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Unità di massa atomica - Wikipedia
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class="vector-toc-list"> </ul> </li> <li id="toc-Simboli" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Simboli"> <div class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>Simboli</span> </div> </a> <ul id="toc-Simboli-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Fattori_di_conversione" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Fattori_di_conversione"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Fattori di conversione</span> </div> </a> <ul id="toc-Fattori_di_conversione-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Storia" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Storia"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>Storia</span> </div> </a> <ul id="toc-Storia-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Relazione_con_il_sistema_internazionale" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Relazione_con_il_sistema_internazionale"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>Relazione con il sistema internazionale</span> </div> </a> <ul id="toc-Relazione_con_il_sistema_internazionale-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Note" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Note"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>Note</span> </div> </a> <ul id="toc-Note-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Bibliografia" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Bibliografia"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>Bibliografia</span> </div> </a> <ul id="toc-Bibliografia-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Voci_correlate" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Voci_correlate"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>Voci correlate</span> </div> </a> <ul id="toc-Voci_correlate-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Collegamenti_esterni" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Collegamenti_esterni"> <div class="vector-toc-text"> <span class="vector-toc-numb">9</span> <span>Collegamenti esterni</span> </div> </a> <ul id="toc-Collegamenti_esterni-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="Indice" 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="Mostra/Nascondi l'indice" > <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">Mostra/Nascondi l'indice</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">Unità di massa atomica</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="Vai a una voce in un'altra lingua. Disponibile in 76 lingue" > <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-76" 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">76 lingue</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/Dalton_(eenheid)" title="Dalton (eenheid) - afrikaans" lang="af" hreflang="af" data-title="Dalton (eenheid)" 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%88%D8%AD%D8%AF%D8%A9_%D9%83%D8%AA%D9%84_%D8%B0%D8%B1%D9%8A%D8%A9" title="وحدة كتل ذرية - arabo" lang="ar" hreflang="ar" data-title="وحدة كتل ذرية" data-language-autonym="العربية" data-language-local-name="arabo" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-ast mw-list-item"><a href="https://ast.wikipedia.org/wiki/Unid%C3%A1_de_masa_at%C3%B3mica" title="Unidá de masa atómica - asturiano" lang="ast" hreflang="ast" data-title="Unidá de masa atómica" data-language-autonym="Asturianu" data-language-local-name="asturiano" class="interlanguage-link-target"><span>Asturianu</span></a></li><li class="interlanguage-link interwiki-ba mw-list-item"><a href="https://ba.wikipedia.org/wiki/%D0%9C%D0%B0%D1%81%D1%81%D0%B0%D0%BD%D1%8B%D2%A3_%D0%B0%D1%82%D0%BE%D0%BC_%D0%B1%D0%B5%D1%80%D3%99%D0%BC%D0%B5%D0%B3%D0%B5" title="Массаның атом берәмеге - baschiro" lang="ba" hreflang="ba" data-title="Массаның атом берәмеге" data-language-autonym="Башҡортса" data-language-local-name="baschiro" class="interlanguage-link-target"><span>Башҡортса</span></a></li><li class="interlanguage-link interwiki-be mw-list-item"><a href="https://be.wikipedia.org/wiki/%D0%90%D1%82%D0%B0%D0%BC%D0%BD%D0%B0%D1%8F_%D0%B0%D0%B4%D0%B7%D1%96%D0%BD%D0%BA%D0%B0_%D0%BC%D0%B0%D1%81%D1%8B" title="Атамная адзінка масы - bielorusso" lang="be" hreflang="be" data-title="Атамная адзінка масы" data-language-autonym="Беларуская" data-language-local-name="bielorusso" class="interlanguage-link-target"><span>Беларуская</span></a></li><li class="interlanguage-link interwiki-bg mw-list-item"><a href="https://bg.wikipedia.org/wiki/%D0%95%D0%B4%D0%B8%D0%BD%D0%B8%D1%86%D0%B0_%D0%B7%D0%B0_%D0%B0%D1%82%D0%BE%D0%BC%D0%BD%D0%B0_%D0%BC%D0%B0%D1%81%D0%B0" title="Единица за атомна маса - bulgaro" lang="bg" hreflang="bg" data-title="Единица за атомна маса" data-language-autonym="Български" data-language-local-name="bulgaro" class="interlanguage-link-target"><span>Български</span></a></li><li class="interlanguage-link interwiki-bn mw-list-item"><a href="https://bn.wikipedia.org/wiki/%E0%A6%A1%E0%A6%BE%E0%A6%B2%E0%A7%8D%E0%A6%9F%E0%A6%A8_(%E0%A6%8F%E0%A6%95%E0%A6%95)" title="ডাল্টন (একক) - bengalese" lang="bn" hreflang="bn" data-title="ডাল্টন (একক)" data-language-autonym="বাংলা" data-language-local-name="bengalese" class="interlanguage-link-target"><span>বাংলা</span></a></li><li class="interlanguage-link interwiki-bo mw-list-item"><a href="https://bo.wikipedia.org/wiki/%E0%BD%A2%E0%BE%A1%E0%BD%B4%E0%BD%A3%E0%BC%8B%E0%BD%95%E0%BE%B2%E0%BD%93%E0%BC%8B%E0%BD%A6%E0%BE%A4%E0%BD%B4%E0%BD%A6%E0%BC%8B%E0%BD%9A%E0%BD%91%E0%BC%8B%E0%BD%A2%E0%BE%A9%E0%BD%B2%E0%BC%8B%E0%BD%82%E0%BD%9E%E0%BD%B2%E0%BC%8D" title="རྡུལ་ཕྲན་སྤུས་ཚད་རྩི་གཞི། - tibetano" lang="bo" hreflang="bo" data-title="རྡུལ་ཕྲན་སྤུས་ཚད་རྩི་གཞི།" data-language-autonym="བོད་ཡིག" data-language-local-name="tibetano" class="interlanguage-link-target"><span>བོད་ཡིག</span></a></li><li class="interlanguage-link interwiki-br mw-list-item"><a href="https://br.wikipedia.org/wiki/Unanenn_vas_atomek" title="Unanenn vas atomek - bretone" lang="br" hreflang="br" data-title="Unanenn vas atomek" data-language-autonym="Brezhoneg" data-language-local-name="bretone" class="interlanguage-link-target"><span>Brezhoneg</span></a></li><li class="interlanguage-link interwiki-bs mw-list-item"><a href="https://bs.wikipedia.org/wiki/Jedinica_atomske_mase" title="Jedinica atomske mase - bosniaco" lang="bs" hreflang="bs" data-title="Jedinica atomske mase" data-language-autonym="Bosanski" data-language-local-name="bosniaco" class="interlanguage-link-target"><span>Bosanski</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Unitat_de_massa_at%C3%B2mica" title="Unitat de massa atòmica - catalano" lang="ca" hreflang="ca" data-title="Unitat de massa atòmica" data-language-autonym="Català" data-language-local-name="catalano" 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%9C%D0%B0%D1%81%D1%81%C4%83%D0%BD_%D0%B0%D1%82%D0%BE%D0%BC%D0%BB%D0%B0_%D0%BF%C4%95%D1%80%D1%87%D0%B8" title="Массăн атомла пĕрчи - ciuvascio" lang="cv" hreflang="cv" data-title="Массăн атомла пĕрчи" data-language-autonym="Чӑвашла" data-language-local-name="ciuvascio" class="interlanguage-link-target"><span>Чӑвашла</span></a></li><li class="interlanguage-link interwiki-cy mw-list-item"><a