> He received the 1921 <a href="/wiki/Nobel_Prize_in_Chemistry" title="Nobel Prize in Chemistry">Nobel Prize in Chemistry</a> in part for his work on isotopes.<sup id="cite_ref-soddynobel_27-0" class="reference"><a href="#cite_note-soddynobel-27"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup> </p> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Discovery_of_neon_isotopes.JPG" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Discovery_of_neon_isotopes.JPG/220px-Discovery_of_neon_isotopes.JPG" decoding="async" width="220" height="271" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Discovery_of_neon_isotopes.JPG/330px-Discovery_of_neon_isotopes.JPG 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Discovery_of_neon_isotopes.JPG/440px-Discovery_of_neon_isotopes.JPG 2x" data-file-width="2036" data-file-height="2511" /></a><figcaption>In the bottom right corner of <a href="/wiki/J._J._Thomson" title="J. J. Thomson">J. J. Thomson</a>'s photographic plate are the separate impact marks for the two isotopes of <a href="/wiki/Neon" title="Neon">neon</a>: neon-20 and neon-22.</figcaption></figure> <p>In 1914 <a href="/wiki/Theodore_William_Richards" title="Theodore William Richards">T. W. Richards</a> found variations between the atomic weight of lead from different mineral sources, attributable to variations in isotopic composition due to different radioactive origins.<sup id="cite_ref-Scerri_16-2" class="reference"><a href="#cite_note-Scerri-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-soddynobel_27-1" class="reference"><a href="#cite_note-soddynobel-27"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Stable_isotopes">Stable isotopes</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=6" title="Edit section: Stable isotopes"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The first evidence for multiple isotopes of a stable (non-radioactive) element was found by <a href="/wiki/J._J._Thomson" title="J. J. Thomson">J. J. Thomson</a> in 1912 as part of his exploration into the composition of <a href="/wiki/Canal_rays" class="mw-redirect" title="Canal rays">canal rays</a> (positive ions).<sup id="cite_ref-28" class="reference"><a href="#cite_note-28"><span class="cite-bracket">[</span>28<span class="cite-bracket">]</span></a></sup> Thomson channelled streams of <a href="/wiki/Neon" title="Neon">neon</a> ions through parallel magnetic and electric fields, measured their deflection by placing a photographic plate in their path, and computed their mass to charge ratio using a method that became known as the Thomson's parabola method. Each stream created a glowing patch on the plate at the point it struck. Thomson observed two separate parabolic patches of light on the photographic plate (see image), which suggested two species of nuclei with different mass-to-charge ratios. He wrote "There can, therefore, I think, be little doubt that what has been called neon is not a simple gas but a mixture of two gases, one of which has an atomic weight about 20 and the other about 22. The parabola due to the heavier gas is always much fainter than that due to the lighter, so that probably the heavier gas forms only a small percentage of the mixture."<sup id="cite_ref-29" class="reference"><a href="#cite_note-29"><span class="cite-bracket">[</span>29<span class="cite-bracket">]</span></a></sup> </p><p><a href="/wiki/Francis_William_Aston" title="Francis William Aston">F. W. Aston</a> subsequently discovered multiple stable isotopes for numerous elements using a <a href="/wiki/Mass_spectrograph" class="mw-redirect" title="Mass spectrograph">mass spectrograph</a>. In 1919 Aston studied neon with sufficient <a href="/wiki/Resolution_(mass_spectrometry)" title="Resolution (mass spectrometry)">resolution</a> to show that the two isotopic masses are very close to the integers 20 and 22 and that neither is equal to the known molar mass (20.2) of neon gas. This is an example of Aston's <a href="/wiki/Whole_number_rule" title="Whole number rule">whole number rule</a> for isotopic masses, which states that large deviations of elemental molar masses from integers are primarily due to the fact that the element is a mixture of isotopes. Aston similarly showed in 1920 that the molar mass of <a href="/wiki/Chlorine" title="Chlorine">chlorine</a> (35.45) is a weighted average of the almost integral masses for the two isotopes <sup>35</sup>Cl and <sup>37</sup>Cl.<sup id="cite_ref-30" class="reference"><a href="#cite_note-30"><span class="cite-bracket">[</span>30<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-31" class="reference"><a href="#cite_note-31"><span class="cite-bracket">[</span>31<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Neutrons">Neutrons</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=7" title="Edit section: Neutrons"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>After the <a href="/wiki/Discovery_of_the_neutron" title="Discovery of the neutron">discovery of the neutron</a> by <a href="/wiki/James_Chadwick" title="James Chadwick">James Chadwick</a> in 1932,<sup id="cite_ref-Neutron_32-0" class="reference"><a href="#cite_note-Neutron-32"><span class="cite-bracket">[</span>32<span class="cite-bracket">]</span></a></sup> the ultimate root cause for the existence of isotopes was clarified, that is, the nuclei of different isotopes for a given element have different numbers of neutrons, albeit having the same number of protons. </p> <div class="mw-heading mw-heading2"><h2 id="Variation_in_properties_between_isotopes">Variation in properties between isotopes</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=8" title="Edit section: Variation in properties between isotopes"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading3"><h3 id="Chemical_and_molecular_properties">Chemical and molecular properties</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=9" title="Edit section: Chemical and molecular properties"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>A neutral atom has the same number of electrons as protons. Thus different isotopes of a given element all have the same number of electrons and share a similar electronic structure. Because the chemical behaviour of an atom is largely determined by its electronic structure, different isotopes exhibit nearly identical chemical behaviour. </p><p>The main exception to this is the <a href="/wiki/Kinetic_isotope_effect" title="Kinetic isotope effect">kinetic isotope effect</a>: due to their larger masses, heavier isotopes tend to react somewhat more slowly than lighter isotopes of the same element. This is most pronounced by far for <a href="/wiki/Hydrogen-1" class="mw-redirect" title="Hydrogen-1">protium</a> (<span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">1</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span>H<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>), <a href="/wiki/Deuterium" title="Deuterium">deuterium</a> (<span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">2</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span>H<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>), and <a href="/wiki/Tritium" title="Tritium">tritium</a> (<span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">3</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span>H<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>), because deuterium has twice the mass of protium and tritium has three times the mass of protium.<sup id="cite_ref-33" class="reference"><a href="#cite_note-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> These mass differences also affect the behavior of their respective chemical bonds, by changing the center of gravity (<a href="/wiki/Reduced_mass" title="Reduced mass">reduced mass</a>) of the atomic systems. However, for heavier elements, the relative mass difference between isotopes is much less so that the mass-difference effects on chemistry are usually negligible. (Heavy elements also have relatively more neutrons than lighter elements, so the ratio of the nuclear mass to the collective electronic mass is slightly greater.) There is also an <a href="/wiki/Equilibrium_constant#Effect_of_isotopic_substitution" title="Equilibrium constant">equilibrium isotope effect</a>. </p> <figure class="mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Isotopes_and_half-life.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/8/80/Isotopes_and_half-life.svg/288px-Isotopes_and_half-life.svg.png" decoding="async" width="288" height="346" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/8/80/Isotopes_and_half-life.svg/432px-Isotopes_and_half-life.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/8/80/Isotopes_and_half-life.svg/577px-Isotopes_and_half-life.svg.png 2x" data-file-width="640" data-file-height="768" /></a><figcaption>Isotope half-lives. <i>Z</i> = number of protons. <i>N</i> = number of neutrons. The plot for stable isotopes diverges from the line <i>Z</i> = <i>N</i> as the element number <i>Z</i> becomes larger</figcaption></figure> <p>Similarly, two <a href="/wiki/Molecules" class="mw-redirect" title="Molecules">molecules</a> that differ only in the isotopes of their atoms (<a href="/wiki/Isotopologue" title="Isotopologue">isotopologues</a>) have identical electronic structures, and therefore almost indistinguishable physical and chemical properties (again with deuterium and tritium being the primary exceptions). The <i>vibrational modes</i> of a molecule are determined by its shape and by the masses of its constituent atoms; so different isotopologues have different sets of vibrational modes. Because vibrational modes allow a molecule to absorb <a href="/wiki/Photon" title="Photon">photons</a> of corresponding energies, isotopologues have different optical properties in the <a href="/wiki/Infrared" title="Infrared">infrared</a> range. </p> <div class="mw-heading mw-heading3"><h3 id="Nuclear_properties_and_stability">Nuclear properties and stability</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=10" title="Edit section: Nuclear properties and stability"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">See also: <a href="/wiki/Stable_nuclide" title="Stable nuclide">Stable nuclide</a>, <a href="/wiki/Stable_isotope_ratio" title="Stable isotope ratio">Stable isotope ratio</a>, <a href="/wiki/List_of_nuclides" title="List of nuclides">List of nuclides</a>, and <a href="/wiki/List_of_elements_by_stability_of_isotopes" title="List of elements by stability of isotopes">List of elements by stability of isotopes</a></div> <p>Atomic nuclei consist of protons and neutrons bound together by the <a href="/wiki/Residual_strong_force" class="mw-redirect" title="Residual strong force">residual strong force</a>. Because protons are positively charged, they repel each other. Neutrons, which are electrically neutral, stabilize the nucleus in two ways. Their copresence pushes protons slightly apart, reducing the electrostatic repulsion between the protons, and they exert an attractive nuclear force on each other and on protons. For this reason, one or more neutrons are necessary for two or more protons to bind into a nucleus. As the number of protons increases, so does the ratio of neutrons to protons necessary to ensure a stable nucleus (see graph at right). For example, although the neutron:proton ratio of <span style="white-space:nowrap;"><a href="/wiki/He-3" class="mw-redirect" title="He-3"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">3</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">2</sub></span></span>He<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span> is 1:2, the neutron:proton ratio of <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">238</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">92</sub></span></span>U<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span> is greater than 3:2. A number of lighter elements have stable nuclides with the ratio 1:1 (<i>Z</i> = <i>N</i>). The nuclide <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">40</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">20</sub></span></span>Ca<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span> (calcium-40) is observationally the heaviest stable nuclide with the same number of neutrons and protons. All stable nuclides heavier than calcium-40 contain more neutrons than protons. </p> <div class="mw-heading mw-heading3"><h3 id="Numbers_of_isotopes_per_element">Numbers of isotopes per element</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=11" title="Edit section: Numbers of isotopes per element"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Of the 80 elements with a stable isotope, the largest number of stable isotopes observed for any element is ten (for the element <a href="/wiki/Tin" title="Tin">tin</a>). No element has nine or eight stable isotopes. Five elements have seven stable isotopes, eight have six stable isotopes, ten have five stable isotopes, nine have four stable isotopes, five have three stable isotopes, 16 have two stable isotopes (counting <span style="white-space:nowrap;"><a href="/wiki/Ta-180m" class="mw-redirect" title="Ta-180m"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">180m</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">73</sub></span></span>Ta<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span> as stable), and 26 elements have only a single stable isotope (of these, 19 are so-called <a href="/wiki/Mononuclidic_element" title="Mononuclidic element">mononuclidic elements</a>, having a single primordial stable isotope that dominates and fixes the atomic weight of the natural element to high precision; 3 radioactive mononuclidic elements occur as well).