href="https://cy.wikipedia.org/wiki/Uned_Dalton" title="Uned Dalton - gallese" lang="cy" hreflang="cy" data-title="Uned Dalton" data-language-autonym="Cymraeg" data-language-local-name="gallese" 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/Atommasseenhed" title="Atommasseenhed - danese" lang="da" hreflang="da" data-title="Atommasseenhed" data-language-autonym="Dansk" data-language-local-name="danese" class="interlanguage-link-target"><span>Dansk</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Atomare_Masseneinheit" title="Atomare Masseneinheit - tedesco" lang="de" hreflang="de" data-title="Atomare Masseneinheit" data-language-autonym="Deutsch" data-language-local-name="tedesco" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-el mw-list-item"><a href="https://el.wikipedia.org/wiki/%CE%91%CF%84%CE%BF%CE%BC%CE%B9%CE%BA%CE%AE_%CE%BC%CE%BF%CE%BD%CE%AC%CE%B4%CE%B1_%CE%BC%CE%AC%CE%B6%CE%B1%CF%82" title="Ατομική μονάδα μάζας - greco" lang="el" hreflang="el" data-title="Ατομική μονάδα μάζας" data-language-autonym="Ελληνικά" data-language-local-name="greco" class="interlanguage-link-target"><span>Ελληνικά</span></a></li><li class="interlanguage-link interwiki-en mw-list-item"><a href="https://en.wikipedia.org/wiki/Dalton_(unit)" title="Dalton (unit) - inglese" lang="en" hreflang="en" data-title="Dalton (unit)" data-language-autonym="English" data-language-local-name="inglese" class="interlanguage-link-target"><span>English</span></a></li><li class="interlanguage-link interwiki-eo mw-list-item"><a href="https://eo.wikipedia.org/wiki/Atommasa_unuo" title="Atommasa unuo - esperanto" lang="eo" hreflang="eo" data-title="Atommasa unuo" data-language-autonym="Esperanto" data-language-local-name="esperanto" class="interlanguage-link-target"><span>Esperanto</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Unidad_de_masa_at%C3%B3mica" title="Unidad de masa atómica - spagnolo" lang="es" hreflang="es" data-title="Unidad de masa atómica" data-language-autonym="Español" data-language-local-name="spagnolo" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-et mw-list-item"><a href="https://et.wikipedia.org/wiki/Aatommassi%C3%BChik" title="Aatommassiühik - estone" lang="et" hreflang="et" data-title="Aatommassiühik" data-language-autonym="Eesti" data-language-local-name="estone" class="interlanguage-link-target"><span>Eesti</span></a></li><li class="interlanguage-link interwiki-eu mw-list-item"><a href="https://eu.wikipedia.org/wiki/Masa_atomikoaren_unitate" title="Masa atomikoaren unitate - basco" lang="eu" hreflang="eu" data-title="Masa atomikoaren unitate" data-language-autonym="Euskara" data-language-local-name="basco" 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/%DB%8C%DA%A9%D8%A7%DB%8C_%D8%AC%D8%B1%D9%85_%D8%A7%D8%AA%D9%85%DB%8C" title="یکای جرم اتمی - persiano" lang="fa" hreflang="fa" data-title="یکای جرم اتمی" data-language-autonym="فارسی" data-language-local-name="persiano" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/Atomimassayksikk%C3%B6" title="Atomimassayksikkö - finlandese" lang="fi" hreflang="fi" data-title="Atomimassayksikkö" data-language-autonym="Suomi" data-language-local-name="finlandese" class="interlanguage-link-target"><span>Suomi</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/Unit%C3%A9_de_masse_atomique_unifi%C3%A9e" title="Unité de masse atomique unifiée - francese" lang="fr" hreflang="fr" data-title="Unité de masse atomique unifiée" data-language-autonym="Français" data-language-local-name="francese" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-frr mw-list-item"><a href="https://frr.wikipedia.org/wiki/Atomaar_masenianhaid" title="Atomaar masenianhaid - frisone settentrionale" lang="frr" hreflang="frr" data-title="Atomaar masenianhaid" data-language-autonym="Nordfriisk" data-language-local-name="frisone settentrionale" class="interlanguage-link-target"><span>Nordfriisk</span></a></li><li class="interlanguage-link interwiki-fy mw-list-item"><a href="https://fy.wikipedia.org/wiki/Atom%C3%AAre_massa-ienheid" title="Atomêre massa-ienheid - frisone occidentale" lang="fy" hreflang="fy" data-title="Atomêre massa-ienheid" data-language-autonym="Frysk" data-language-local-name="frisone occidentale" class="interlanguage-link-target"><span>Frysk</span></a></li><li class="interlanguage-link interwiki-ga mw-list-item"><a href="https://ga.wikipedia.org/wiki/Aonad_maise_adamha%C3%AD" title="Aonad maise adamhaí - irlandese" lang="ga" hreflang="ga" data-title="Aonad maise adamhaí" data-language-autonym="Gaeilge" data-language-local-name="irlandese" 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/Unidade_de_masa_at%C3%B3mica" title="Unidade de masa atómica - galiziano" lang="gl" hreflang="gl" data-title="Unidade de masa atómica" data-language-autonym="Galego" data-language-local-name="galiziano" class="interlanguage-link-target"><span>Galego</span></a></li><li class="interlanguage-link interwiki-he mw-list-item"><a href="https://he.wikipedia.org/wiki/%D7%99%D7%97%D7%99%D7%93%D7%AA_%D7%9E%D7%A1%D7%94_%D7%90%D7%98%D7%95%D7%9E%D7%99%D7%AA_%D7%9E%D7%90%D7%95%D7%97%D7%93%D7%AA" title="יחידת מסה אטומית מאוחדת - ebraico" lang="he" hreflang="he" data-title="יחידת מסה אטומית מאוחדת" data-language-autonym="עברית" data-language-local-name="ebraico" class="interlanguage-link-target"><span>עברית</span></a></li><li class="interlanguage-link interwiki-hi mw-list-item"><a href="https://hi.wikipedia.org/wiki/%E0%A4%8F%E0%A4%95%E0%A5%80%E0%A4%95%E0%A5%83%E0%A4%A4_%E0%A4%AA%E0%A4%B0%E0%A4%AE%E0%A4%BE%E0%A4%A3%E0%A5%8D%E0%A4%B5%E0%A5%80%E0%A4%AF_%E0%A4%A6%E0%A5%8D%E0%A4%B0%E0%A4%B5%E0%A5%8D%E0%A4%AF%E0%A4%AE%E0%A4%BE%E0%A4%A8_%E0%A4%AE%E0%A4%BE%E0%A4%A4%E0%A5%8D%E0%A4%B0%E0%A4%95" title="एकीकृत परमाण्वीय द्रव्यमान मात्रक - hindi" lang="hi" hreflang="hi" data-title="एकीकृत परमाण्वीय द्रव्यमान मात्रक" 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/Atomska_jedinica_mase" title="Atomska jedinica mase - croato" lang="hr" hreflang="hr" data-title="Atomska jedinica mase" data-language-autonym="Hrvatski" data-language-local-name="croato" class="interlanguage-link-target"><span>Hrvatski</span></a></li><li class="interlanguage-link interwiki-hu mw-list-item"><a href="https://hu.wikipedia.org/wiki/Atomi_t%C3%B6megegys%C3%A9g" title="Atomi tömegegység - ungherese" lang="hu" hreflang="hu" data-title="Atomi tömegegység" data-language-autonym="Magyar" data-language-local-name="ungherese" class="interlanguage-link-target"><span>Magyar</span></a></li><li class="interlanguage-link interwiki-hy mw-list-item"><a href="https://hy.wikipedia.org/wiki/%D4%B6%D5%A1%D5%B6%D5%A3%D5%BE%D5%A1%D5%AE%D5%AB_%D5%A1%D5%BF%D5%B8%D5%B4%D5%A1%D5%AF%D5%A1%D5%B6_%D5%B4%D5%AB%D5%A1%D5%BE%D5%B8%D6%80" title="Զանգվածի ատոմական միավոր - armeno" lang="hy" hreflang="hy" data-title="Զանգվածի ատոմական միավոր" data-language-autonym="Հայերեն" data-language-local-name="armeno" class="interlanguage-link-target"><span>Հայերեն</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Dalton_(satuan)" title="Dalton (satuan) - indonesiano" lang="id" hreflang="id" data-title="Dalton (satuan)" data-language-autonym="Bahasa Indonesia" data-language-local-name="indonesiano" class="interlanguage-link-target"><span>Bahasa Indonesia</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%E7%B5%B1%E4%B8%80%E5%8E%9F%E5%AD%90%E8%B3%AA%E9%87%8F%E5%8D%98%E4%BD%8D" title="統一原子質量単位 - giapponese" lang="ja" hreflang="ja" data-title="統一原子質量単位" data-language-autonym="日本語" data-language-local-name="giapponese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-ka mw-list-item"><a href="https://ka.wikipedia.org/wiki/%E1%83%9B%E1%83%90%E1%83%A1%E1%83%98%E1%83%A1_%E1%83%90%E1%83%A2%E1%83%9D%E1%83%9B%E1%83%A3%E1%83%A0%E1%83%98_%E1%83%94%E1%83%A0%E1%83%97%E1%83%94%E1%83%A3%E1%83%9A%E1%83%98" title="მასის ატომური ერთეული - georgiano" lang="ka" hreflang="ka" data-title="მასის ატომური ერთეული" data-language-autonym="ქართული" data-language-local-name="georgiano" 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%9C%D0%B0%D1%81%D1%81%D0%B0%D0%BD%D1%8B%D2%A3_%D0%B0%D1%82%D0%BE%D0%BC%D0%B4%D1%8B%D2%9B_%D0%B1%D1%96%D1%80%D0%BB%D1%96%D0%B3%D1%96" title="Массаның атомдық бірлігі - kazako" lang="kk" hreflang="kk" data-title="Массаның атомдық бірлігі" data-language-autonym="Қазақша" data-language-local-name="kazako" class="interlanguage-link-target"><span>Қазақша</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/%EC%9B%90%EC%9E%90_%EC%A7%88%EB%9F%89_%EB%8B%A8%EC%9C%84" title="원자 질량 단위 - coreano" lang="ko" hreflang="ko" data-title="원자 질량 단위" data-language-autonym="한국어" data-language-local-name="coreano" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-lt mw-list-item"><a href="https://lt.wikipedia.org/wiki/Atomin%C4%97s_mas%C4%97s_vienetas" title="Atominės masės vienetas - lituano" lang="lt" hreflang="lt" data-title="Atominės masės vienetas" data-language-autonym="Lietuvių" data-language-local-name="lituano" class="interlanguage-link-target"><span>Lietuvių</span></a></li><li class="interlanguage-link interwiki-lv mw-list-item"><a href="https://lv.wikipedia.org/wiki/Atommasas_vien%C4%ABba" title="Atommasas vienība - lettone" lang="lv" hreflang="lv" data-title="Atommasas vienība" data-language-autonym="Latviešu" data-language-local-name="lettone" class="interlanguage-link-target"><span>Latviešu</span></a></li><li class="interlanguage-link interwiki-mdf mw-list-item"><a href="https://mdf.wikipedia.org/wiki/%D0%A1%D1%82%D0%B0%D0%BB%D0%BC%D0%BE%D1%81%D1%82%D1%8C_%D0%B0%D1%82%D0%BE%D0%BC%D0%BE%D0%BD%D1%8C_%D0%B5%D0%B4%D0%B8%D0%BD%D0%B8%D1%86%D0%B0%D1%86" title="Сталмость атомонь единицац - moksha" lang="mdf" hreflang="mdf" data-title="Сталмость атомонь единицац" data-language-autonym="Мокшень" data-language-local-name="moksha" class="interlanguage-link-target"><span>Мокшень</span></a></li><li class="interlanguage-link interwiki-mk mw-list-item"><a href="https://mk.wikipedia.org/wiki/%D0%90%D1%82%D0%BE%D0%BC%D1%81%D0%BA%D0%B0_%D0%B5%D0%B4%D0%B8%D0%BD%D0%B8%D1%86%D0%B0_%D0%B7%D0%B0_%D0%BC%D0%B0%D1%81%D0%B0" title="Атомска единица за маса - macedone" lang="mk" hreflang="mk" data-title="Атомска единица за маса" data-language-autonym="Македонски" data-language-local-name="macedone" class="interlanguage-link-target"><span>Македонски</span></a></li><li class="interlanguage-link interwiki-ml mw-list-item"><a href="https://ml.wikipedia.org/wiki/%E0%B4%85%E0%B4%B1%E0%B5%8D%E0%B4%B1%E0%B5%8B%E0%B4%AE%E0%B4%BF%E0%B4%95%E0%B5%8D_%E0%B4%AE%E0%B4%BE%E0%B4%B8%E0%B5%8D%E0%B4%B8%E0%B5%8D_%E0%B4%AF%E0%B5%82%E0%B4%A3%E0%B4%BF%E0%B4%B1%E0%B5%8D%E0%B4%B1%E0%B5%8D" title="അറ്റോമിക് മാസ്സ് യൂണിറ്റ് - malayalam" lang="ml" hreflang="ml" data-title="അറ്റോമിക് മാസ്സ് യൂണിറ്റ്" data-language-autonym="മലയാളം" data-language-local-name="malayalam" class="interlanguage-link-target"><span>മലയാളം</span></a></li><li class="interlanguage-link interwiki-mn mw-list-item"><a href="https://mn.wikipedia.org/wiki/%D0%90%D1%82%D0%BE%D0%BC%D1%8B%D0%BD_%D0%B6%D0%B8%D0%BD%D0%B3%D0%B8%D0%B9%D0%BD_%D0%BD%D1%8D%D0%B3%D0%B6" title="Атомын жингийн нэгж - mongolo" lang="mn" hreflang="mn" data-title="Атомын жингийн нэгж" data-language-autonym="Монгол" data-language-local-name="mongolo" class="interlanguage-link-target"><span>Монгол</span></a></li><li class="interlanguage-link interwiki-nap mw-list-item"><a href="https://nap.wikipedia.org/wiki/Unit%C3%A0_e%27_massa_atomeca" title="Unità e' massa atomeca - napoletano" lang="nap" hreflang="nap" data-title="Unità e' massa atomeca" data-language-autonym="Napulitano" data-language-local-name="napoletano" class="interlanguage-link-target"><span>Napulitano</span></a></li><li class="interlanguage-link interwiki-nds mw-list-item"><a href="https://nds.wikipedia.org/wiki/Atomare_Masseneenheit" title="Atomare Masseneenheit - basso tedesco" lang="nds" hreflang="nds" data-title="Atomare Masseneenheit" data-language-autonym="Plattdüütsch" data-language-local-name="basso tedesco" class="interlanguage-link-target"><span>Plattdüütsch</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Atomaire_massa-eenheid" title="Atomaire massa-eenheid - olandese" lang="nl" hreflang="nl" data-title="Atomaire massa-eenheid" data-language-autonym="Nederlands" data-language-local-name="olandese" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-nn mw-list-item"><a href="https://nn.wikipedia.org/wiki/Atommasseeining" title="Atommasseeining - norvegese nynorsk" lang="nn" hreflang="nn" data-title="Atommasseeining" data-language-autonym="Norsk nynorsk" data-language-local-name="norvegese nynorsk" class="interlanguage-link-target"><span>Norsk nynorsk</span></a></li><li class="interlanguage-link interwiki-no mw-list-item"><a href="https://no.wikipedia.org/wiki/Atommasseenhet" title="Atommasseenhet - norvegese bokmål" lang="nb" hreflang="nb" data-title="Atommasseenhet" data-language-autonym="Norsk bokmål" data-language-local-name="norvegese bokmål" class="interlanguage-link-target"><span>Norsk bokmål</span></a></li><li class="interlanguage-link interwiki-oc mw-list-item"><a href="https://oc.wikipedia.org/wiki/Unitat_de_massa_atomica" title="Unitat de massa atomica - occitano" lang="oc" hreflang="oc" data-title="Unitat de massa atomica" data-language-autonym="Occitan" data-language-local-name="occitano" class="interlanguage-link-target"><span>Occitan</span></a></li><li class="interlanguage-link interwiki-pa mw-list-item"><a href="https://pa.wikipedia.org/wiki/%E0%A8%85%E0%A8%9F%E0%A8%BE%E0%A8%AE%E0%A8%BF%E0%A8%95_%E0%A8%AE%E0%A8%BE%E0%A8%B8_%E0%A8%AF%E0%A9%82%E0%A8%A8%E0%A8%BF%E0%A8%9F" title="ਅਟਾਮਿਕ ਮਾਸ ਯੂਨਿਟ - punjabi" lang="pa" hreflang="pa" data-title="ਅਟਾਮਿਕ ਮਾਸ ਯੂਨਿਟ" data-language-autonym="ਪੰਜਾਬੀ" data-language-local-name="punjabi" class="interlanguage-link-target"><span>ਪੰਜਾਬੀ</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/Jednostka_masy_atomowej" title="Jednostka masy atomowej - polacco" lang="pl" hreflang="pl" data-title="Jednostka masy atomowej" data-language-autonym="Polski" data-language-local-name="polacco" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-pms mw-list-item"><a href="https://pms.wikipedia.org/wiki/Unit%C3%A0_%C3%ABd_massa_at%C3%B2mica" title="Unità ëd massa atòmica - piemontese" lang="pms" hreflang="pms" data-title="Unità ëd massa atòmica" data-language-autonym="Piemontèis" data-language-local-name="piemontese" class="interlanguage-link-target"><span>Piemontèis</span></a></li><li class="interlanguage-link interwiki-pnb mw-list-item"><a href="https://pnb.wikipedia.org/wiki/%D8%AC%D9%88%DB%81%D8%B1%DB%8C_%DA%A9%D9%85%DB%8C%D8%AA%DB%8C_%D8%A7%DA%A9%D8%A7%D8%A6%DB%8C" title="جوہری