<sup id="cite_ref-nuclidetable_34-0" class="reference"><a href="#cite_note-nuclidetable-34"><span class="cite-bracket">[</span>34<span class="cite-bracket">]</span></a></sup> In total, there are 251 nuclides that have not been observed to decay. For the 80 elements that have one or more stable isotopes, the average number of stable isotopes is 251/80 ≈ 3.14 isotopes per element. </p> <div class="mw-heading mw-heading3"><h3 id="Even_and_odd_nucleon_numbers">Even and odd nucleon numbers</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=12" title="Edit section: Even and odd nucleon numbers"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Even_and_odd_atomic_nuclei" title="Even and odd atomic nuclei">Even and odd atomic nuclei</a></div> <table class="wikitable" style="float:right; text-align:right; margin-left:1em;"> <caption>Even/odd <i>Z</i>, <i>N</i> (<a href="/wiki/Parity_of_zero" title="Parity of zero"><span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">1</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span>H<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span> as OE</a>) </caption> <tbody><tr> <th>p, n</th> <th>EE</th> <th>OO</th> <th>EO</th> <th>OE</th> <th>Total </th></tr> <tr> <td>Stable</td> <td>145</td> <td>5</td> <td>53</td> <td>48</td> <td>251 </td></tr> <tr> <td>Long-lived</td> <td>23</td> <td>4</td> <td>3</td> <td>5</td> <td>35 </td></tr> <tr> <td>All primordial</td> <td>168</td> <td>9</td> <td>56</td> <td>53</td> <td>286 </td></tr></tbody></table> <p>The proton:neutron ratio is not the only factor affecting nuclear stability. It depends also on evenness or oddness of its atomic number <i>Z</i>, neutron number <i>N</i> and, consequently, of their sum, the mass number <i>A</i>. Oddness of both <i>Z</i> and <i>N</i> tends to lower the <a href="/wiki/Nuclear_binding_energy" title="Nuclear binding energy">nuclear binding energy</a>, making odd nuclei, generally, less stable. This remarkable difference of nuclear binding energy between neighbouring nuclei, especially of odd-<i>A</i> <a href="/wiki/Isobar_(nuclide)" title="Isobar (nuclide)">isobars</a>, has important consequences: unstable isotopes with a nonoptimal number of neutrons or protons decay by <a href="/wiki/Beta_decay" title="Beta decay">beta decay</a> (including <a href="/wiki/Positron_emission" title="Positron emission">positron emission</a>), <a href="/wiki/Electron_capture" title="Electron capture">electron capture</a>, or other less common decay modes such as <a href="/wiki/Spontaneous_fission" title="Spontaneous fission">spontaneous fission</a> and <a href="/wiki/Cluster_decay" title="Cluster decay">cluster decay</a>. </p><p>Most stable nuclides are even-proton-even-neutron, where all numbers <i>Z</i>, <i>N</i>, and <i>A</i> are even. The odd-<i>A</i> stable nuclides are divided (roughly evenly) into odd-proton-even-neutron, and even-proton-odd-neutron nuclides. Stable odd-proton-odd-neutron nuclides are the least common. </p> <div class="mw-heading mw-heading4"><h4 id="Even_atomic_number">Even atomic number</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=13" title="Edit section: Even atomic number"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The 146 even-proton, even-neutron (EE) nuclides comprise ~58% of all stable nuclides and all have <a href="/wiki/Spin_(physics)" title="Spin (physics)">spin</a> 0 because of pairing. There are also 24 primordial long-lived even-even nuclides. As a result, each of the 41 even-numbered elements from 2 to 82 has <a href="/wiki/List_of_elements_by_stability_of_isotopes" title="List of elements by stability of isotopes">at least one stable isotope</a>, and most of these elements have <i>several</i> primordial isotopes. Half of these even-numbered elements have six or more stable isotopes. The extreme stability of <a href="/wiki/Helium-4" title="Helium-4">helium-4</a> due to a double <a href="/wiki/Semi-empirical_mass_formula#Pairing_term" title="Semi-empirical mass formula">pairing</a> of 2 protons and 2 neutrons prevents <i>any</i> nuclides containing five (<span style="white-space:nowrap;"><a href="/wiki/Helium-5" class="mw-redirect" title="Helium-5"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">5</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">2</sub></span></span>He<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span>, <span style="white-space:nowrap;"><a href="/wiki/Lithium-5" class="mw-redirect" title="Lithium-5"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">5</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">3</sub></span></span>Li<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span>) or eight (<span style="white-space:nowrap;"><a href="/wiki/Beryllium-8" title="Beryllium-8"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">8</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">4</sub></span></span>Be<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span>) nucleons from existing long enough to serve as platforms for the buildup of heavier elements via <a href="/wiki/Nuclear_fusion" title="Nuclear fusion">nuclear fusion</a> in stars (see <a href="/wiki/Triple_alpha_process" class="mw-redirect" title="Triple alpha process">triple alpha process</a>). </p> <table class="wikitable" style="float:right; margin-left:1em;"> <caption>Even-odd long-lived </caption> <tbody><tr> <th></th> <th><a href="/wiki/Decay_mode" class="mw-redirect" title="Decay mode">Decay</a></th> <th><a href="/wiki/Half-life" title="Half-life">Half-life</a> </th></tr> <tr> <td><span style="white-space:nowrap;"><a href="/wiki/Cadmium-113" class="mw-redirect" title="Cadmium-113"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">113</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">48</sub></span></span>Cd<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span></td> <td><a href="/wiki/Beta_decay" title="Beta decay">beta</a> </td> <td style="text-align:right;">7.7<span style="margin:0 .15em 0 .25em">×</span>10<sup><span class="nowrap"><span data-sort-value="7001150000000000000♠"></span>15</span></sup> <a href="/wiki/Annum" class="mw-redirect" title="Annum">a</a> </td></tr> <tr> <td><span style="white-space:nowrap;"><a href="/wiki/Samarium-147" title="Samarium-147"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">147</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">62</sub></span></span>Sm<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span></td> <td><a href="/wiki/Alpha_decay" title="Alpha decay">alpha</a> </td> <td style="text-align:right;">1.06<span style="margin:0 .15em 0 .25em">×</span>10<sup><span class="nowrap"><span data-sort-value="7001110000000000000♠"></span>11</span></sup> <a href="/wiki/Annum" class="mw-redirect" title="Annum">a</a> </td></tr> <tr> <td><span style="white-space:nowrap;"><a href="/wiki/Uranium-235" title="Uranium-235"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">235</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">92</sub></span></span>U<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span></td> <td><a href="/wiki/Alpha_decay" title="Alpha decay">alpha</a> </td> <td style="text-align:right;">7.04<span style="margin:0 .15em 0 .25em">×</span>10<sup><span class="nowrap"><span data-sort-value="7000800000000000000♠"></span>8</span></sup> <a href="/wiki/Annum" class="mw-redirect" title="Annum">a</a> </td></tr></tbody></table> <p>Only five stable nuclides contain both an odd number of protons <i>and</i> an odd number of neutrons. The first four "odd-odd" nuclides occur in low mass nuclides, for which changing a proton to a neutron or vice versa would lead to a very lopsided <a href="/wiki/Proton-neutron_ratio" class="mw-redirect" title="Proton-neutron ratio">proton-neutron ratio</a> (<span style="white-space:nowrap;"><a href="/wiki/Hydrogen-2" class="mw-redirect" title="Hydrogen-2"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">2</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">1</sub></span></span>H<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span>, <span style="white-space:nowrap;"><a href="/wiki/Lithium-6" class="mw-redirect" title="Lithium-6"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">6</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">3</sub></span></span>Li<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span>, <span style="white-space:nowrap;"><a href="/wiki/Boron-10" class="mw-redirect" title="Boron-10"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">10</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">5</sub></span></span>B<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span>, and <span style="white-space:nowrap;"><a href="/wiki/Nitrogen-14" class="mw-redirect" title="Nitrogen-14"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">14</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">7</sub></span></span>N<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span>; spins 1, 1, 3, 1). The only other entirely "stable" odd-odd nuclide, <span style="white-space:nowrap;"><a href="/wiki/Tantalum-180m" class="mw-redirect" title="Tantalum-180m"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">180m</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">73</sub></span></span>Ta<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span> (spin 9), is thought to be the rarest of the 251 stable nuclides, and is the only primordial <a href="/wiki/Nuclear_isomer" title="Nuclear isomer">nuclear isomer</a>, which has not yet been observed to decay despite experimental attempts.<sup id="cite_ref-35" class="reference"><a href="#cite_note-35"><span class="cite-bracket">[</span>35<span class="cite-bracket">]</span></a></sup> </p><p>Many odd-odd radionuclides (such as the ground state of tantalum-180) with comparatively short half-lives are known. Usually, they beta-decay to their nearby even-even <a href="/wiki/Isobar_(nuclide)" title="Isobar (nuclide)">isobars</a> that have paired protons and paired neutrons. Of the nine primordial odd-odd nuclides (five stable and four radioactive with long half-lives), only <span style="white-space:nowrap;"><a href="/wiki/Nitrogen-14" class="mw-redirect" title="Nitrogen-14"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">14</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">7</sub></span></span>N<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span> is the most common isotope of a common element. This is the case because it is a part of the <a href="/wiki/CNO_cycle" title="CNO cycle">CNO cycle</a>. The nuclides <span style="white-space:nowrap;"><a href="/wiki/Lithium-6" class="mw-redirect" title="Lithium-6"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">6</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">3</sub></span></span>Li<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span> and <span style="white-space:nowrap;"><a href="/wiki/Boron-10" class="mw-redirect" title="Boron-10"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">10</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">5</sub></span></span>B<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span> are minority isotopes of elements that are themselves rare compared to other light elements, whereas the other six isotopes make up only a tiny percentage of the natural abundance of their elements. </p> <div class="mw-heading mw-heading4"><h4 id="Odd_atomic_number">Odd atomic number</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=14" title="Edit section: Odd atomic number"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>53 stable nuclides have an even number of protons and an odd number of neutrons. They are a minority in comparison to the even-even isotopes, which are about 3 times as numerous. Among the 41 even-<i>Z</i> elements that have a stable nuclide, only two elements (argon and cerium) have no even-odd stable nuclides. One element (tin) has three. There are 24 elements that have one even-odd nuclide and 13 that have two odd-even nuclides. Of 35 primordial radionuclides there exist four even-odd nuclides (see table at right), including the <a href="/wiki/Fissile" class="mw-redirect" title="Fissile">fissile</a> <span style="white-space:nowrap;"><a href="/wiki/Uranium-235" title="Uranium-235"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">235</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">92</sub></span></span>U<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span>. Because of their odd neutron numbers, the even-odd nuclides tend to have large <a href="/wiki/Neutron_capture" title="Neutron capture">neutron capture</a> cross-sections, due to the energy that results from neutron-pairing effects. These stable even-proton odd-neutron nuclides tend to be uncommon by abundance in nature, generally because, to form and enter into primordial abundance, they must have escaped capturing neutrons to form yet other stable even-even isotopes, during both the <a href="/wiki/S-process" title="S-process">s-process</a> and <a href="/wiki/R-process" title="R-process">r-process</a> of neutron capture, during <a href="/wiki/Stellar_nucleosynthesis" title="Stellar nucleosynthesis">nucleosynthesis in stars</a>. For this reason, only <span style="white-space:nowrap;"><a href="/wiki/Platinum-195" class="mw-redirect" title="Platinum-195"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">195</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">78</sub></span></span>Pt<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span> and <span style="white-space:nowrap;"><a href="/wiki/Beryllium-9" class="mw-redirect" title="Beryllium-9"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">9</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">4</sub></span></span>Be<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span> are the most naturally abundant isotopes of their element. </p><p>48 stable odd-proton-even-neutron nuclides, stabilized by their paired neutrons, form most of the stable isotopes of the odd-numbered elements; the very few odd-proton-odd-neutron nuclides comprise the others. There are 41 odd-numbered elements with <i>Z</i> = 1 through 81, of which 39 have stable isotopes (<a href="/wiki/Technetium" title="Technetium">technetium</a> (<span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">43</sub></span></span>Tc<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>) and <a href="/wiki/Promethium" title="Promethium">promethium</a> (<span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">61</sub></span></span>Pm<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>) have no stable isotopes). Of these 39 odd <i>Z</i> elements, 30 elements (including hydrogen-1 where 0 neutrons is <a href="/wiki/Parity_of_zero" title="Parity of zero">even</a>) have one stable odd-even isotope, and nine elements: <a href="/wiki/Chlorine" title="Chlorine">chlorine</a> (<span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">17</sub></span></span>Cl<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>), <a href="/wiki/Potassium" title="Potassium">potassium</a> (<span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">19</sub></span></span>K<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>), <a href="/wiki/Copper" title="Copper">copper</a> (<span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">29</sub></span></span>Cu<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>), <a href="/wiki/Gallium" title="Gallium">gallium</a> (<span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">31</sub></span></span>Ga<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>), <a href="/wiki/Bromine" title="Bromine">bromine</a> (<span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">35</sub></span></span>Br<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>), <a href="/wiki/Silver" title="Silver">silver</a> (<span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">47</sub></span></span>Ag<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>), <a href="/wiki/Antimony" title="Antimony">antimony</a> (<span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">51</sub></span></span>Sb<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>), <a href="/wiki/Iridium" title="Iridium">iridium</a> (<span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">77</sub></span></span>Ir<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>), and <a href="/wiki/Thallium" title="Thallium">thallium</a> (<span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">81</sub></span></span>Tl<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>), have two odd-even stable isotopes each. This makes a total <span class="nowrap">30 + 2(9) = 48</span> stable odd-even isotopes. </p><p>There are also five primordial long-lived radioactive odd-even isotopes, <span style="white-space:nowrap;"><a href="/wiki/Rubidium-87" class="mw-redirect" title="Rubidium-87"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">87</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">37</sub></span></span>Rb<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span>, <span style="white-space:nowrap;"><a href="/wiki/Indium-115" class="mw-redirect" title="Indium-115"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">115</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">49</sub></span></span>In<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span>, <span