کمیتی اکائی - Western Punjabi" lang="pnb" hreflang="pnb" data-title="جوہری کمیتی اکائی" data-language-autonym="پنجابی" data-language-local-name="Western Punjabi" class="interlanguage-link-target"><span>پنجابی</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/Unidade_de_massa_at%C3%B4mica" title="Unidade de massa atômica - portoghese" lang="pt" hreflang="pt" data-title="Unidade de massa atômica" data-language-autonym="Português" data-language-local-name="portoghese" 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/Unitate_atomic%C4%83_de_mas%C4%83" title="Unitate atomică de masă - rumeno" lang="ro" hreflang="ro" data-title="Unitate atomică de masă" data-language-autonym="Română" data-language-local-name="rumeno" class="interlanguage-link-target"><span>Română</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/%D0%90%D1%82%D0%BE%D0%BC%D0%BD%D0%B0%D1%8F_%D0%B5%D0%B4%D0%B8%D0%BD%D0%B8%D1%86%D0%B0_%D0%BC%D0%B0%D1%81%D1%81%D1%8B" title="Атомная единица массы - russo" lang="ru" hreflang="ru" data-title="Атомная единица массы" data-language-autonym="Русский" data-language-local-name="russo" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-scn mw-list-item"><a href="https://scn.wikipedia.org/wiki/Unitati_di_massa_at%C3%B2mica" title="Unitati di massa atòmica - siciliano" lang="scn" hreflang="scn" data-title="Unitati di massa atòmica" data-language-autonym="Sicilianu" data-language-local-name="siciliano" class="interlanguage-link-target"><span>Sicilianu</span></a></li><li class="interlanguage-link interwiki-sh mw-list-item"><a href="https://sh.wikipedia.org/wiki/Jedinica_atomske_mase" title="Jedinica atomske mase - serbo-croato" lang="sh" hreflang="sh" data-title="Jedinica atomske mase" data-language-autonym="Srpskohrvatski / српскохрватски" data-language-local-name="serbo-croato" class="interlanguage-link-target"><span>Srpskohrvatski / српскохрватски</span></a></li><li class="interlanguage-link interwiki-simple mw-list-item"><a href="https://simple.wikipedia.org/wiki/Dalton_(unit)" title="Dalton (unit) - Simple English" lang="en-simple" hreflang="en-simple" data-title="Dalton (unit)" 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-sk mw-list-item"><a href="https://sk.wikipedia.org/wiki/At%C3%B3mov%C3%A1_hmotnostn%C3%A1_jednotka" title="Atómová hmotnostná jednotka - slovacco" lang="sk" hreflang="sk" data-title="Atómová hmotnostná jednotka" data-language-autonym="Slovenčina" data-language-local-name="slovacco" 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/Enota_atomske_mase" title="Enota atomske mase - sloveno" lang="sl" hreflang="sl" data-title="Enota atomske mase" data-language-autonym="Slovenščina" data-language-local-name="sloveno" class="interlanguage-link-target"><span>Slovenščina</span></a></li><li class="interlanguage-link interwiki-sr mw-list-item"><a href="https://sr.wikipedia.org/wiki/%D0%88%D0%B5%D0%B4%D0%B8%D0%BD%D0%B8%D1%86%D0%B0_%D0%B0%D1%82%D0%BE%D0%BC%D1%81%D0%BA%D0%B5_%D0%BC%D0%B0%D1%81%D0%B5" title="Јединица атомске масе - serbo" lang="sr" hreflang="sr" data-title="Јединица атомске масе" data-language-autonym="Српски / srpski" data-language-local-name="serbo" class="interlanguage-link-target"><span>Српски / srpski</span></a></li><li class="interlanguage-link interwiki-sv mw-list-item"><a href="https://sv.wikipedia.org/wiki/Atommassenhet" title="Atommassenhet - svedese" lang="sv" hreflang="sv" data-title="Atommassenhet" data-language-autonym="Svenska" data-language-local-name="svedese" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-ta mw-list-item"><a href="https://ta.wikipedia.org/wiki/%E0%AE%85%E0%AE%A3%E0%AF%81_%E0%AE%A8%E0%AE%BF%E0%AE%B1%E0%AF%88_%E0%AE%85%E0%AE%B2%E0%AE%95%E0%AF%81" title="அணு நிறை அலகு - tamil" lang="ta" hreflang="ta" data-title="அணு நிறை அலகு" data-language-autonym="தமிழ்" data-language-local-name="tamil" class="interlanguage-link-target"><span>தமிழ்</span></a></li><li class="interlanguage-link interwiki-tg mw-list-item"><a href="https://tg.wikipedia.org/wiki/%D0%92%D0%BE%D2%B3%D0%B8%D0%B4%D0%B8_%D0%B0%D1%82%D0%BE%D0%BC%D0%B8%D0%B8_%D0%BC%D0%B0%D1%81%D1%81%D0%B0" title="Воҳиди атомии масса - tagico" lang="tg" hreflang="tg" data-title="Воҳиди атомии масса" data-language-autonym="Тоҷикӣ" data-language-local-name="tagico" class="interlanguage-link-target"><span>Тоҷикӣ</span></a></li><li class="interlanguage-link interwiki-th mw-list-item"><a href="https://th.wikipedia.org/wiki/%E0%B8%AB%E0%B8%99%E0%B9%88%E0%B8%A7%E0%B8%A2%E0%B8%A1%E0%B8%A7%E0%B8%A5%E0%B8%AD%E0%B8%B0%E0%B8%95%E0%B8%AD%E0%B8%A1" title="หน่วยมวลอะตอม - thailandese" lang="th" hreflang="th" data-title="หน่วยมวลอะตอม" data-language-autonym="ไทย" data-language-local-name="thailandese" 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/Atomik_k%C3%BCtle_birimi" title="Atomik kütle birimi - turco" lang="tr" hreflang="tr" data-title="Atomik kütle birimi" data-language-autonym="Türkçe" data-language-local-name="turco" 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%90%D1%82%D0%BE%D0%BC%D0%BD%D0%B0_%D0%BE%D0%B4%D0%B8%D0%BD%D0%B8%D1%86%D1%8F_%D0%BC%D0%B0%D1%81%D0%B8" title="Атомна одиниця маси - ucraino" lang="uk" hreflang="uk" data-title="Атомна одиниця маси" data-language-autonym="Українська" data-language-local-name="ucraino" 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/%D8%AC%D9%88%DB%81%D8%B1%DB%8C_%DA%A9%D9%85%DB%8C%D8%AA%DB%8C_%D8%A7%DA%A9%D8%A7%D8%A6%DB%8C" title="جوہری کمیتی اکائی - urdu" lang="ur" hreflang="ur" data-title="جوہری کمیتی اکائی" data-language-autonym="اردو" data-language-local-name="urdu" class="interlanguage-link-target"><span>اردو</span></a></li><li class="interlanguage-link interwiki-uz mw-list-item"><a href="https://uz.wikipedia.org/wiki/Massaning_atom_birligi" title="Massaning atom birligi - uzbeco" lang="uz" hreflang="uz" data-title="Massaning atom birligi" data-language-autonym="Oʻzbekcha / ўзбекча" data-language-local-name="uzbeco" class="interlanguage-link-target"><span>Oʻzbekcha / ўзбекча</span></a></li><li class="interlanguage-link interwiki-vi mw-list-item"><a href="https://vi.wikipedia.org/wiki/Dalton_(%C4%91%C6%A1n_v%E1%BB%8B)" title="Dalton (đơn vị) - vietnamita" lang="vi" hreflang="vi" data-title="Dalton (đơn vị)" data-language-autonym="Tiếng Việt" data-language-local-name="vietnamita" class="interlanguage-link-target"><span>Tiếng Việt</span></a></li><li class="interlanguage-link interwiki-war mw-list-item"><a href="https://war.wikipedia.org/wiki/Yunit_masa_atomiko" title="Yunit masa atomiko - waray" lang="war" hreflang="war" data-title="Yunit masa atomiko" data-language-autonym="Winaray" data-language-local-name="waray" 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style="background:#A2A2A2;color:#fff">Unità di massa relativa</th></tr><tr class="sinottico_divisione"><th colspan="2" style="background:#D2D2D2">Informazioni generali</th></tr><tr><th><a href="/wiki/Grandezza_fisica" title="Grandezza fisica">Grandezza</a></th><td><a href="/wiki/Massa_(fisica)" title="Massa (fisica)">massa</a> </td></tr><tr><th>Simbolo</th><td>amu, Da, u, a.m.u., uma, u.m.a. </td></tr><tr><th><a href="/wiki/Eponimo" title="Eponimo">Eponimo</a></th><td><a href="/wiki/John_Dalton" title="John Dalton">John Dalton</a> </td></tr><tr class="sinottico_divisione"><th colspan="2" style="background:#D2D2D2"><a href="/wiki/Conversione_delle_unit%C3%A0_di_misura" title="Conversione delle unità di misura">Conversioni</a> <table width="100%" style="font-weight:normal;font-style:italic; text-align:left"> <tbody><tr> <td width="50%">1 amu in...