style="white-space:nowrap;"><a href="/wiki/Rhenium-187" class="mw-redirect" title="Rhenium-187"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">187</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">75</sub></span></span>Re<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span>, <span style="white-space:nowrap;"><a href="/wiki/Europium-151" class="mw-redirect" title="Europium-151"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">151</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">63</sub></span></span>Eu<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span>, and <span style="white-space:nowrap;"><a href="/wiki/Bismuth-209" title="Bismuth-209"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">209</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">83</sub></span></span>Bi<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></a></span>. The last two were only recently found to decay, with half-lives greater than 10<sup>18</sup> years. </p> <div class="mw-heading mw-heading4"><h4 id="Odd_neutron_number">Odd neutron number</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=15" title="Edit section: Odd neutron number"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <table class="wikitable" style="float:right; margin-left:1em"> <caption>Neutron number <a href="/wiki/Parity_(mathematics)" title="Parity (mathematics)">parity</a> (<a href="/wiki/Parity_of_zero" title="Parity of zero"><span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">1</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span>H<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span> as even</a>) </caption> <tbody><tr> <th>N</th> <th>Even</th> <th>Odd </th></tr> <tr> <td>Stable</td> <td>193</td> <td>58 </td></tr> <tr> <td>Long-lived</td> <td>28</td> <td>7 </td></tr> <tr> <td>All primordial</td> <td>221</td> <td>65 </td></tr></tbody></table> <p><a href="/wiki/Actinide" title="Actinide">Actinides</a> with odd neutron number are generally <a href="/wiki/Fissile" class="mw-redirect" title="Fissile">fissile</a> (with <a href="/wiki/Thermal_neutron" class="mw-redirect" title="Thermal neutron">thermal neutrons</a>), whereas those with even neutron number are generally not, though they are <a href="/wiki/Fissionable" class="mw-redirect" title="Fissionable">fissionable</a> with <a href="/wiki/Fast_neutron" class="mw-redirect" title="Fast neutron">fast neutrons</a>. All observationally stable odd-odd nuclides have nonzero integer spin. This is because the single unpaired neutron and unpaired proton have a larger <a href="/wiki/Nuclear_force" title="Nuclear force">nuclear force</a> attraction to each other if their spins are aligned (producing a total spin of at least 1 unit), instead of anti-aligned. See <a href="/wiki/Deuterium" title="Deuterium">deuterium</a> for the simplest case of this nuclear behavior. </p><p>Only <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">195</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">78</sub></span></span>Pt<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>, <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">9</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">4</sub></span></span>Be<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>, and <span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">14</sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">7</sub></span></span>N<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span> have odd neutron number and are the most naturally abundant isotope of their element. </p> <div class="mw-heading mw-heading2"><h2 id="Occurrence_in_nature">Occurrence in nature</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=16" title="Edit section: Occurrence in nature"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">See also: <a href="/wiki/Abundance_of_the_chemical_elements" title="Abundance of the chemical elements">Abundance of the chemical elements</a></div> <p>Elements are composed either of one nuclide (<a href="/wiki/Mononuclidic_element" title="Mononuclidic element">mononuclidic elements</a>), or of more than one naturally occurring isotopes. The unstable (radioactive) isotopes are either <a href="/wiki/Primordial_nuclide" title="Primordial nuclide">primordial</a> or postprimordial. Primordial isotopes were a product of <a href="/wiki/Stellar_nucleosynthesis" title="Stellar nucleosynthesis">stellar nucleosynthesis</a> or another type of nucleosynthesis such as <a href="/wiki/Cosmic_ray_spallation" title="Cosmic ray spallation">cosmic ray spallation</a>, and have persisted down to the present because their rate of decay is very slow (e.g. <a href="/wiki/Uranium-238" title="Uranium-238">uranium-238</a> and <a href="/wiki/Potassium-40" title="Potassium-40">potassium-40</a>). Post-primordial isotopes were created by <a href="/wiki/Cosmic_ray" title="Cosmic ray">cosmic ray</a> bombardment as <a href="/wiki/Cosmogenic_nuclide" title="Cosmogenic nuclide">cosmogenic nuclides</a> (e.g., <a href="/wiki/Tritium" title="Tritium">tritium</a>, <a href="/wiki/Carbon-14" title="Carbon-14">carbon-14</a>), or by the decay of a radioactive primordial isotope to a radioactive <a href="/wiki/Radiogenic_nuclide" title="Radiogenic nuclide">radiogenic nuclide</a> daughter (e.g. <a href="/wiki/Uranium" title="Uranium">uranium</a> to <a href="/wiki/Radium" title="Radium">radium</a>). A few isotopes are naturally synthesized as <a href="/wiki/Nucleogenic" title="Nucleogenic">nucleogenic</a> nuclides, by some other natural <a href="/wiki/Nuclear_reaction" title="Nuclear reaction">nuclear reaction</a>, such as when neutrons from natural <a href="/wiki/Nuclear_fission" title="Nuclear fission">nuclear fission</a> are absorbed by another atom. </p><p>As discussed above, only 80 elements have any stable isotopes, and 26 of these have only one stable isotope. Thus, about two-thirds of stable elements occur naturally on Earth in multiple stable isotopes, with the largest number of stable isotopes for an element being ten, for <a href="/wiki/Tin" title="Tin">tin</a> (<span style="white-space:nowrap;"><span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:-0.4em;line-height:1.0em;font-size:80%;text-align:right"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline">50</sub></span></span>Sn<span class="nowrap"><span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1.0em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sup><br /><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span></span>). There are about 94 elements found naturally on Earth (up to <a href="/wiki/Plutonium" title="Plutonium">plutonium</a> inclusive), though some are detected only in very tiny amounts, such as <a href="/wiki/Plutonium-244" title="Plutonium-244">plutonium-244</a>. Scientists estimate that the elements that occur naturally on Earth (some only as radioisotopes) occur as 339 isotopes (<a href="/wiki/Nuclide" title="Nuclide">nuclides</a>) in total.<sup id="cite_ref-36" class="reference"><a href="#cite_note-36"><span class="cite-bracket">[</span>36<span class="cite-bracket">]</span></a></sup> Only 251 of these naturally occurring nuclides are stable, in the sense of never having been observed to decay as of the present time. An additional 35 <a href="/wiki/Primordial_nuclide" title="Primordial nuclide">primordial nuclides</a> (to a total of 286 primordial nuclides), are radioactive with known half-lives, but have half-lives longer than 100 million years, allowing them to exist from the beginning of the Solar System. See <a href="/wiki/List_of_nuclides" title="List of nuclides">list of nuclides</a> for details. </p><p>All the known <a href="/wiki/Stable_nuclide" title="Stable nuclide">stable nuclides</a> occur naturally on Earth; the other naturally occurring nuclides are radioactive but occur on Earth due to their relatively long half-lives, or else due to other means of ongoing natural production. These include the afore-mentioned <a href="/wiki/Cosmogenic_nuclide" title="Cosmogenic nuclide">cosmogenic nuclides</a>, the <a href="/wiki/Nucleogenic" title="Nucleogenic">nucleogenic</a> nuclides, and any <a href="/wiki/Radiogenic" class="mw-redirect" title="Radiogenic">radiogenic</a> nuclides formed by ongoing decay of a primordial radioactive nuclide, such as <a href="/wiki/Radon" title="Radon">radon</a> and <a href="/wiki/Radium" title="Radium">radium</a> from uranium. </p><p>An additional ~3000 radioactive nuclides not found in nature have been created in nuclear reactors and in particle accelerators. Many short-lived nuclides not found naturally on Earth have also been observed by spectroscopic analysis, being naturally created in stars or <a href="/wiki/Supernova" title="Supernova">supernovae</a>. An example is <a href="/wiki/Aluminium-26" title="Aluminium-26">aluminium-26</a>, which is not naturally found on Earth but is found in abundance on an astronomical scale. </p><p>The tabulated atomic masses of elements are averages that account for the presence of multiple isotopes with different masses. Before the discovery of isotopes, empirically determined noninteger values of atomic mass confounded scientists. For example, a sample of <a href="/wiki/Chlorine" title="Chlorine">chlorine</a> contains 75.8% <a href="/wiki/Chlorine-35" class="mw-redirect" title="Chlorine-35">chlorine-35</a> and 24.2% <a href="/wiki/Chlorine-37" title="Chlorine-37">chlorine-37</a>, giving an average atomic mass of 35.5 <a href="/wiki/Atomic_mass_unit" class="mw-redirect" title="Atomic mass unit">atomic mass units</a>. </p><p>According to generally accepted <a href="/wiki/Physical_cosmology" title="Physical cosmology">cosmology theory</a>, only isotopes of hydrogen and helium, traces of some isotopes of lithium and beryllium, and perhaps some boron, were created at the <a href="/wiki/Big_Bang" title="Big Bang">Big Bang</a>, while all other nuclides were synthesized later, in stars and supernovae, and in interactions between energetic particles such as cosmic rays, and previously produced nuclides. (See <a href="/wiki/Nucleosynthesis" title="Nucleosynthesis">nucleosynthesis</a> for details of the various processes thought responsible for isotope production.) The respective abundances of isotopes on Earth result from the quantities formed by these processes, their spread through the galaxy, and the rates of decay for isotopes that are unstable. After the initial coalescence of the <a href="/wiki/Solar_System" title="Solar System">Solar System</a>, isotopes were redistributed according to mass, and the isotopic composition of elements varies slightly from planet to planet. This sometimes makes it possible to trace the origin of <a href="/wiki/Meteorite" title="Meteorite">meteorites</a>. </p> <div class="mw-heading mw-heading2"><h2 id="Atomic_mass_of_isotopes">Atomic mass of isotopes</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=17" title="Edit section: Atomic mass of isotopes"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The <a href="/wiki/Atomic_mass" title="Atomic mass">atomic mass</a> (<i>m</i><sub>r</sub>) of an isotope (nuclide) is determined mainly by its <a href="/wiki/Mass_number" title="Mass number">mass number</a> (i.e. number of <a href="/wiki/Nucleon" title="Nucleon">nucleons</a> in its nucleus). Small corrections are due to the <a href="/wiki/Binding_energy" title="Binding energy">binding energy</a> of the nucleus (see <a href="/wiki/Mass_defect" class="mw-redirect" title="Mass defect">mass defect</a>), the slight difference in mass between proton and neutron, and the mass of the electrons associated with the atom, the latter because the electron:nucleon ratio differs among isotopes. </p><p>The mass number is a <a href="/wiki/Dimensionless_quantity" title="Dimensionless quantity">dimensionless quantity</a>. The atomic mass, on the other hand, is measured using the <a href="/wiki/Atomic_mass_unit" class="mw-redirect" title="Atomic mass unit">atomic mass unit</a> based on the mass of the carbon-12 atom. It is denoted with symbols "u" (for unified atomic mass unit) or "Da" (for <a href="/wiki/John_Dalton" title="John Dalton">dalton</a>). </p><p>The atomic masses of naturally occurring isotopes of an element determine the <a href="/wiki/Standard_atomic_weight" title="Standard atomic weight">standard atomic weight</a> of the element. When the element contains <i>N</i> isotopes, the expression below is applied for the average atomic mass <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {\overline {m}}_{a}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mrow class="MJX-TeXAtom-ORD"> <mover> <mi>m</mi> <mo accent="false">¯</mo> </mover> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mi>a</mi> </mrow> </msub> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle {\overline {m}}_{a}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/2ff7af0c1f7e457540951dffb2849aaa199ec16b" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:3.257ex; height:2.676ex;" alt="{\displaystyle {\overline {m}}_{a}}"></span>: </p><p><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle {\overline {m}}_{a}=m_{1}x_{1}+m_{2}x_{2}+...+m_{N}x_{N}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mrow class="MJX-TeXAtom-ORD"> <mover> <mi>m</mi> <mo accent="false">¯</mo> </mover> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mi>a</mi> </mrow> </msub> <mo>=</mo> <msub> <mi>m</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>1</mn> </mrow> </msub> <msub> <mi>x</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>1</mn> </mrow> </msub> <mo>+</mo> <msub> <mi>m</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msub> <msub> <mi>x</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msub> <mo>+</mo> <mo>.</mo> <mo>.</mo> <mo>.</mo> <mo>+</mo> <msub> <mi>m</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>N</mi> </mrow> </msub> <msub> <mi>x</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>N</mi> </mrow> </msub> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle {\overline {m}}_{a}=m_{1}x_{1}+m_{2}x_{2}+...+m_{N}x_{N}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/ab8fff0ab5c50e3f7d2c91322d1b0f46cd28d47a" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:33.624ex; height:2.676ex;" alt="{\displaystyle {\overline {m}}_{a}=m_{1}x_{1}+m_{2}x_{2}+...+m_{N}x_{N}}"></span> </p><p>where <i>m</i><sub>1</sub>, <i>m</i><sub>2</sub>, ..., <i>m</i><sub><i>N</i></sub> are the atomic masses of each individual isotope, and <i>x</i><sub>1</sub>, ..., <i>x</i><sub><i>N</i></sub> are the relative abundances of these isotopes. </p> <div class="mw-heading mw-heading2"><h2 id="Applications_of_isotopes">Applications of isotopes</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=18" title="Edit section: Applications of isotopes"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading3"><h3 id="Purification_of_isotopes">Purification of isotopes</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=19" title="Edit section: Purification of isotopes"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Isotope_separation" title="Isotope separation">isotope separation</a></div> <p>Several applications exist that capitalize on the properties of the various isotopes of a given element. <a href="/wiki/Isotope_separation" title="Isotope separation">Isotope separation</a> is a significant technological challenge, particularly with heavy elements such as uranium or plutonium. Lighter elements such as lithium, carbon, nitrogen, and oxygen are commonly separated by gas diffusion of their compounds such as CO and NO. The separation of hydrogen and deuterium is unusual because it is based on chemical rather than physical properties, for example in the <a href="/wiki/Girdler_sulfide_process" title="Girdler sulfide process">Girdler sulfide process</a>. Uranium isotopes have been separated in bulk by gas diffusion, gas centrifugation, laser ionization separation, and (in the <a href="/wiki/Manhattan_Project" title="Manhattan Project">Manhattan Project</a>) by a type of production <a href="/wiki/Mass_spectrometry" title="Mass spectrometry">mass spectrometry</a>. </p> <div class="mw-heading mw-heading3"><h3 id="Use_of_chemical_and_biological_properties">Use of chemical and biological properties</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=20" title="Edit section: Use of chemical and biological properties"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main articles: <a href="/wiki/Isotope_geochemistry" title="Isotope geochemistry">isotope geochemistry</a>, <a href="/wiki/Cosmochemistry" title="Cosmochemistry">cosmochemistry</a>, and <a href="/wiki/Paleoclimatology" title="Paleoclimatology">paleoclimatology</a></div> <ul><li><a href="/wiki/Isotope_analysis" title="Isotope analysis">Isotope analysis</a> is the determination of <a href="/wiki/Isotopic_signature" title="Isotopic signature">isotopic signature</a>, the relative abundances of isotopes of a given element in a particular sample. Isotope analysis is frequently done by <a href="/wiki/Isotope_ratio_mass_spectrometry" class="mw-redirect" title="Isotope ratio mass spectrometry">isotope ratio mass spectrometry</a>. For <a href="/wiki/Biogenic_substance" title="Biogenic substance">biogenic substances</a> in particular, significant variations of isotopes of C, N, and O can occur. Analysis of such variations has a wide range of applications, such as the detection of adulteration in food products<sup id="cite_ref-Jamin_37-0" class="reference"><a href="#cite_note-Jamin-37"><span class="cite-bracket">[</span>37<span class="cite-bracket">]</span></a></sup> or the geographic origins of products using <a href="/wiki/Isoscapes" class="mw-redirect" title="Isoscapes">isoscapes</a>. The identification of <a href="/wiki/Mars_meteorite" class="mw-redirect" title="Mars meteorite">certain meteorites</a> as having originated on <a href="/wiki/Mars" title="Mars">Mars</a> is based in part upon the isotopic signature of trace gases contained in them.<sup id="cite_ref-Treiman_38-0" class="reference"><a href="#cite_note-Treiman-38"><span class="cite-bracket">[</span>38<span class="cite-bracket">]</span></a></sup></li> <li>Isotopic substitution can be used to determine the mechanism of a <a href="/wiki/Chemical_reaction" title="Chemical reaction">chemical reaction</a> via the <a href="/wiki/Kinetic_isotope_effect" title="Kinetic isotope effect">kinetic isotope effect</a>.</li> <li>Another common application is <a href="/wiki/Isotopic_labeling" title="Isotopic labeling">isotopic labeling</a>, the use of unusual isotopes as tracers or markers in chemical reactions.<sup id="cite_ref-39" class="reference"><a href="#cite_note-39"><span class="cite-bracket">[</span>39<span class="cite-bracket">]</span></a></sup> Normally, atoms of a given element are indistinguishable from each other. However, by using isotopes of different masses, even different nonradioactive <a href="/wiki/Stable_isotope" class="mw-redirect" title="Stable isotope">stable isotopes</a> can be distinguished by <a href="/wiki/Mass_spectrometry" title="Mass spectrometry">mass spectrometry</a> or <a href="/wiki/Infrared_spectroscopy" title="Infrared spectroscopy">infrared spectroscopy</a>. For example, in 'stable isotope labeling with amino acids in cell culture (<a href="/wiki/SILAC" class="mw-redirect" title="SILAC">SILAC</a>)' stable isotopes are used to quantify <a href="/wiki/Protein" title="Protein">proteins</a>. If radioactive isotopes are used, they can be detected by the radiation they emit (this is called <i>radioisotopic labeling</i>).</li> <li>Isotopes are commonly used to determine the concentration of various elements or substances using the <a href="/wiki/Isotope_dilution" title="Isotope dilution">isotope dilution</a> method, whereby known amounts of isotopically substituted compounds are mixed with the samples and the isotopic signatures of the resulting mixtures are determined with <a href="/wiki/Mass_spectrometry" title="Mass spectrometry">mass spectrometry</a>.</li></ul> <div class="mw-heading mw-heading3"><h3 id="Use_of_nuclear_properties">Use of nuclear properties</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=21" title="Edit section: Use of nuclear properties"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li>A technique similar to radioisotopic labeling is <a href="/wiki/Radiometric_dating" title="Radiometric dating">radiometric dating</a>: using the known <a href="/wiki/Half-life" title="Half-life">half-life</a> of an unstable element, one can calculate the amount of time that has elapsed since a known concentration of isotope existed. The most widely known example is <a href="/wiki/Radiocarbon_dating" title="Radiocarbon dating">radiocarbon dating</a> used to determine the age of carbonaceous materials.</li> <li>Several forms of spectroscopy rely on the unique nuclear properties of specific isotopes, both radioactive and stable. For example, <a href="/wiki/Nuclear_magnetic_resonance" title="Nuclear magnetic resonance">nuclear magnetic resonance</a> (NMR) spectroscopy can be used only for isotopes with a nonzero nuclear spin. The most common nuclides used with NMR spectroscopy are <sup>1</sup>H, <sup>2</sup>D, <sup>15</sup>N, <sup>13</sup>C, and <sup>31</sup>P.</li> <li><a href="/wiki/M%C3%B6ssbauer_spectroscopy" title="Mössbauer spectroscopy">Mössbauer spectroscopy</a> also relies on the nuclear transitions of specific isotopes, such as <sup>57</sup>Fe.</li> <li><a href="/wiki/Radionuclide" title="Radionuclide">Radionuclides</a> also have important uses. <a href="/wiki/Nuclear_power" title="Nuclear power">Nuclear power</a> and <a href="/wiki/Nuclear_weapon" title="Nuclear weapon">nuclear weapons</a> development require relatively large quantities of specific isotopes. <a href="/wiki/Nuclear_medicine" title="Nuclear medicine">Nuclear medicine</a> and <a href="/wiki/Radiation_oncology" class="mw-redirect" title="Radiation oncology">radiation oncology</a> utilize radioisotopes respectively for medical diagnosis and treatment.</li></ul> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=22" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Abundance_of_the_chemical_elements" title="Abundance of the chemical elements">Abundance of the chemical elements</a></li> <li><a href="/wiki/Bainbridge_mass_spectrometer" class="mw-redirect" title="Bainbridge mass spectrometer">Bainbridge mass spectrometer</a></li> <li><a href="/wiki/Geotraces" title="Geotraces">Geotraces</a></li> <li><a href="/wiki/Isotope_hydrology" title="Isotope hydrology">Isotope hydrology</a></li> <li><a href="/wiki/Isotopomer" title="Isotopomer">Isotopomer</a></li> <li><a href="/wiki/Nuclear_isomer" title="Nuclear isomer">Nuclear isomer</a></li> <li><a href="/wiki/List_of_nuclides" title="List of nuclides">List of nuclides</a></li> <li><a href="/wiki/List_of_particles" title="List of particles">List of particles</a></li> <li><a href="/wiki/Mass_spectrometry" title="Mass spectrometry">Mass spectrometry</a></li> <li><a href="/wiki/Reference_Materials_for_Stable_Isotope_Analysis" class="mw-redirect" title="Reference Materials for Stable Isotope Analysis">Reference materials for stable isotope analysis</a></li> <li><a href="/wiki/Table_of_nuclides" title="Table of nuclides">Table of nuclides</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=23" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist reflist-columns references-column-width" style="column-width: 35em;"> <ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output 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Archived from <a rel="nofollow" class="external text" href="http://iupap.org/wp-content/uploads/2014/05/A4.pdf">the original</a> <span class="cs1-format">(PDF)</span> on 2015-03-18<span class="reference-accessdate">. Retrieved <span class="nowrap">2018-01-06</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=IUPAP+Red+Book&rft_id=http%3A%2F%2Fiupap.org%2Fwp-content%2Fuploads%2F2014%2F05%2FA4.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AIsotope" class="Z3988"></span></span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://goldbook.iupac.org/html/I/I03331.html">IUPAC Gold Book</a></span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-7">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://goldbook.iupac.org/html/I/I03263.html">IUPAC Gold Book</a></span> </li> <li id="cite_note-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-8">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWaters2023" class="citation web cs1">Waters, Charlie (2023-09-22). <a rel="nofollow" class="external text" href="https://chemniverse.com/atomic-structure-and-isotopes-and-isotopic-notation/">"Atomic Structure And Isotopes And Isotopic Notation"</a>. <i>Chemniverse</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2024-10-23</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Chemniverse&rft.atitle=Atomic+Structure+And+Isotopes+And+Isotopic+Notation&rft.date=2023-09-22&rft.aulast=Waters&rft.aufirst=Charlie&rft_id=https%3A%2F%2Fchemniverse.com%2Fatomic-structure-and-isotopes-and-isotopic-notation%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AIsotope" class="Z3988"></span></span> </li> <li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"><a href="/wiki/IUPAC" class="mw-redirect" title="IUPAC">IUPAC</a> (Connelly, N. G.; Damhus, T.; Hartshorn, R. M.; and Hutton, A. T.), <a rel="nofollow" class="external text" href="http://old.iupac.org/publications/books/rbook/Red_Book_2005.pdf"><i>Nomenclature of Inorganic Chemistry – IUPAC Recommendations 2005</i></a>, The Royal Society of Chemistry, 2005; IUPAC (McCleverty, J. A.; and Connelly, N. G.), <i>Nomenclature of Inorganic Chemistry II. Recommendations 2000</i>, The Royal Society of Chemistry, 2001; IUPAC (Leigh, G. J.), <i>Nomenclature of Inorganic Chemistry (recommendations 1990)</i>, Blackwell Science, 1990; IUPAC, <a rel="nofollow" class="external text" href="http://pac.iupac.org/publications/pac/pdf/1971/pdf/2801x0001.pdf"><i>Nomenclature of Inorganic Chemistry, Second Edition</i></a> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20160303171046/http://pac.iupac.org/publications/pac/pdf/1971/pdf/2801x0001.pdf">Archived</a> 2016-03-03 at the <a href="/wiki/Wayback_Machine" title="Wayback Machine">Wayback Machine</a>, 1970; probably in the 1958 first edition as well</span> </li> <li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-10">^</a></b></span> <span class="reference-text">This notation seems to have been introduced in the second half of the 1930s. Before that, various notations were used, such as <a rel="nofollow" class="external text" href="https://books.google.com/books?id=jkMcAQAAIAAJ&q=isotope">Ne(22) for neon-22 (1934)</a>, <a rel="nofollow" class="external text" href="https://books.google.com/books?id=7KQOAAAAIAAJ&q=neon-22+Ne22">Ne<sup>22</sup> for neon-22 (1935)</a>, or even <a rel="nofollow" class="external text" href="https://books.google.com/books?id=HD7OAAAAMAAJ&q=isotope">Pb<sub>210</sub> for lead-210 (1933)</a>.</span> </li> <li id="cite_note-lindsay-11"><span class="mw-cite-backlink">^ <a href="#cite_ref-lindsay_11-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-lindsay_11-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.don-lindsay-archive.org/creation/isotope_list.html">"Radioactives Missing From The Earth"</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Radioactives+Missing+From+The+Earth&rft_id=http%3A%2F%2Fwww.don-lindsay-archive.org%2Fcreation%2Fisotope_list.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AIsotope" class="Z3988"></span><sup class="noprint Inline-Template"><span style="white-space: nowrap;">[<i><a href="/wiki/Wikipedia:Link_rot" title="Wikipedia:Link rot"><span title=" Dead link tagged June 2023">dead link</span></a></i><span style="visibility:hidden; color:transparent; padding-left:2px">‍</span>]</span></sup></span> </li> <li id="cite_note-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-12">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20161223072754/http://www.nndc.bnl.gov/nudat2/help/index.jsp">"NuDat 2 Description"</a>. Archived from <a rel="nofollow" class="external text" href="http://www.nndc.bnl.gov/nudat2/help/index.jsp">the original</a> on 23 December 2016<span class="reference-accessdate">. Retrieved <span class="nowrap">2 January</span> 2016</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=NuDat+2+Description&rft_id=http%3A%2F%2Fwww.nndc.bnl.gov%2Fnudat2%2Fhelp%2Findex.jsp&rfr_id=info%3Asid%2Fen.wikipedia.org%3AIsotope" class="Z3988"></span></span> </li> <li id="cite_note-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-13">^</a></b></span> <span class="reference-text">Choppin, G.; Liljenzin, J. O. and Rydberg, J.　（1995） <i>Radiochemistry and Nuclear Chemistry</i> (2nd ed.) Butterworth-Heinemann, pp. 3–5</span> </li> <li id="cite_note-14"><span class="mw-cite-backlink"><b><a href="#cite_ref-14">^</a></b></span> <span class="reference-text">Others had also suggested the possibility of isotopes; for example: <ul><li>Strömholm, Daniel and Svedberg, Theodor (1909) "Untersuchungen über die Chemie der radioactiven Grundstoffe II." (Investigations into the chemistry of the radioactive elements, part 2), <i>Zeitschrift für anorganischen Chemie</i>, <b>63</b>: 197–206; see especially page 206.</li> <li>Alexander Thomas Cameron, <i>Radiochemistry</i> (London, England: J. M. Dent & Sons, 1910), p. 141. (Cameron also anticipated the displacement law.)</li></ul> </span></li> <li id="cite_note-ley196610-15"><span class="mw-cite-backlink">^ <a href="#cite_ref-ley196610_15-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-ley196610_15-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-ley196610_15-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFLey1966" class="citation magazine cs1">Ley, Willy (October 1966). <a rel="nofollow" class="external text" href="https://archive.org/stream/Galaxy_v25n01_1966-10#page/n115/mode/2up">"The Delayed Discovery"</a>. For Your Information. <i>Galaxy Science Fiction</i>. pp. 116–127.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Galaxy+Science+Fiction&rft.atitle=The+Delayed+Discovery&rft.pages=116-127&rft.date=1966-10&rft.aulast=Ley&rft.aufirst=Willy&rft_id=https%3A%2F%2Farchive.org%2Fstream%2FGalaxy_v25n01_1966-10%23page%2Fn115%2Fmode%2F2up&rfr_id=info%3Asid%2Fen.wikipedia.org%3AIsotope" class="Z3988"></span></span> </li> <li id="cite_note-Scerri-16"><span class="mw-cite-backlink">^ <a href="#cite_ref-Scerri_16-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Scerri_16-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-Scerri_16-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text">Scerri, Eric R. (2007) <i>The Periodic Table</i> Oxford University Press, pp. 176–179 <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-19-530573-6" title="Special:BookSources/0-19-530573-6">0-19-530573-6</a></span> </li> <li id="cite_note-Nagel-17"><span class="mw-cite-backlink">^ <a href="#cite_ref-Nagel_17-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Nagel_17-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFNagel,_Miriam_C.1982" class="citation journal cs1">Nagel, Miriam C. (1982). "Frederick Soddy: From Alchemy to Isotopes". <i>Journal of Chemical Education</i>. <b>59</b> (9): 739–740. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1982JChEd..59..739N">1982JChEd..59..739N</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1021%2Fed059p739">10.1021/ed059p739</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Journal+of+Chemical+Education&rft.atitle=Frederick+Soddy%3A+From+Alchemy+to+Isotopes&rft.volume=59&rft.issue=9&rft.pages=739-740&rft.date=1982&rft_id=info%3Adoi%2F10.1021%2Fed059p739&rft_id=info%3Abibcode%2F1982JChEd..59..739N&rft.au=Nagel%2C+Miriam+C.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AIsotope" class="Z3988"></span></span> </li> <li id="cite_note-18"><span class="mw-cite-backlink"><b><a href="#cite_ref-18">^</a></b></span> <span class="reference-text">Kasimir Fajans (1913) "Über eine Beziehung zwischen der Art einer radioaktiven Umwandlung und dem elektrochemischen Verhalten der betreffenden Radioelemente" (On a relation between the type of radioactive transformation and the electrochemical behavior of the relevant radioactive elements), <i>Physikalische Zeitschrift</i>, <b>14</b>: 131–136.</span> </li> <li id="cite_note-19"><span class="mw-cite-backlink"><b><a href="#cite_ref-19">^</a></b></span> <span class="reference-text">Soddy announced his "displacement law" in: <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSoddy1913" class="citation journal cs1">Soddy, Frederick (1913). <a rel="nofollow" class="external text" href="https://zenodo.org/record/1429562">"The Radio-Elements and the Periodic Law"</a>. <i>Nature</i>. <b>91</b> (2264): 57–58. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1913Natur..91...57S">1913Natur..91...57S</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1038%2F091057a0">10.1038/091057a0</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:3975657">3975657</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Nature&rft.atitle=The+Radio-Elements+and+the+Periodic+Law&rft.volume=91&rft.issue=2264&rft.pages=57-58&rft.date=1913&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A3975657%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.1038%2F091057a0&rft_id=info%3Abibcode%2F1913Natur..91...57S&rft.aulast=Soddy&rft.aufirst=Frederick&rft_id=https%3A%2F%2Fzenodo.org%2Frecord%2F1429562&rfr_id=info%3Asid%2Fen.wikipedia.org%3AIsotope" class="Z3988"></span>.</span> </li> <li id="cite_note-20"><span class="mw-cite-backlink"><b><a href="#cite_ref-20">^</a></b></span> <span class="reference-text">Soddy elaborated his displacement law in: Soddy, Frederick (1913) "Radioactivity," <i>Chemical Society Annual Report</i>, <b>10</b>: 262–288.</span> </li> <li id="cite_note-21"><span class="mw-cite-backlink"><b><a href="#cite_ref-21">^</a></b></span> <span class="reference-text">Alexander Smith Russell (1888–1972) also published a displacement law: Russell, Alexander S. (1913) "The periodic system and the radio-elements," <i>Chemical News and Journal of Industrial Science</i>, <b>107</b>: 49–52.</span> </li> <li id="cite_note-22"><span class="mw-cite-backlink"><b><a href="#cite_ref-22">^</a></b></span> <span class="reference-text">Soddy first used the word "isotope" in: <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSoddy,_Frederick1913" class="citation journal cs1">Soddy, Frederick (1913). <a rel="nofollow" class="external text" href="http://www.nature.com/physics/looking-back/soddy/index.html">"Intra-atomic charge"</a>. <i>Nature</i>. <b>92</b> (2301): 399–400. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1913Natur..92..399S">1913Natur..92..399S</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1038%2F092399c0">10.1038/092399c0</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:3965303">3965303</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Nature&rft.atitle=Intra-atomic+charge&rft.volume=92&rft.issue=2301&rft.pages=399-400&rft.date=1913&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A3965303%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.1038%2F092399c0&rft_id=info%3Abibcode%2F1913Natur..92..399S&rft.au=Soddy%2C+Frederick&rft_id=http%3A%2F%2Fwww.nature.com%2Fphysics%2Flooking-back%2Fsoddy%2Findex.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3AIsotope" class="Z3988"></span></span> </li> <li id="cite_note-23"><span class="mw-cite-backlink"><b><a href="#cite_ref-23">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFFleck,_Alexander1957" class="citation journal cs1">Fleck, Alexander (1957). <a rel="nofollow" class="external text" href="https://doi.org/10.1098%2Frsbm.1957.0014">"Frederick Soddy"</a>. <i>Biographical Memoirs of Fellows of the Royal Society</i>. <b>3</b>: 203–216. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1098%2Frsbm.1957.0014">10.1098/rsbm.1957.0014</a></span>. <q>p. 208: Up to 1913 we used the phrase 'radio elements chemically non-separable' and at that time the word isotope was suggested in a drawing-room discussion with Dr. Margaret Todd in the home of Soddy's father-in-law, Sir <a href="/wiki/George_Beilby" title="George Beilby">George Beilby</a>.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Biographical+Memoirs+of+Fellows+of+the+Royal+Society&rft.atitle=Frederick+Soddy&rft.volume=3&rft.pages=203-216&rft.date=1957&rft_id=info%3Adoi%2F10.1098%2Frsbm.1957.0014&rft.au=Fleck%2C+Alexander&rft_id=https%3A%2F%2Fdoi.org%2F10.1098%252Frsbm.1957.0014&rfr_id=info%3Asid%2Fen.wikipedia.org%3AIsotope" class="Z3988"></span></span> </li> <li id="cite_note-pmid16134128-24"><span class="mw-cite-backlink"><b><a href="#cite_ref-pmid16134128_24-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBudzikiewiczGrigsby2006" class="citation journal cs1">Budzikiewicz H, Grigsby RD (2006). "Mass spectrometry and isotopes: a century of research and discussion". <i>Mass Spectrometry Reviews</i>. <b>25</b> (1): 146–57. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2006MSRv...25..146B">2006MSRv...25..146B</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1002%2Fmas.20061">10.1002/mas.20061</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/16134128">16134128</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Mass+Spectrometry+Reviews&rft.atitle=Mass+spectrometry+and+isotopes%3A+a+century+of+research+and+discussion&rft.volume=25&rft.issue=1&rft.pages=146-57&rft.date=2006&rft_id=info%3Apmid%2F16134128&rft_id=info%3Adoi%2F10.1002%2Fmas.20061&rft_id=info%3Abibcode%2F2006MSRv...25..146B&rft.aulast=Budzikiewicz&rft.aufirst=H&rft.au=Grigsby%2C+RD&rfr_id=info%3Asid%2Fen.wikipedia.org%3AIsotope" class="Z3988"></span></span> </li> <li id="cite_note-25"><span class="mw-cite-backlink"><b><a href="#cite_ref-25">^</a></b></span> <span class="reference-text">Scerri, Eric R. (2007) <i>The Periodic Table</i>, Oxford University Press, <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-19-530573-6" title="Special:BookSources/0-19-530573-6">0-19-530573-6</a>, Ch. 6, note 44 (p. 312) citing <a href="/wiki/Alexander_Fleck" class="mw-redirect" title="Alexander Fleck">Alexander Fleck</a>, described as a former student of Soddy's.</span> </li> <li id="cite_note-26"><span class="mw-cite-backlink"><b><a href="#cite_ref-26">^</a></b></span> <span class="reference-text">In his 1893 book, William T. Preyer also used the word "isotope" to denote similarities among elements. From <a rel="nofollow" class="external text" href="https://books.google.com/books?id=8zDsAAAAMAAJ&pg=PA9">p. 9</a> of William T. Preyer, <i>Das genetische System der chemischen Elemente</i> [The genetic system of the chemical elements] (Berlin, Germany: R. Friedländer & Sohn, 1893): "Die ersteren habe ich der Kürze wegen isotope Elemente genannt, weil sie in jedem der sieben Stämmme der gleichen Ort, nämlich dieselbe Stuffe, einnehmen." (For the sake of brevity, I have named the former "isotopic" elements, because they occupy the same place in each of the seven families [i.e., columns of the periodic table], namely the same step [i.e., row of the periodic table].)</span> </li> <li id="cite_note-soddynobel-27"><span class="mw-cite-backlink">^ <a href="#cite_ref-soddynobel_27-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-soddynobel_27-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="https://www.nobelprize.org/nobel_prizes/chemistry/laureates/1921/soddy-lecture.html">The origins of the conceptions of isotopes</a> Frederick Soddy, Nobel prize lecture</span> </li> <li id="cite_note-28"><span class="mw-cite-backlink"><b><a href="#cite_ref-28">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFThomson1912" class="citation journal cs1">Thomson, J. J. (1912). <a rel="nofollow" class="external text" href="https://zenodo.org/record/1430842">"XIX. Further experiments on positive rays"</a>. <i>Philosophical Magazine</i>. 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title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Scientific+Reports&rft.atitle=Boron+isotope+fractionation+in+magma+via+crustal+carbonate+dissolution&rft.volume=6&rft.issue=1&rft.pages=30774&rft.date=2016-08-04&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC4973271%23id-name%3DPMC&rft_id=info%3Abibcode%2F2016NatSR...630774D&rft_id=info%3Apmid%2F27488228&rft_id=info%3Adoi%2F10.1038%2Fsrep30774&rft.issn=2045-2322&rft.aulast=Deegan&rft.aufirst=Frances+M.&rft.au=Troll%2C+Valentin+R.&rft.au=Whitehouse%2C+Martin+J.&rft.au=Jolis%2C+Ester+M.&rft.au=Freda%2C+Carmela&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC4973271&rfr_id=info%3Asid%2Fen.wikipedia.org%3AIsotope" class="Z3988"></span></span> </li> </ol></div> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Isotope&action=edit&section=24" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a rel="nofollow" class="external text" href="http://www.nucleonica.com/">The Nuclear Science web portal Nucleonica</a></li> <li><a rel="nofollow" class="external text" href="http://www.nucleonica.com/wiki/index.php?title=Category%3AKNC">The Karlsruhe Nuclide Chart</a></li> <li><a rel="nofollow" class="external text" href="http://www.nndc.bnl.gov/">National Nuclear Data Center</a> Portal to large repository of free data and analysis programs from NNDC</li> <li><a rel="nofollow" class="external text" href="https://isotopes.gov/">National Isotope Development Center</a> Coordination and management of the production, availability, and distribution of isotopes, and reference information for the isotope community</li> <li><a rel="nofollow" class="external text" href="http://science.energy.gov/np/research/idpra/">Isotope Development & Production for Research and Applications (IDPRA)</a> U.S. Department of Energy program for isotope production and production research and development</li> <li><a rel="nofollow" class="external text" href="http://www.iaea.org/">International Atomic Energy Agency</a> Homepage of <a href="/wiki/International_Atomic_Energy_Agency" title="International Atomic Energy Agency">International Atomic Energy Agency</a> (IAEA), an Agency of the <a href="/wiki/United_Nations" title="United Nations">United Nations</a> (UN)</li> <li><a rel="nofollow" class="external text" href="http://physics.nist.gov/cgi-bin/Compositions/stand_alone.pl?ele=&ascii=html&isotype=some">Atomic Weights and Isotopic Compositions for All Elements</a> Static table, from NIST (<a href="/wiki/National_Institute_of_Standards_and_Technology" title="National Institute of Standards and Technology">National Institute of Standards and Technology</a>)</li> <li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20070121042708/http://atom.kaeri.re.kr/">Atomgewichte, Zerfallsenergien und Halbwertszeiten aller Isotope</a></li> <li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20061205022425/http://ie.lbl.gov/education/isotopes.htm">Exploring the Table of the Isotopes</a> at the <a href="/wiki/LBNL" class="mw-redirect" title="LBNL">LBNL</a></li> <li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20141217141609/http://isotope.info/">Current isotope research and information</a> isotope.info</li> <li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20070825124014/http://www.bt.cdc.gov/radiation/isotopes/">Emergency Preparedness and Response: Radioactive Isotopes</a> by the CDC (<a href="/wiki/Centers_for_Disease_Control_and_Prevention" title="Centers for Disease Control and Prevention">Centers for Disease Control and Prevention</a>)</li> <li><a rel="nofollow" class="external text" href="http://www.nndc.bnl.gov/chart/">Chart of Nuclides</a> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20181010070007/http://www.nndc.bnl.gov/chart/">Archived</a> 2018-10-10 at the <a href="/wiki/Wayback_Machine" title="Wayback Machine">Wayback Machine</a> Interactive Chart of Nuclides (National Nuclear Data Center)</li> <li><a rel="nofollow" class="external text" href="http://www.yoix.org/elements.html">Interactive Chart of the nuclides, isotopes and Periodic Table</a> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20080930194927/http://www.yoix.org/elements.html">Archived</a> 2008-09-30 at the <a href="/wiki/Wayback_Machine" title="Wayback Machine">Wayback Machine</a></li> <li><a rel="nofollow" class="external text" href="http://www-nds.iaea.org/livechart">The LIVEChart of Nuclides – IAEA</a> with isotope data.