</td> <td>...equivale a... </td></tr></tbody></table></th></tr><tr><th><a href="/wiki/Sistema_internazionale_di_unit%C3%A0_di_misura" title="Sistema internazionale di unità di misura">Unità SI</a></th><td>≈<span class="nowrap"><span data-sort-value="6973166054000000000♠"></span>1,66054<span style="margin-left:0.25em;margin-right:0.15em;">×</span>10<sup>−27</sup></span> <a href="/wiki/Chilogrammo" title="Chilogrammo">kg</a> </td></tr><tr><th><a href="/wiki/Sistema_CGS" title="Sistema CGS">Unità CGS</a></th><td>≈<span class="nowrap"><span data-sort-value="6976166054000000000♠"></span>1,66054<span style="margin-left:0.25em;margin-right:0.15em;">×</span>10<sup>−24</sup></span> <a href="/wiki/Grammo" title="Grammo">g</a> </td></tr><tr><th><a href="/wiki/Sistema_MTS" title="Sistema MTS">Unità MTS</a></th><td>≈<span class="nowrap"><span data-sort-value="6970166054000000000♠"></span>1,66054<span style="margin-left:0.25em;margin-right:0.15em;">×</span>10<sup>−30</sup></span> <a href="/wiki/Tonnellata" title="Tonnellata">t</a> </td></tr><tr><th><a href="/wiki/Sistema_consuetudinario_statunitense" title="Sistema consuetudinario statunitense">Unità US</a>/<a href="/wiki/Sistema_imperiale_britannico" title="Sistema imperiale britannico">Imp</a></th><td>≈<span class="nowrap"><span data-sort-value="6973366086000000000♠"></span>3,66086<span style="margin-left:0.25em;margin-right:0.15em;">×</span>10<sup>−27</sup></span> <a href="/wiki/Libbra" title="Libbra">lb</a><br />≈<span class="nowrap"><span data-sort-value="6974585738000000000♠"></span>5,85738<span style="margin-left:0.25em;margin-right:0.15em;">×</span>10<sup>−26</sup></span> <a href="/wiki/Oncia_(unit%C3%A0_di_misura)" title="Oncia (unità di misura)">oz</a> </td></tr><tr><th><a href="/wiki/Sistema_pratico_degli_ingegneri" title="Sistema pratico degli ingegneri">Unità ST</a></th><td>≈<span class="nowrap"><span data-sort-value="6972169328000000000♠"></span>1,69328<span style="margin-left:0.25em;margin-right:0.15em;">×</span>10<sup>−28</sup></span> <a href="/wiki/Unit%C3%A0_tecnica_di_massa" title="Unità tecnica di massa">UTM</a> </td></tr><tr><th><a href="/wiki/Sistema_troy" title="Sistema troy">Unità troy</a></th><td>≈<span class="nowrap"><span data-sort-value="6974533876000000000♠"></span>5,33876<span style="margin-left:0.25em;margin-right:0.15em;">×</span>10<sup>−26</sup></span> <a href="/wiki/Oncia_troy" title="Oncia troy">oz t</a> </td></tr><tr><th><a href="/wiki/Unit%C3%A0_di_misura_di_Planck" title="Unità di misura di Planck">Unità di Planck</a></th><td>≈<span class="nowrap"><span data-sort-value="6980762958000000000♠"></span>7,62958<span style="margin-left:0.25em;margin-right:0.15em;">×</span>10<sup>−20</sup></span> <a href="/wiki/Massa_di_Planck" title="Massa di Planck">m<sub>P</sub></a> </td></tr><tr><th><a href="/wiki/Unit%C3%A0_atomiche" title="Unità atomiche">Unità atomiche</a></th><td>≈<span class="nowrap"><span data-sort-value="7003182288000000000♠"></span>1<span style="margin-left:.25em;">822</span>,88</span> <a href="/wiki/Massa_a_riposo_dell%27elettrone" title="Massa a riposo dell'elettrone">m<sub>e</sub></a> </td></tr><tr><td class="sinottico_piede2 noprint nomobile metadata" colspan="2"><a href="https://www.wikidata.org/wiki/Q483261" class="extiw" title="d:Q483261"><span title="Modifica i dati della voce Unità di massa atomica su Wikidata">Modifica dati su Wikidata</span></a><b> ·</b> <a href="/wiki/Template:Unit%C3%A0/man" title="Template:Unità/man"><span title="Manuale del template Unità">Manuale</span></a></td></tr></tbody></table> <p>L'<b>unità di massa atomica unificata</b> (<b>amu</b>, dall'inglese <i>atomic mass unit</i>), detta anche <b>dalton</b> (<b>Da</b>), è un'<a href="/wiki/Unit%C3%A0_di_misura" title="Unità di misura">unità di misura</a> tecnica per la <a href="/wiki/Massa_atomica" title="Massa atomica">massa atomica</a>. </p><p>Non fa parte del sistema <a href="/wiki/Sistema_internazionale_di_unit%C3%A0_di_misura" title="Sistema internazionale di unità di misura">SI</a>,<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> ma viene ancora riconosciuta come unità derivata in quanto in passato utilizzata in <a href="/wiki/Chimica" title="Chimica">chimica</a> e <a href="/wiki/Biochimica" title="Biochimica">biochimica</a>. <style data-mw-deduplicate="TemplateStyles:r140554517">.mw-parser-output .chiarimento{background:#ffeaea;color:#444444}.mw-parser-output .chiarimento-apice{color:#EE0700}@media screen{html.skin-theme-clientpref-night .mw-parser-output .chiarimento{background:rgba(179,36,36,0.21);color:inherit}html.skin-theme-clientpref-night .mw-parser-output .chiarimento-apice{color:#b32424}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .chiarimento{background:rgba(179,36,36,0.21);color:inherit}html.skin-theme-clientpref-os .mw-parser-output .chiarimento-apice{color:#b32424}}</style><span class="chiarimento" title="Queste informazioni non sono comprovate da fonti attendibili.">Attualmente si preferisce utilizzare sottomultipli del <a href="/wiki/Chilogrammo" title="Chilogrammo">chilogrammo</a> o multipli dell'<a href="/wiki/Elettronvolt" title="Elettronvolt">elettronvolt</a>, in particolare il gigaelettronvolt (<a href="/wiki/Elettronvolt" title="Elettronvolt">GeV</a>)</span><sup class="noprint chiarimento-apice" title="Queste informazioni non sono comprovate da fonti attendibili.">[<i><a href="/wiki/Wikipedia:Uso_delle_fonti" title="Wikipedia:Uso delle fonti">senza fonte</a></i>]</sup>: </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 1\ u=0{,}9315\ GeV/c^{2}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mn>1</mn> <mtext> </mtext> <mi>u</mi> <mo>=</mo> <mn>0,931</mn> <mn>5</mn> <mtext> </mtext> <mi>G</mi> <mi>e</mi> <mi>V</mi> <mrow class="MJX-TeXAtom-ORD"> <mo>/</mo> </mrow> <msup> <mi>c</mi> <mrow class="MJX-TeXAtom-ORD"> <mn>2</mn> </mrow> </msup> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle 1\ u=0{,}9315\ GeV/c^{2}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/b598e349a62bdd03b85d0e5db084587dae09e86e" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:21.132ex; height:3.176ex;" alt="{\displaystyle 1\ u=0{,}9315\ GeV/c^{2}}"></span> </p><p>Altri suoi simboli sono <b>u</b> (simbolo più ambiguo), o <b>uma</b>, che è l'acronimo in lingua italiana. </p><p>Veniva utilizzata per indicare la <a href="/wiki/Massa_(fisica)" title="Massa (fisica)">massa</a> delle particelle elementari, di singoli <a href="/wiki/Atomo" title="Atomo">atomi</a> (<a href="/wiki/Massa_atomica" title="Massa atomica">massa atomica</a>), <a href="/wiki/Molecola" title="Molecola">molecole</a> (<a href="/wiki/Massa_molecolare" title="Massa molecolare">massa molecolare</a>), <a href="/wiki/Ione" title="Ione">ioni</a>, <a href="/wiki/Radicale_libero" title="Radicale libero">radicali</a>. Questa unità era diffusa in passato, perché sperimentalmente risultava più immediato confrontare masse di atomi e molecole, piuttosto che misurarne effettivamente la loro massa, specialmente quando si utilizzava uno <a href="/wiki/Spettrometro_di_massa" title="Spettrometro di massa">spettrometro di massa</a>. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Definizione">Definizione</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Unit%C3%A0_di_massa_atomica&veaction=edit&section=1" title="Modifica la sezione Definizione" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Unit%C3%A0_di_massa_atomica&action=edit&section=1" title="Edit section's source code: Definizione"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>La definizione era inizialmente la massa di un atomo di <a href="/wiki/Idrogeno" title="Idrogeno">idrogeno</a>. In seguito si passò per migliorare la precisione di misura, a "la dodicesima parte della massa di un atomo di <a href="/wiki/Isotopi_del_carbonio" title="Isotopi del carbonio">carbonio-12</a>" (<sup>12</sup>C). Quindi un numero di queste unità pari al valore numerico della <a href="/wiki/Costante_di_Avogadro" title="Costante di Avogadro">costante di Avogadro</a> corrisponde a un grammo: </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 1\ g=6{,}022\times 10^{23}\ u}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mn>1</mn> <mtext> </mtext> <mi>g</mi> <mo>=</mo> <mn>6,022</mn> <mo>×<!-- × --></mo> <msup> <mn>10</mn> <mrow class="MJX-TeXAtom-ORD"> <mn>23</mn> </mrow> </msup> <mtext> </mtext> <mi>u</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle 1\ g=6{,}022\times 10^{23}\ u}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/e1974d07b0e4e2b7fc75a1ef446d9e5ec8f1da09" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:20.206ex; height:3.009ex;" alt="{\displaystyle 1\ g=6{,}022\times 10^{23}\ u}"></span> </p><p>invertendo questa conversione si trova che<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>: </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="{\textstyle 1\ u\simeq 1{,}661\times 10^{-27}\ kg}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="false" scriptlevel="0"> <mn>1</mn> <mtext> </mtext> <mi>u</mi> <mo>≃<!-- ≃ --></mo> <mn>1,661</mn> <mo>×<!-- × --></mo> <msup> <mn>10</mn> <mrow class="MJX-TeXAtom-ORD"> <mo>−<!-- − --></mo> <mn>27</mn> </mrow> </msup> <mtext> </mtext> <mi>k</mi> <mi>g</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\textstyle 1\ u\simeq 1{,}661\times 10^{-27}\ kg}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/8a5f06656832e5f72fec644ce2f3761560cd0530" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:22.696ex; height:3.009ex;" alt="{\textstyle 1\ u\simeq 1{,}661\times 10^{-27}\ kg}"></span> </p><p>ovvero </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 1\ u\simeq 1{,}661\times 10^{-24}\ g}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mn>1</mn> <mtext> </mtext> <mi>u</mi> <mo>≃<!-- ≃ --></mo> <mn>1,661</mn> <mo>×<!-- × --></mo> <msup> <mn>10</mn> <mrow class="MJX-TeXAtom-ORD"> <mo>−<!-- − --></mo> <mn>24</mn> </mrow> </msup> <mtext> </mtext> <mi>g</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle 1\ u\simeq 1{,}661\times 10^{-24}\ g}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/936db0d4515b028eeb2bd22a5aa7f086f9e75937" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:21.485ex; height:3.009ex;" alt="{\displaystyle 1\ u\simeq 1{,}661\times 10^{-24}\ g}"></span> </p><p>L'unità di massa atomica era conveniente nella pratica sperimentale perché un <a href="/wiki/Nucleone" title="Nucleone">nucleone</a> legato ha una massa circa pari a 1 unità, quindi un atomo o una molecola, con un <a href="/wiki/Numero_di_massa" title="Numero di massa">numero di massa</a> <i>A</i> ha una massa circa di <i>A</i> unità di massa atomiche. La ragione consiste nel fatto che un atomo di carbonio-12, da cui l'unità di massa atomica trae la sua definizione, contiene 6 protoni, 6 neutroni e 6 elettroni, con protoni e neutroni aventi all'incirca la stessa massa e gli elettroni aventi massa trascurabile. Questa approssimazione è comunque grossolana poiché non tiene conto della variazione della massa con l'<a href="/wiki/Energia_di_legame" title="Energia di legame">energia di legame</a> dei <a href="/wiki/Nucleo_atomico" title="Nucleo atomico">nuclei atomici</a> (in base alla nota equazione di <a href="/wiki/Albert_Einstein" title="Albert Einstein">Einstein</a>: <a href="/wiki/E%3Dmc%C2%B2" title="E=mc²"><i>E</i> = <i>mc</i>²</a>) e della differenza di massa tra il protone e il neutrone. </p> <div class="mw-heading mw-heading2"><h2 id="Simboli">Simboli</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Unit%C3%A0_di_massa_atomica&veaction=edit&section=2" title="Modifica la sezione Simboli" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Unit%C3%A0_di_massa_atomica&action=edit&section=2" title="Edit section's source code: Simboli"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>L'Unione internazionale di chimica pura e applicata (<a href="/wiki/Unione_internazionale_di_chimica_pura_e_applicata" title="Unione internazionale di chimica pura e applicata">IUPAC</a>), raccomanda di utilizzare il simbolo u per indicare l'unità di massa atomica unificata. Tuttavia, sia in biochimica sia in biologia molecolare è consuetudine utilizzare Da.<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>Specialmente in vecchie pubblicazioni è possibile trovare l'acronimo uma oppure amu, oppure l'unità di misura non è indicata affatto. Quest'ultimo metodo era giustificato in passato con l'introduzione della massa atomica relativa che, essendo un rapporto tra la massa assoluta dell'atomo o del composto sotto esame e l'unità di massa atomica, doveva essere una <a href="/wiki/Numero_adimensionale" title="Numero adimensionale">quantità adimensionale</a>. </p> <div class="mw-heading mw-heading2"><h2 id="Fattori_di_conversione">Fattori di conversione</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Unit%C3%A0_di_massa_atomica&veaction=edit&section=3" title="Modifica la sezione Fattori di conversione" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Unit%C3%A0_di_massa_atomica&action=edit&section=3" title="Edit section's source code: Fattori di conversione"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <dl><dd><ul><li>1 u = 1/<i>N</i><sub>A</sub> <a href="/wiki/Grammo" title="Grammo">g</a>= 1/(1000 <i>N</i><sub>A</sub>) <a href="/wiki/Chilogrammo" title="Chilogrammo">kg</a></li> <li>1 u ≈ <span class="nowrap"><span data-sort-value="6973166053892099999♠"></span>1,660538921<span style="margin-left:0.25em;margin-right:0.15em;">×</span>10<sup>−27</sup> <a href="/wiki/Chilogrammo" title="Chilogrammo">kg</a></span></li> <li>1 u ≈ <span class="nowrap"><span data-sort-value="7002931493614800000♠"></span>931,4936148 <a href="/wiki/Elettronvolt" title="Elettronvolt">MeV/<i>c</i><sup>2</sup></a></span>, confrontabile con altre (vicine) unità di massa quali <ul><li>protone: 938,27 Mev/c<sup>2</sup></li> <li>nucleo d'Idrogeno: 938,8 Mev/c<sup>2</sup></li></ul></li></ul></dd></dl> <p>La <a href="/wiki/Mole" title="Mole">mole</a> è definibile come il numero di molecole che mediamente pesano <i>x</i> unità contenute in <i>x</i> grammi di quella sostanza. Quindi l'unità di massa atomica coincide esattamente con l'unità di misura grammo/mole: </p> <dl><dd>1 u = 1 g/mol</dd></dl> <p>Per esempio, la massa molecolare dell'acqua è 18,01508 u ovvero 18,01508 g/mol; allo stesso modo, 1 g di acqua contiene 