</li> <li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20120330123733/http://alsos.wlu.edu/adv_rst.aspx?keyword=isotope&creator=&title=&media=all&genre=all&disc=all&level=all&sortby=relevance&results=10&period=15">Annotated bibliography for isotopes</a> from the Alsos Digital Library for Nuclear Issues</li> <li><a rel="nofollow" class="external text" href="https://www.youtube.com/watch?v=UTOp_2ZVZmM&t=192">The Valley of Stability (video)</a> – a virtual "flight" through 3D representation of the nuclide chart, by <a href="/wiki/French_Alternative_Energies_and_Atomic_Energy_Commission" title="French Alternative Energies and Atomic Energy Commission">CEA</a> (France)</li></ul> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><style data-mw-deduplicate="TemplateStyles:r1236075235">.mw-parser-output .navbox{box-sizing:border-box;border:1px solid #a2a9b1;width:100%;clear:both;font-size:88%;text-align:center;padding:1px;margin:1em auto 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.navbox-abovebelow,.mw-parser-output .navbox-group,.mw-parser-output .navbox-subgroup .navbox-title{background-color:#ddf}.mw-parser-output .navbox-subgroup .navbox-group,.mw-parser-output .navbox-subgroup .navbox-abovebelow{background-color:#e6e6ff}.mw-parser-output .navbox-even{background-color:#f7f7f7}.mw-parser-output .navbox-odd{background-color:transparent}.mw-parser-output .navbox .hlist td dl,.mw-parser-output .navbox .hlist td ol,.mw-parser-output .navbox .hlist td ul,.mw-parser-output .navbox td.hlist dl,.mw-parser-output .navbox td.hlist ol,.mw-parser-output .navbox td.hlist ul{padding:0.125em 0}.mw-parser-output .navbox .navbar{display:block;font-size:100%}.mw-parser-output .navbox-title .navbar{float:left;text-align:left;margin-right:0.5em}body.skin--responsive .mw-parser-output .navbox-image img{max-width:none!important}@media print{body.ns-0 .mw-parser-output .navbox{display:none!important}}</style></div><div role="navigation" class="navbox" aria-labelledby="Isotopes_of_the_chemical_elements" style="padding:3px"><table class="nowraplinks mw-collapsible expanded navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Navbox_element_isotopes" title="Template:Navbox element isotopes"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Navbox_element_isotopes" title="Template talk:Navbox element isotopes"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Navbox_element_isotopes" title="Special:EditPage/Template:Navbox element isotopes"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Isotopes_of_the_chemical_elements" style="font-size:114%;margin:0 4em"><a class="mw-selflink selflink">Isotopes</a> of the <a href="/wiki/Chemical_element" title="Chemical element">chemical elements</a></div></th></tr><tr><td colspan="2" class="navbox-list navbox-odd" style="width:100%;padding:0;line-height:110%;"><div style="padding:0 0.25em"> <table style="border-spacing:1px;display:block;overflow:auto;width:100%;margin:0 !important"> <tbody><tr style="line-height:125%; vertical-align:top;"> <th style="text-align:right; width:3%; background:transparent"><small><a href="/wiki/Group_(periodic_table)" title="Group (periodic table)">Group</a></small> </th> <th style="background:#e8e8e8; width:5%"><a href="/wiki/Alkali_metal" title="Alkali metal">1</a> </th> <th style="background:#f0f0f0; width:5%"><a href="/wiki/Alkaline_earth_metal" title="Alkaline earth metal">2</a> </th> <td style="width:2%">  </td> <th style="background:#e8e8e8; width:5%"><a href="/wiki/Group_3_element" title="Group 3 element">3</a> </th> <th style="background:#f0f0f0; width:5%"><a href="/wiki/Group_4_element" title="Group 4 element">4</a> </th> <th style="background:#e8e8e8; width:5%"><a href="/wiki/Group_5_element" title="Group 5 element">5</a> </th> <th style="background:#f0f0f0; width:5%"><a href="/wiki/Group_6_element" title="Group 6 element">6</a> </th> <th style="background:#e8e8e8; width:5%"><a href="/wiki/Group_7_element" title="Group 7 element">7</a> </th> <th style="background:#f0f0f0; width:5%"><a href="/wiki/Group_8_element" title="Group 8 element">8</a> </th> <th style="background:#e8e8e8; width:5%"><a href="/wiki/Group_9_element" title="Group 9 element">9</a> </th> <th style="background:#f0f0f0; width:5%"><a href="/wiki/Group_10_element" title="Group 10 element">10</a> </th> <th style="background:#e8e8e8; width:5%"><a href="/wiki/Group_11_element" title="Group 11 element">11</a> </th> <th style="background:#f0f0f0; width:5%"><a href="/wiki/Group_12_element" title="Group 12 element">12</a> </th> <th style="background:#e8e8e8; width:5%"><a href="/wiki/Boron_group" title="Boron group">13</a> </th> <th style="background:#f0f0f0; width:5%"><a href="/wiki/Carbon_group" title="Carbon group">14</a> </th> <th style="background:#e8e8e8; width:5%"><a href="/wiki/Pnictogen" title="Pnictogen">15</a> </th> <th style="background:#f0f0f0; width:5%"><a href="/wiki/Chalcogen" title="Chalcogen">16</a> </th> <th style="background:#e8e8e8; width:5%"><a href="/wiki/Halogen" title="Halogen">17</a> </th> <th style="background:#f0f0f0; width:5%"><a href="/wiki/Noble_gas" title="Noble gas">18</a> </th></tr> <tr style="font-size:85%; line-height:125%; vertical-align:top;"> <th style="text-align:left; vertical-align:bottom; background:transparent"><small><a href="/wiki/Period_(periodic_table)" title="Period (periodic table)">Period</a></small> </th> <td style="background:#e8e8e8;">Hydrogen and<br />alkali metals </td> <td style="background:#f0f0f0;">Alkaline<br />earth metals </td> <td> </td> <td style="background:#e8e8e8;"> </td> <td style="background:#f0f0f0;"> </td> <td style="background:#e8e8e8;"> </td> <td style="background:#f0f0f0;"> </td> <td style="background:#e8e8e8;"> </td> <td style="background:#f0f0f0;"> </td> <td style="background:#e8e8e8;"> </td> <td style="background:#f0f0f0;"> </td> <td style="background:#e8e8e8;"> </td> <td style="background:#f0f0f0;"> </td> <td style="background:#e8e8e8;"> </td> <td style="background:#f0f0f0;"> </td> <td style="background:#e8e8e8;">Pnictogens </td> <td style="background:#f0f0f0;">Chalcogens </td> <td style="background:#e8e8e8;">Halogens </td> <td style="background:#f0f0f0;">Noble gases </td></tr> <tr> <th style="background:transparent"><span title="Period ①" class="nounderlines" style="font-size:150%;"><a href="/wiki/Period_1_element" title="Period 1 element">①</a></span> </th> <td style="padding-left:0.1em; background:#ff9999;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_hydrogen" title="Isotopes of hydrogen">Isotopes</a>  <a href="/wiki/Isotopes_of_hydrogen#List_of_isotopes" title="Isotopes of hydrogen">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Hydrogen" title="Hydrogen">H</a></b></div>1 </td> <td colspan="17"> </td> <td style="padding-left:0.1em; background:#ff9999;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_helium" title="Isotopes of helium">Isotopes</a>  <a href="/wiki/Isotopes_of_helium#List_of_isotopes" title="Isotopes of helium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Helium" title="Helium">He</a></b></div>2 </td></tr> <tr> <th style="background:transparent"><span title="Period ②" class="nounderlines" style="font-size:150%;"><a href="/wiki/Period_2_element" title="Period 2 element">②</a></span> </th> <td style="padding-left:0.1em; background:#ff9999;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_lithium" title="Isotopes of lithium">Isotopes</a>  <a href="/wiki/Isotopes_of_lithium#List_of_isotopes" title="Isotopes of lithium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Lithium" title="Lithium">Li</a></b></div>3 </td> <td style="padding-left:0.1em; background:#ff9999;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_beryllium" title="Isotopes of beryllium">Isotopes</a>  <a href="/wiki/Isotopes_of_beryllium#List_of_isotopes" title="Isotopes of beryllium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Beryllium" title="Beryllium">Be</a></b></div>4 </td> <td colspan="11"> </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_boron" title="Isotopes of boron">Isotopes</a>  <a href="/wiki/Isotopes_of_boron#List_of_isotopes" title="Isotopes of boron">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Boron" title="Boron">B</a></b></div>5 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_carbon" title="Isotopes of carbon">Isotopes</a>  <a href="/wiki/Isotopes_of_carbon#List_of_isotopes" title="Isotopes of carbon">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Carbon" title="Carbon">C</a></b></div>6 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_nitrogen" title="Isotopes of nitrogen">Isotopes</a>  <a href="/wiki/Isotopes_of_nitrogen#List_of_isotopes" title="Isotopes of nitrogen">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Nitrogen" title="Nitrogen">N</a></b></div>7 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_oxygen" title="Isotopes of oxygen">Isotopes</a>  <a href="/wiki/Isotopes_of_oxygen#List_of_isotopes" title="Isotopes of oxygen">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Oxygen" title="Oxygen">O</a></b></div>8 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_fluorine" title="Isotopes of fluorine">Isotopes</a>  <a href="/wiki/Isotopes_of_fluorine#List_of_isotopes" title="Isotopes of fluorine">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Fluorine" title="Fluorine">F</a></b></div>9 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_neon" title="Isotopes of neon">Isotopes</a>  <a href="/wiki/Isotopes_of_neon#List_of_isotopes" title="Isotopes of neon">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Neon" title="Neon">Ne</a></b></div>10 </td></tr> <tr> <th style="background:transparent"><span title="Period ③" class="nounderlines" style="font-size:150%;"><a href="/wiki/Period_3_element" title="Period 3 element">③</a></span> </th> <td style="padding-left:0.1em; background:#ff9999;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_sodium" title="Isotopes of sodium">Isotopes</a>  <a href="/wiki/Isotopes_of_sodium#List_of_isotopes" title="Isotopes of sodium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Sodium" title="Sodium">Na</a></b></div>11 </td> <td style="padding-left:0.1em; background:#ff9999;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_magnesium" title="Isotopes of magnesium">Isotopes</a>  <a href="/wiki/Isotopes_of_magnesium#List_of_isotopes" title="Isotopes of magnesium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Magnesium" title="Magnesium">Mg</a></b></div>12 </td> <td colspan="11"> </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_aluminium" title="Isotopes of aluminium">Isotopes</a>  <a href="/wiki/Isotopes_of_aluminium#List_of_isotopes" title="Isotopes of aluminium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Aluminium" title="Aluminium">Al</a></b></div>13 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_silicon" title="Isotopes of silicon">Isotopes</a>  <a href="/wiki/Isotopes_of_silicon#List_of_isotopes" title="Isotopes of silicon">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Silicon" title="Silicon">Si</a></b></div>14 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_phosphorus" title="Isotopes of phosphorus">Isotopes</a>  <a href="/wiki/Isotopes_of_phosphorus#List_of_isotopes" title="Isotopes of phosphorus">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Phosphorus" title="Phosphorus">P</a></b></div>15 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_sulfur" title="Isotopes of sulfur">Isotopes</a>  <a href="/wiki/Isotopes_of_sulfur#List_of_isotopes" title="Isotopes of sulfur">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Sulfur" title="Sulfur">S</a></b></div>16 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_chlorine" title="Isotopes of chlorine">Isotopes</a>  <a href="/wiki/Isotopes_of_chlorine#List_of_isotopes" title="Isotopes of chlorine">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Chlorine" title="Chlorine">Cl</a></b></div>17 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_argon" title="Isotopes of argon">Isotopes</a>  <a href="/wiki/Isotopes_of_argon#List_of_isotopes" title="Isotopes of argon">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Argon" title="Argon">Ar</a></b></div>18 </td></tr> <tr> <th style="background:transparent"><span title="Period ④" class="nounderlines" style="font-size:150%;"><a href="/wiki/Period_4_element" title="Period 4 element">④</a></span> </th> <td style="padding-left:0.1em; background:#ff9999;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_potassium" title="Isotopes of potassium">Isotopes</a>  <a href="/wiki/Isotopes_of_potassium#List_of_isotopes" title="Isotopes of potassium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Potassium" title="Potassium">K</a></b></div>19 </td> <td style="padding-left:0.1em; background:#ff9999;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_calcium" title="Isotopes of calcium">Isotopes</a>  <a href="/wiki/Isotopes_of_calcium#List_of_isotopes" title="Isotopes of calcium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Calcium" title="Calcium">Ca</a></b></div>20 </td> <td> </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_scandium" title="Isotopes of scandium">Isotopes</a>  <a href="/wiki/Isotopes_of_scandium#List_of_isotopes" title="Isotopes of scandium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Scandium" title="Scandium">Sc</a></b></div>21 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_titanium" title="Isotopes of titanium">Isotopes</a>  <a href="/wiki/Isotopes_of_titanium#List_of_isotopes" title="Isotopes of titanium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Titanium" title="Titanium">Ti</a></b></div>22 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_vanadium" title="Isotopes of vanadium">Isotopes</a>  <a href="/wiki/Isotopes_of_vanadium#List_of_isotopes" title="Isotopes of vanadium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Vanadium" title="Vanadium">V</a></b></div>23 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_chromium" title="Isotopes of chromium">Isotopes</a>  <a href="/wiki/Isotopes_of_chromium#List_of_isotopes" title="Isotopes of chromium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Chromium" title="Chromium">Cr</a></b></div>24 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_manganese" title="Isotopes of manganese">Isotopes</a>  <a href="/wiki/Isotopes_of_manganese#List_of_isotopes" title="Isotopes of manganese">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Manganese" title="Manganese">Mn</a></b></div>25 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_iron" title="Isotopes of iron">Isotopes</a>  <a href="/wiki/Isotopes_of_iron#List_of_isotopes" title="Isotopes of iron">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Iron" title="Iron">Fe</a></b></div>26 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_cobalt" title="Isotopes of cobalt">Isotopes</a>  <a href="/wiki/Isotopes_of_cobalt#List_of_isotopes" title="Isotopes of cobalt">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Cobalt" title="Cobalt">Co</a></b></div>27 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_nickel" title="Isotopes of nickel">Isotopes</a>  <a href="/wiki/Isotopes_of_nickel#List_of_isotopes" title="Isotopes of nickel">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Nickel" title="Nickel">Ni</a></b></div>28 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_copper" title="Isotopes of copper">Isotopes</a>  <a href="/wiki/Isotopes_of_copper#List_of_isotopes" title="Isotopes of copper">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Copper" title="Copper">Cu</a></b></div>29 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_zinc" title="Isotopes of zinc">Isotopes</a>  <a href="/wiki/Isotopes_of_zinc#List_of_isotopes" title="Isotopes of zinc">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Zinc" title="Zinc">Zn</a></b></div>30 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_gallium" title="Isotopes of gallium">Isotopes</a>  <a href="/wiki/Isotopes_of_gallium#List_of_isotopes" title="Isotopes of gallium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Gallium" title="Gallium">Ga</a></b></div>31 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_germanium" title="Isotopes of germanium">Isotopes</a>  <a href="/wiki/Isotopes_of_germanium#List_of_isotopes" title="Isotopes of germanium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Germanium" title="Germanium">Ge</a></b></div>32 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_arsenic" title="Isotopes of arsenic">Isotopes</a>  <a href="/wiki/Isotopes_of_arsenic#List_of_isotopes" title="Isotopes of arsenic">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Arsenic" title="Arsenic">As</a></b></div>33 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_selenium" title="Isotopes of selenium">Isotopes</a>  <a href="/wiki/Isotopes_of_selenium#List_of_isotopes" title="Isotopes of selenium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Selenium" title="Selenium">Se</a></b></div>34 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_bromine" title="Isotopes of bromine">Isotopes</a>  <a href="/wiki/Isotopes_of_bromine#List_of_isotopes" title="Isotopes of bromine">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Bromine" title="Bromine">Br</a></b></div>35 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_krypton" title="Isotopes of krypton">Isotopes</a>  <a href="/wiki/Isotopes_of_krypton#List_of_isotopes" title="Isotopes of krypton">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Krypton" title="Krypton">Kr</a></b></div>36 </td></tr> <tr> <th style="background:transparent"><span title="Period ⑤" class="nounderlines" style="font-size:150%;"><a href="/wiki/Period_5_element" title="Period 5 element">⑤</a></span> </th> <td style="padding-left:0.1em; background:#ff9999;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_rubidium" title="Isotopes of rubidium">Isotopes</a>  <a href="/wiki/Isotopes_of_rubidium#List_of_isotopes" title="Isotopes of rubidium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Rubidium" title="Rubidium">Rb</a></b></div>37 </td> <td style="padding-left:0.1em; background:#ff9999;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_strontium" title="Isotopes of strontium">Isotopes</a>  <a href="/wiki/Isotopes_of_strontium#List_of_isotopes" title="Isotopes of strontium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Strontium" title="Strontium">Sr</a></b></div>38 </td> <td> </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_yttrium" title="Isotopes of yttrium">Isotopes</a>  <a href="/wiki/Isotopes_of_yttrium#List_of_isotopes" title="Isotopes of yttrium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Yttrium" title="Yttrium">Y</a></b></div>39 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_zirconium" title="Isotopes of zirconium">Isotopes</a>  <a href="/wiki/Isotopes_of_zirconium#List_of_isotopes" title="Isotopes of zirconium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Zirconium" title="Zirconium">Zr</a></b></div>40 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_niobium" title="Isotopes of niobium">Isotopes</a>  <a href="/wiki/Isotopes_of_niobium#List_of_isotopes" title="Isotopes of niobium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Niobium" title="Niobium">Nb</a></b></div>41 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_molybdenum" title="Isotopes of molybdenum">Isotopes</a>  <a href="/wiki/Isotopes_of_molybdenum#List_of_isotopes" title="Isotopes of molybdenum">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Molybdenum" title="Molybdenum">Mo</a></b></div>42 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_technetium" title="Isotopes of technetium">Isotopes</a>  <a href="/wiki/Isotopes_of_technetium#List_of_isotopes" title="Isotopes of technetium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Technetium" title="Technetium">Tc</a></b></div>43 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_ruthenium" title="Isotopes of ruthenium">Isotopes</a>  <a href="/wiki/Isotopes_of_ruthenium#List_of_isotopes" title="Isotopes of ruthenium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Ruthenium" title="Ruthenium">Ru</a></b></div>44 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_rhodium" title="Isotopes of rhodium">Isotopes</a>  <a href="/wiki/Isotopes_of_rhodium#List_of_isotopes" title="Isotopes of rhodium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Rhodium" title="Rhodium">Rh</a></b></div>45 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_palladium" title="Isotopes of palladium">Isotopes</a>  <a href="/wiki/Isotopes_of_palladium#List_of_isotopes" title="Isotopes of palladium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Palladium" title="Palladium">Pd</a></b></div>46 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_silver" title="Isotopes of silver">Isotopes</a>  <a href="/wiki/Isotopes_of_silver#List_of_isotopes" title="Isotopes of silver">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Silver" title="Silver">Ag</a></b></div>47 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_cadmium" title="Isotopes of cadmium">Isotopes</a>  <a href="/wiki/Isotopes_of_cadmium#List_of_isotopes" title="Isotopes of cadmium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Cadmium" title="Cadmium">Cd</a></b></div>48 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_indium" title="Isotopes of indium">Isotopes</a>  <a href="/wiki/Isotopes_of_indium#List_of_isotopes" title="Isotopes of indium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Indium" title="Indium">In</a></b></div>49 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_tin" title="Isotopes of tin">Isotopes</a>  <a href="/wiki/Isotopes_of_tin#List_of_isotopes" title="Isotopes of tin">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Tin" title="Tin">Sn</a></b></div>50 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_antimony" title="Isotopes of antimony">Isotopes</a>  <a href="/wiki/Isotopes_of_antimony#List_of_isotopes" title="Isotopes of antimony">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Antimony" title="Antimony">Sb</a></b></div>51 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_tellurium" title="Isotopes of tellurium">Isotopes</a>  <a href="/wiki/Isotopes_of_tellurium#List_of_isotopes" title="Isotopes of tellurium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Tellurium" title="Tellurium">Te</a></b></div>52 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_iodine" title="Isotopes of iodine">Isotopes</a>  <a href="/wiki/Isotopes_of_iodine#List_of_isotopes" title="Isotopes of iodine">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Iodine" title="Iodine">I</a></b></div>53 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_xenon" title="Isotopes of xenon">Isotopes</a>  <a href="/wiki/Isotopes_of_xenon#List_of_isotopes" title="Isotopes of xenon">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Xenon" title="Xenon">Xe</a></b></div>54 </td></tr> <tr> <th style="background:transparent"><span title="Period ⑥" class="nounderlines" style="font-size:150%;"><a href="/wiki/Period_6_element" title="Period 6 element">⑥</a></span> </th> <td style="padding-left:0.1em; background:#ff9999;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_caesium" title="Isotopes of caesium">Isotopes</a>  <a href="/wiki/Isotopes_of_caesium#List_of_isotopes" title="Isotopes of caesium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Caesium" title="Caesium">Cs</a></b></div>55 </td> <td style="padding-left:0.1em; background:#ff9999;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_barium" title="Isotopes of barium">Isotopes</a>  <a href="/wiki/Isotopes_of_barium#List_of_isotopes" title="Isotopes of barium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Barium" title="Barium">Ba</a></b></div>56 </td> <td style="text-align:center; vertical-align:middle; background:#9bff99;"><span class="skin-invert-image" typeof="mw:File"><span><img alt="1 asterisk" src="//upload.wikimedia.org/wikipedia/commons/thumb/4/49/Asterisks_one.svg/16px-Asterisks_one.svg.png" decoding="async" width="16" height="15" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/49/Asterisks_one.svg/24px-Asterisks_one.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/49/Asterisks_one.svg/32px-Asterisks_one.svg.png 2x" data-file-width="106" data-file-height="98" /></span></span> </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_lutetium" title="Isotopes of lutetium">Isotopes</a>  <a href="/wiki/Isotopes_of_lutetium#List_of_isotopes" title="Isotopes of lutetium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Lutetium" title="Lutetium">Lu</a></b></div>71 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_hafnium" title="Isotopes of hafnium">Isotopes</a>  <a href="/wiki/Isotopes_of_hafnium#List_of_isotopes" title="Isotopes of hafnium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Hafnium" title="Hafnium">Hf</a></b></div>72 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_tantalum" title="Isotopes of tantalum">Isotopes</a>  <a href="/wiki/Isotopes_of_tantalum#List_of_isotopes" title="Isotopes of tantalum">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Tantalum" title="Tantalum">Ta</a></b></div>73 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_tungsten" title="Isotopes of tungsten">Isotopes</a>  <a href="/wiki/Isotopes_of_tungsten#List_of_isotopes" title="Isotopes of tungsten">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Tungsten" title="Tungsten">W</a></b></div>74 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_rhenium" title="Isotopes of rhenium">Isotopes</a>  <a href="/wiki/Isotopes_of_rhenium#List_of_isotopes" title="Isotopes of rhenium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Rhenium" title="Rhenium">Re</a></b></div>75 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_osmium" title="Isotopes of osmium">Isotopes</a>  <a href="/wiki/Isotopes_of_osmium#List_of_isotopes" title="Isotopes of osmium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Osmium" title="Osmium">Os</a></b></div>76 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_iridium" title="Isotopes of iridium">Isotopes</a>  <a href="/wiki/Isotopes_of_iridium#List_of_isotopes" title="Isotopes of iridium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Iridium" title="Iridium">Ir</a></b></div>77 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_platinum" title="Isotopes of platinum">Isotopes</a>  <a href="/wiki/Isotopes_of_platinum#List_of_isotopes" title="Isotopes of platinum">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Platinum" title="Platinum">Pt</a></b></div>78 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_gold" title="Isotopes of gold">Isotopes</a>  <a href="/wiki/Isotopes_of_gold#List_of_isotopes" title="Isotopes of gold">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Gold" title="Gold">Au</a></b></div>79 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_mercury" title="Isotopes of mercury">Isotopes</a>  <a href="/wiki/Isotopes_of_mercury#List_of_isotopes" title="Isotopes of mercury">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Mercury_(element)" title="Mercury (element)">Hg</a></b></div>80 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_thallium" title="Isotopes of thallium">Isotopes</a>  <a href="/wiki/Isotopes_of_thallium#List_of_isotopes" title="Isotopes of thallium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Thallium" title="Thallium">Tl</a></b></div>81 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_lead" title="Isotopes of lead">Isotopes</a>  <a href="/wiki/Isotopes_of_lead#List_of_isotopes" title="Isotopes of lead">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Lead" title="Lead">Pb</a></b></div>82 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_bismuth" title="Isotopes of bismuth">Isotopes</a>  <a href="/wiki/Isotopes_of_bismuth#List_of_isotopes" title="Isotopes of bismuth">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Bismuth" title="Bismuth">Bi</a></b></div>83 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_polonium" title="Isotopes of polonium">Isotopes</a>  <a href="/wiki/Isotopes_of_polonium#List_of_isotopes" title="Isotopes of polonium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Polonium" title="Polonium">Po</a></b></div>84 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_astatine" title="Isotopes of astatine">Isotopes</a>  <a href="/wiki/Isotopes_of_astatine#List_of_isotopes" title="Isotopes of astatine">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Astatine" title="Astatine">At</a></b></div>85 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_radon" title="Isotopes of radon">Isotopes</a>  <a href="/wiki/Isotopes_of_radon#List_of_isotopes" title="Isotopes of radon">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Radon" title="Radon">Rn</a></b></div>86 </td></tr> <tr> <th style="background:transparent"><span title="Period ⑦" class="nounderlines" style="font-size:150%;"><a href="/wiki/Period_7_element" title="Period 7 element">⑦</a></span> </th> <td style="padding-left:0.1em; background:#ff9999;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_francium" title="Isotopes of francium">Isotopes</a>  <a href="/wiki/Isotopes_of_francium#List_of_isotopes" title="Isotopes of francium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Francium" title="Francium">Fr</a></b></div>87 </td> <td style="padding-left:0.1em; background:#ff9999;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_radium" title="Isotopes of radium">Isotopes</a>  <a href="/wiki/Isotopes_of_radium#List_of_isotopes" title="Isotopes of radium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Radium" title="Radium">Ra</a></b></div>88 </td> <td style="text-align:center; vertical-align:middle; background:#9bff99;"><span class="skin-invert-image" typeof="mw:File"><span><img alt="1 asterisk" src="//upload.wikimedia.org/wikipedia/commons/thumb/f/fe/Asterisks_2_%28vertical%29.svg/16px-Asterisks_2_%28vertical%29.svg.png" decoding="async" width="16" height="15" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/f/fe/Asterisks_2_%28vertical%29.svg/24px-Asterisks_2_%28vertical%29.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/f/fe/Asterisks_2_%28vertical%29.svg/32px-Asterisks_2_%28vertical%29.svg.png 2x" data-file-width="106" data-file-height="98" /></span></span> </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_lawrencium" title="Isotopes of lawrencium">Isotopes</a>  <a href="/wiki/Isotopes_of_lawrencium#List_of_isotopes" title="Isotopes of lawrencium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Lawrencium" title="Lawrencium">Lr</a></b></div>103 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_rutherfordium" title="Isotopes of rutherfordium">Isotopes</a>  <a href="/wiki/Isotopes_of_rutherfordium#List_of_isotopes" title="Isotopes of rutherfordium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Rutherfordium" title="Rutherfordium">Rf</a></b></div>104 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_dubnium" title="Isotopes of dubnium">Isotopes</a>  <a href="/wiki/Isotopes_of_dubnium#List_of_isotopes" title="Isotopes of dubnium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Dubnium" title="Dubnium">Db</a></b></div>105 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_seaborgium" title="Isotopes of seaborgium">Isotopes</a>  <a href="/wiki/Isotopes_of_seaborgium#List_of_isotopes" title="Isotopes of seaborgium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Seaborgium" title="Seaborgium">Sg</a></b></div>106 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_bohrium" title="Isotopes of bohrium">Isotopes</a>  <a href="/wiki/Isotopes_of_bohrium#List_of_isotopes" title="Isotopes of bohrium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Bohrium" title="Bohrium">Bh</a></b></div>107 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_hassium" title="Isotopes of hassium">Isotopes</a>  <a href="/wiki/Isotopes_of_hassium#List_of_isotopes" title="Isotopes of hassium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Hassium" title="Hassium">Hs</a></b></div>108 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_meitnerium" title="Isotopes of meitnerium">Isotopes</a>  <a href="/wiki/Isotopes_of_meitnerium#List_of_isotopes" title="Isotopes of meitnerium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Meitnerium" title="Meitnerium">Mt</a></b></div>109 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_darmstadtium" title="Isotopes of darmstadtium">Isotopes</a>  <a href="/wiki/Isotopes_of_darmstadtium#List_of_isotopes" title="Isotopes of darmstadtium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Darmstadtium" title="Darmstadtium">Ds</a></b></div>110 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_roentgenium" title="Isotopes of roentgenium">Isotopes</a>  <a href="/wiki/Isotopes_of_roentgenium#List_of_isotopes" title="Isotopes of roentgenium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Roentgenium" title="Roentgenium">Rg</a></b></div>111 </td> <td style="padding-left:0.1em; background:#99ccff;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_copernicium" title="Isotopes of copernicium">Isotopes</a>  <a href="/wiki/Isotopes_of_copernicium#List_of_isotopes" title="Isotopes of copernicium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Copernicium" title="Copernicium">Cn</a></b></div>112 