1 g × <i>N</i><sub><i>A</i></sub>/18,01508 g/mol ≈ <span class="nowrap"><span data-sort-value="7022334280000000000♠"></span>3,3428<span style="margin-left:0.25em;margin-right:0.15em;">×</span>10<sup>22</sup></span> molecole. </p> <div class="mw-heading mw-heading2"><h2 id="Storia">Storia</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Unit%C3%A0_di_massa_atomica&veaction=edit&section=4" title="Modifica la sezione Storia" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Unit%C3%A0_di_massa_atomica&action=edit&section=4" title="Edit section's source code: Storia"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Il chimico <a href="/wiki/John_Dalton" title="John Dalton">John Dalton</a> fu il primo a suggerire di utilizzare la massa di un atomo di idrogeno come riferimento nel confronto delle masse di atomi e composti chimici. </p><p>La scelta cadde inizialmente sull'atomo di idrogeno poiché questo era il più leggero tra tutti gli atomi, ma si rivelò in seguito inadeguata perché questo elemento non consente confronti diretti. <a href="/wiki/Francis_William_Aston" title="Francis William Aston">Francis William Aston</a>, l'inventore dello spettrometro di massa, propose in seguito di utilizzare come campione 1/16 della massa di un atomo di <a href="/wiki/Ossigeno" title="Ossigeno">ossigeno</a>-16. </p><p>Prima del <a href="/wiki/1961" title="1961">1961</a>, l'unità di massa atomica usata in ambito fisico fu definita come 1/16 della massa di un atomo di ossigeno-16, ma l'unità di massa atomica usata in ambito chimico fu definita come 1/16 della <i>massa media</i> di un atomo di ossigeno (tenendo quindi conto dell'abbondanza dei diversi isotopi di ossigeno presenti in natura). Questa ambiguità fu chiarita nel <a href="/wiki/1960" title="1960">1960</a> dall'Unione internazionale di chimica pura e applicata (IUPAC) introducendo l'attuale definizione di unità di massa atomica <i>unificata</i>. </p> <div class="mw-heading mw-heading2"><h2 id="Relazione_con_il_sistema_internazionale">Relazione con il sistema internazionale</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Unit%C3%A0_di_massa_atomica&veaction=edit&section=5" title="Modifica la sezione Relazione con il sistema internazionale" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Unit%C3%A0_di_massa_atomica&action=edit&section=5" title="Edit section's source code: Relazione con il sistema internazionale"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>La precedente definizione della <a href="/wiki/Mole" title="Mole">mole</a>, unità fondamentale del SI, accettata dalla <a href="/wiki/Conf%C3%A9rence_g%C3%A9n%C3%A9rale_des_poids_et_mesures" title="Conférence générale des poids et mesures">CGPM</a> nel 1971 è: </p> <ol><li>La mole (simbolo mol) è la quantità di sostanza di un sistema che contiene tante entità elementari quanti sono gli atomi in 0,012 chilogrammi di carbonio-12.</li> <li>Quando si usa la mole, le entità elementari devono essere specificate e possono essere atomi, molecole, ioni, elettroni e altre particelle o gruppi specifici di tali particelle.</li></ol> <p>Tuttavia, la prima parte di questa definizione è cambiata il 20 maggio 2019: </p> <dl><dd>La mole, simbolo mol, è l'unità del SI della quantità di sostanza. Una mole contiene esattamente <span class="nowrap"><span data-sort-value="7023602214076000000♠"></span>6,02214076<span style="margin-left:0.25em;margin-right:0.15em;">×</span>10<sup>23</sup></span> entità elementari. Questo numero è pari al numero di Avogadro, <i>N</i><sub>A</sub>, espresso nell'unità mol<sup>−1</sup>.<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><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></dd></dl> <p>Una conseguenza di questo cambio è che la relazione attualmente definita tra la massa dell'atomo <sup>12</sup>C, il dalton, il chilogrammo e il numero di Avogadro non sarà più valida. Deve cambiare una delle seguenti; </p> <ul><li>La massa dell'atomo <sup>12</sup>C è esattamente 12 dalton.</li> <li>Il numero di dalton in un grammo è esattamente il valore del numero di Avogadro (ovvero, <span class="nowrap">1 g/Da = 1 mol ⋅ <i>N</i><sub>A</sub></span>).</li></ul> <p>La formulazione della nona Brochure del SI<sup id="cite_ref-9thSIbrochure_6-0" class="reference"><a href="#cite_note-9thSIbrochure-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-SInote_7-0" class="reference"><a href="#cite_note-SInote-7"><span class="cite-bracket">[</span>N 1<span class="cite-bracket">]</span></a></sup> implica che la prima affermazione rimane valida, il che significa che la seconda non è più vera. La costante di massa molare non è più esattamente uguale a 1 g/mol, sebbene questo valore sia ancora un'ottima approssimazione. Dato che l'unità di massa atomica unificata è un dodicesimo della massa di un atomo del carbonio-12, ovvero la massa di tale atomo è 12 u, segue che ci sono circa <i>N</i><sub>A</sub> atomi di carbonio-12 in 0.012 kg di carbonio-12. Ciò si può esprimere matematicamente: </p> <dl><dd>12 Da × <i>N</i><sub>A</sub> ≈ 0.012 kg/mol, oppure</dd> <dd>1 Da × <i>N</i><sub>A</sub> ≈ 0.001 kg/mol.</dd></dl> <div class="mw-heading mw-heading2"><h2 id="Note">Note</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Unit%C3%A0_di_massa_atomica&veaction=edit&section=6" title="Modifica la sezione Note" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Unit%C3%A0_di_massa_atomica&action=edit&section=6" title="Edit section's source code: Note"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <dl><dt>Annotazioni</dt></dl> <div class="mw-references-wrap"><ol class="references"> <li id="cite_note-SInote-7"><a href="#cite_ref-SInote_7-0"><b>^</b></a> <span class="reference-text">In una nota a pié di pagina nella Table 8 riguardante le unità non-SI, si afferma: <style data-mw-deduplicate="TemplateStyles:r139517313">.mw-parser-output .itwiki-template-citazione{margin-bottom:.5em;font-size:95%;padding-left:2.4em;padding-right:1.2em}.mw-parser-output .itwiki-template-citazione-doppia{display:flex;gap:1.2em}.mw-parser-output .itwiki-template-citazione-doppia>div{width:0;flex:1 1 0}.mw-parser-output .itwiki-template-citazione-footer{padding:0 1.2em 0 0;margin:0}</style><div class="itwiki-template-citazione"> <div class="itwiki-template-citazione-doppia"> <div>(<span style="font-weight:bolder; font-size:80%"><abbr title="inglese">EN</abbr></span>) <p>«The dalton (Da) and the unified atomic mass unit (u) are alternative names (and symbols) for the same unit, equal to 1/12 of the mass of a free carbon 12 atom, at rest and in its ground state.» </p> </div> <div>(<span style="font-weight:bolder; font-size:80%"><abbr title="italiano">IT</abbr></span>) <p>«Il dalton (Da) e l'unità di massa atomica unificata (u) sono nomi (e simboli) alternativi per la stessa unità, pari a 1/12 della massa di un atomo libero di carbonio-12, in quiete e nello stato fondamentale.» </p> </div></div></div><br /></span> </li> </ol></div> <dl><dt>Fonti</dt></dl> <div class="mw-references-wrap"><ol class="references"> <li id="cite_note-1"><a href="#cite_ref-1"><b>^</b></a> <span class="reference-text"><cite class="citation web" style="font-style:normal"> The International Union of Pure and Applied Chemistry (IUPAC), <a rel="nofollow" class="external text" href="https://goldbook.iupac.org/terms/view/U06554"><span style="font-style:italic;">IUPAC - unified atomic mass unit (U06554)</span></a>, su <span style="font-style:italic;">goldbook.iupac.org</span>. <small>URL consultato il 4 novembre 2023</small>.