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_nihonium" title="Isotopes of nihonium">Isotopes</a>  <a href="/wiki/Isotopes_of_nihonium#List_of_isotopes" title="Isotopes of nihonium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Nihonium" title="Nihonium">Nh</a></b></div>113 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_flerovium" title="Isotopes of flerovium">Isotopes</a>  <a href="/wiki/Isotopes_of_flerovium#List_of_isotopes" title="Isotopes of flerovium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Flerovium" title="Flerovium">Fl</a></b></div>114 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_moscovium" title="Isotopes of moscovium">Isotopes</a>  <a href="/wiki/Isotopes_of_moscovium#List_of_isotopes" title="Isotopes of moscovium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Moscovium" title="Moscovium">Mc</a></b></div>115 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_livermorium" title="Isotopes of livermorium">Isotopes</a>  <a href="/wiki/Isotopes_of_livermorium#List_of_isotopes" title="Isotopes of livermorium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Livermorium" title="Livermorium">Lv</a></b></div>116 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_tennessine" title="Isotopes of tennessine">Isotopes</a>  <a href="/wiki/Isotopes_of_tennessine#List_of_isotopes" title="Isotopes of tennessine">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Tennessine" title="Tennessine">Ts</a></b></div>117 </td> <td style="padding-left:0.1em; background:#fdff8c;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_oganesson" title="Isotopes of oganesson">Isotopes</a>  <a href="/wiki/Isotopes_of_oganesson#List_of_isotopes" title="Isotopes of oganesson">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Oganesson" title="Oganesson">Og</a></b></div>118 </td></tr> <tr> <th style="background:transparent"><span title="Period ⑧" class="nounderlines" style="font-size:150%;"><a href="/wiki/Period_8_element" class="mw-redirect" title="Period 8 element">⑧</a></span> </th> <td style="padding-left:0.1em; background:#eee;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_ununennium" title="Isotopes of ununennium">Isotopes</a>  <a href="/wiki/Isotopes_of_ununennium#List_of_isotopes" title="Isotopes of ununennium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Ununennium" title="Ununennium">Uue</a></b></div>119 </td> <td style="padding-left:0.1em; background:#eee;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_unbinilium" title="Isotopes of unbinilium">Isotopes</a>  <a href="/wiki/Isotopes_of_unbinilium#List_of_isotopes" title="Isotopes of unbinilium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Unbinilium" title="Unbinilium">Ubn</a></b></div>120 </td></tr> <tr> <td colspan="20" style="height:1.4em;"> </td></tr> <tr> <td> </td> <td> </td> <td> </td> <td style="text-align:center; vertical-align:middle;"><span class="skin-invert-image" typeof="mw:File"><span><img alt="1 asterisk" src="//upload.wikimedia.org/wikipedia/commons/thumb/4/49/Asterisks_one.svg/16px-Asterisks_one.svg.png" decoding="async" width="16" height="15" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/49/Asterisks_one.svg/24px-Asterisks_one.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/49/Asterisks_one.svg/32px-Asterisks_one.svg.png 2x" data-file-width="106" data-file-height="98" /></span></span> </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_lanthanum" title="Isotopes of lanthanum">Isotopes</a>  <a href="/wiki/Isotopes_of_lanthanum#List_of_isotopes" title="Isotopes of lanthanum">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Lanthanum" title="Lanthanum">La</a></b></div>57 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_cerium" title="Isotopes of cerium">Isotopes</a>  <a href="/wiki/Isotopes_of_cerium#List_of_isotopes" title="Isotopes of cerium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Cerium" title="Cerium">Ce</a></b></div>58 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_praseodymium" title="Isotopes of praseodymium">Isotopes</a>  <a href="/wiki/Isotopes_of_praseodymium#List_of_isotopes" title="Isotopes of praseodymium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Praseodymium" title="Praseodymium">Pr</a></b></div>59 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_neodymium" title="Isotopes of neodymium">Isotopes</a>  <a href="/wiki/Isotopes_of_neodymium#List_of_isotopes" title="Isotopes of neodymium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Neodymium" title="Neodymium">Nd</a></b></div>60 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_promethium" title="Isotopes of promethium">Isotopes</a>  <a href="/wiki/Isotopes_of_promethium#List_of_isotopes" title="Isotopes of promethium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Promethium" title="Promethium">Pm</a></b></div>61 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_samarium" title="Isotopes of samarium">Isotopes</a>  <a href="/wiki/Isotopes_of_samarium#List_of_isotopes" title="Isotopes of samarium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Samarium" title="Samarium">Sm</a></b></div>62 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_europium" title="Isotopes of europium">Isotopes</a>  <a href="/wiki/Isotopes_of_europium#List_of_isotopes" title="Isotopes of europium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Europium" title="Europium">Eu</a></b></div>63 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_gadolinium" title="Isotopes of gadolinium">Isotopes</a>  <a href="/wiki/Isotopes_of_gadolinium#List_of_isotopes" title="Isotopes of gadolinium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Gadolinium" title="Gadolinium">Gd</a></b></div>64 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_terbium" title="Isotopes of terbium">Isotopes</a>  <a href="/wiki/Isotopes_of_terbium#List_of_isotopes" title="Isotopes of terbium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Terbium" title="Terbium">Tb</a></b></div>65 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_dysprosium" title="Isotopes of dysprosium">Isotopes</a>  <a href="/wiki/Isotopes_of_dysprosium#List_of_isotopes" title="Isotopes of dysprosium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Dysprosium" title="Dysprosium">Dy</a></b></div>66 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_holmium" title="Isotopes of holmium">Isotopes</a>  <a href="/wiki/Isotopes_of_holmium#List_of_isotopes" title="Isotopes of holmium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Holmium" title="Holmium">Ho</a></b></div>67 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_erbium" title="Isotopes of erbium">Isotopes</a>  <a href="/wiki/Isotopes_of_erbium#List_of_isotopes" title="Isotopes of erbium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Erbium" title="Erbium">Er</a></b></div>68 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_thulium" title="Isotopes of thulium">Isotopes</a>  <a href="/wiki/Isotopes_of_thulium#List_of_isotopes" title="Isotopes of thulium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Thulium" title="Thulium">Tm</a></b></div>69 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_ytterbium" title="Isotopes of ytterbium">Isotopes</a>  <a href="/wiki/Isotopes_of_ytterbium#List_of_isotopes" title="Isotopes of ytterbium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Ytterbium" title="Ytterbium">Yb</a></b></div>70 </td> <td>  </td></tr> <tr> <td colspan="3"> </td> <td style="text-align:center; vertical-align:middle;"><span class="skin-invert-image" typeof="mw:File"><span><img alt="1 asterisk" src="//upload.wikimedia.org/wikipedia/commons/thumb/f/fe/Asterisks_2_%28vertical%29.svg/16px-Asterisks_2_%28vertical%29.svg.png" decoding="async" width="16" height="15" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/f/fe/Asterisks_2_%28vertical%29.svg/24px-Asterisks_2_%28vertical%29.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/f/fe/Asterisks_2_%28vertical%29.svg/32px-Asterisks_2_%28vertical%29.svg.png 2x" data-file-width="106" data-file-height="98" /></span></span> </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_actinium" title="Isotopes of actinium">Isotopes</a>  <a href="/wiki/Isotopes_of_actinium#List_of_isotopes" title="Isotopes of actinium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Actinium" title="Actinium">Ac</a></b></div>89 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_thorium" title="Isotopes of thorium">Isotopes</a>  <a href="/wiki/Isotopes_of_thorium#List_of_isotopes" title="Isotopes of thorium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Thorium" title="Thorium">Th</a></b></div>90 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_protactinium" title="Isotopes of protactinium">Isotopes</a>  <a href="/wiki/Isotopes_of_protactinium#List_of_isotopes" title="Isotopes of protactinium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Protactinium" title="Protactinium">Pa</a></b></div>91 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_uranium" title="Isotopes of uranium">Isotopes</a>  <a href="/wiki/Isotopes_of_uranium#List_of_isotopes" title="Isotopes of uranium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Uranium" title="Uranium">U</a></b></div>92 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_neptunium" title="Isotopes of neptunium">Isotopes</a>  <a href="/wiki/Isotopes_of_neptunium#List_of_isotopes" title="Isotopes of neptunium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Neptunium" title="Neptunium">Np</a></b></div>93 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_plutonium" title="Isotopes of plutonium">Isotopes</a>  <a href="/wiki/Isotopes_of_plutonium#List_of_isotopes" title="Isotopes of plutonium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Plutonium" title="Plutonium">Pu</a></b></div>94 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_americium" title="Isotopes of americium">Isotopes</a>  <a href="/wiki/Isotopes_of_americium#List_of_isotopes" title="Isotopes of americium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Americium" title="Americium">Am</a></b></div>95 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_curium" title="Isotopes of curium">Isotopes</a>  <a href="/wiki/Isotopes_of_curium#List_of_isotopes" title="Isotopes of curium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Curium" title="Curium">Cm</a></b></div>96 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_berkelium" title="Isotopes of berkelium">Isotopes</a>  <a href="/wiki/Isotopes_of_berkelium#List_of_isotopes" title="Isotopes of berkelium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Berkelium" title="Berkelium">Bk</a></b></div>97 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_californium" title="Isotopes of californium">Isotopes</a>  <a href="/wiki/Isotopes_of_californium#List_of_isotopes" title="Isotopes of californium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Californium" title="Californium">Cf</a></b></div>98 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_einsteinium" title="Isotopes of einsteinium">Isotopes</a>  <a href="/wiki/Isotopes_of_einsteinium#List_of_isotopes" title="Isotopes of einsteinium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Einsteinium" title="Einsteinium">Es</a></b></div>99 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_fermium" title="Isotopes of fermium">Isotopes</a>  <a href="/wiki/Isotopes_of_fermium#List_of_isotopes" title="Isotopes of fermium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Fermium" title="Fermium">Fm</a></b></div>100 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_mendelevium" title="Isotopes of mendelevium">Isotopes</a>  <a href="/wiki/Isotopes_of_mendelevium#List_of_isotopes" title="Isotopes of mendelevium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Mendelevium" title="Mendelevium">Md</a></b></div>101 </td> <td style="padding-left:0.1em; background:#9bff99;"><div style="text-align:left"><small><a href="/wiki/Isotopes_of_nobelium" title="Isotopes of nobelium">Isotopes</a>  <a href="/wiki/Isotopes_of_nobelium#List_of_isotopes" title="Isotopes of nobelium">§ List</a></small></div><div style="display:block"><b><a href="/wiki/Nobelium" title="Nobelium">No</a></b></div>102 </td></tr></tbody></table> </div></td></tr><tr><td class="navbox-abovebelow hlist" colspan="2" style="background:#f0f0f0;"><div> <ul><li><a href="/wiki/Table_of_nuclides" title="Table of nuclides">Table of nuclides</a></li> <li>Categories: <a href="/wiki/Category:Isotopes" title="Category:Isotopes">Isotopes</a></li> <li><a href="/wiki/Category:Tables_of_nuclides" title="Category:Tables of nuclides">Tables of nuclides</a></li> <li><a href="/wiki/Category:Metastable_isotopes" title="Category:Metastable isotopes">Metastable isotopes</a></li> <li><a href="/wiki/Category:Lists_of_isotopes_by_element" title="Category:Lists of isotopes by element">Isotopes by element</a></li></ul> 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srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/20px-OOjs_UI_icon_edit-ltr-progressive.svg.png 2x" data-file-width="20" data-file-height="20" /></a></span></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%">National</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"><ul><li><span class="uid"><span class="rt-commentedText tooltip tooltip-dotted" title="Isotop"><a rel="nofollow" class="external text" href="https://d-nb.info/gnd/4027801-3">Germany</a></span></span></li><li><span class="uid"><a rel="nofollow" class="external text" href="https://id.loc.gov/authorities/sh00006433">United States</a></span></li><li><span class="uid"><span class="rt-commentedText tooltip tooltip-dotted" title="Isotopes"><a rel="nofollow" class="external text" href="https://catalogue.bnf.fr/ark:/12148/cb119764167">France</a></span></span></li><li><span class="uid"><span class="rt-commentedText tooltip tooltip-dotted" title="Isotopes"><a rel="nofollow" class="external text" href="https://data.bnf.fr/ark:/12148/cb119764167">BnF data</a></span></span></li><li><span class="uid"><a rel="nofollow" class="external text" href="https://id.ndl.go.jp/auth/ndlna/00561570">Japan</a></span></li><li><span class="uid"><span class="rt-commentedText tooltip tooltip-dotted" title="izotopy"><a rel="nofollow" class="external text" href="https://aleph.nkp.cz/F/?func=find-c&local_base=aut&ccl_term=ica=ph121258&CON_LNG=ENG">Czech Republic</a></span></span></li><li><span class="uid"><a rel="nofollow" class="external text" href="https://kopkatalogs.lv/F?func=direct&local_base=lnc10&doc_number=000126006&P_CON_LNG=ENG">Latvia</a></span></li><li><span class="uid"><a rel="nofollow" class="external text" href="http://olduli.nli.org.il/F/?func=find-b&local_base=NLX10&find_code=UID&request=987007292873705171">Israel</a></span></li></ul></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Other</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"><ul><li><span class="uid"><a rel="nofollow" class="external text" href="http://esu.com.ua/search_articles.php?id=13850">Encyclopedia of Modern Ukraine</a></span></li></ul></div></td></tr></tbody></table></div>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?type=1x1" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Retrieved from "<a dir="ltr" href="https://en.wikipedia.org/w/index.php?title=Isotope&oldid=1257078527">https://en.wikipedia.org/w/index.php?title=Isotope&oldid=1257078527</a>"</div></div> <div id="catlinks" class="catlinks" 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