</cite></span> </li> <li id="cite_note-2"><a href="#cite_ref-2"><b>^</b></a> <span class="reference-text"><cite class="citation web" style="font-style:normal"> <a rel="nofollow" class="external text" href="http://physics.nist.gov/constants"><span style="font-style:italic;">Fundamental Physical Constants</span></a>, in <span style="font-style:italic;">The NIST Reference on Constants, Units, and Uncertainty</span>, <a href="/wiki/National_Institute_of_Standards_and_Technology" title="National Institute of Standards and Technology">NIST</a>, 2010.</cite></span> </li> <li id="cite_note-3"><a href="#cite_ref-3"><b>^</b></a> <span class="reference-text"><cite class="citation web" style="font-style:normal">(<span style="font-weight:bolder; font-size:80%"><abbr title="inglese">EN</abbr></span>) <a rel="nofollow" class="external text" href="http://www.iupac.org/publications/books/gbook/green_book_2ed.pdf"><span style="font-style:italic;">Quantities, Units and Symbols in Physical Chemistry</span></a> (<span style="font-weight: bolder; font-size:80%"><abbr title="documento in formato PDF">PDF</abbr></span>), su <span style="font-style:italic;">iupac.org</span>.</cite></span> </li> <li id="cite_note-4"><a href="#cite_ref-4"><b>^</b></a> <span class="reference-text"><cite class="citation web" style="font-style:normal"> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20180127202612/https://www.bipm.org/utils/en/pdf/CIPM/CIPM2017-EN.pdf?page=23"><span style="font-style:italic;">CIPM Report of 106th Meeting</span></a>, su <span style="font-style:italic;">bipm.org</span>. <small>URL consultato il 4 luglio 2019</small> <small>(archiviato dall'<abbr title="https://www.bipm.org/utils/en/pdf/CIPM/CIPM2017-EN.pdf?page=23">url originale</abbr> il 27 gennaio 2018)</small>.</cite></span> </li> <li id="cite_note-5"><a href="#cite_ref-5"><b>^</b></a> <span class="reference-text"> <cite class="citation web" style="font-style:normal"> <a rel="nofollow" class="external text" href="https://www.nist.gov/si-redefinition/redefining-mole"><span style="font-style:italic;">Redefining the Mole</span></a>, su <span style="font-style:italic;">nist.gov</span>, NIST, 23 ottobre 2018. <small>URL consultato il 24 ottobre 2018</small>.</cite></span> </li> <li id="cite_note-9thSIbrochure-6"><a href="#cite_ref-9thSIbrochure_6-0"><b>^</b></a> <span class="reference-text"> <cite class="citation web" style="font-style:normal"> <a rel="nofollow" class="external text" href="https://www.bipm.org/en/publications/si-brochure/"><span style="font-style:italic;">9th edition of the SI Brochure</span></a>, su <span style="font-style:italic;">bipm.org</span>, BIPM, 2019. <small>URL consultato il 20 maggio 2019</small>.</cite></span> </li> </ol></div> <div class="mw-heading mw-heading2"><h2 id="Bibliografia">Bibliografia</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Unit%C3%A0_di_massa_atomica&veaction=edit&section=7" title="Modifica la sezione Bibliografia" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Unit%C3%A0_di_massa_atomica&action=edit&section=7" title="Edit section's source code: Bibliografia"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><cite class="citation libro" style="font-style:normal">(<span style="font-weight:bolder; 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VV., <span style="font-style:italic;">Quantities, Units and Symbols in Physical Chemistry - the IUPAC Green Book</span>, 3ª ed., Cambridge, RSC Publishing, 2007, <a href="/wiki/ISBN" title="ISBN">ISBN</a> <a href="/wiki/Speciale:RicercaISBN/0-85404-433-7" title="Speciale:RicercaISBN/0-85404-433-7">0-85404-433-7</a>.</cite></li></ul> <div class="mw-heading mw-heading2"><h2 id="Voci_correlate">Voci correlate</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Unit%C3%A0_di_massa_atomica&veaction=edit&section=8" title="Modifica la sezione Voci correlate" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Unit%C3%A0_di_massa_atomica&action=edit&section=8" title="Edit section's source code: Voci correlate"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Elettronvolt" title="Elettronvolt">ElettronVolt</a></li> <li><a href="/wiki/Numero_di_massa" title="Numero di massa">Numero di massa</a></li> <li><a href="/wiki/Metrologia" title="Metrologia">Metrologia</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="Collegamenti_esterni">Collegamenti esterni</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Unit%C3%A0_di_massa_atomica&veaction=edit&section=9" title="Modifica la sezione Collegamenti esterni" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Unit%C3%A0_di_massa_atomica&action=edit&section=9" title="Edit section's source code: Collegamenti esterni"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><cite class="citation web" style="font-style:normal">(<span style="font-weight:bolder; font-size:80%"><abbr title="inglese">EN</abbr></span>) <a rel="nofollow" class="external text" href="http://www.iupac.org/"><span style="font-style:italic;">International Union of Pure and Applied Chemistry</span></a>, su <span style="font-style:italic;">iupac.org</span>.</cite></li></ul> <style data-mw-deduplicate="TemplateStyles:r141815314">.mw-parser-output .navbox{border:1px solid #aaa;clear:both;margin:auto;padding:2px;width:100%}.mw-parser-output .navbox th{padding-left:1em;padding-right:1em;text-align:center}.mw-parser-output .navbox>tbody>tr:first-child>th{background:#ccf;font-size:90%;width:100%;color:var(--color-base,black)}.mw-parser-output .navbox_navbar{float:left;margin:0;padding:0 10px 0 0;text-align:left;width:6em}.mw-parser-output .navbox_title{font-size:110%}.mw-parser-output .navbox_abovebelow{background:#ddf;font-size:90%;font-weight:normal}.mw-parser-output .navbox_group{background:#ddf;font-size:90%;padding:0 10px;white-space:nowrap}.mw-parser-output .navbox_list{font-size:90%;width:100%}.mw-parser-output .navbox_list a{white-space:nowrap}html:not(.vector-feature-night-mode-enabled) .mw-parser-output .navbox_odd{background:#fdfdfd;color:var(--color-base,black)}html:not(.vector-feature-night-mode-enabled) .mw-parser-output .navbox_even{background:#f7f7f7;color:var(--color-base,black)}.mw-parser-output .navbox a.mw-selflink{color:var(--color-base,black)}.mw-parser-output .navbox_center{text-align:center}.mw-parser-output .navbox .navbox_image{padding-left:7px;vertical-align:middle;width:0}.mw-parser-output .navbox+.navbox{margin-top:-1px}.mw-parser-output .navbox .mw-collapsible-toggle{font-weight:normal;text-align:right;width:7em}body.skin--responsive .mw-parser-output .navbox_image img{max-width:none!important}.mw-parser-output .subnavbox{margin:-3px;width:100%}.mw-parser-output .subnavbox_group{background:#e6e6ff;padding:0 10px}@media screen{html.skin-theme-clientpref-night .mw-parser-output .navbox>tbody>tr:first-child>th{background:var(--background-color-interactive)!important}html.skin-theme-clientpref-night .mw-parser-output .navbox th{color:var(--color-base)!important}html.skin-theme-clientpref-night .mw-parser-output .navbox_abovebelow,html.skin-theme-clientpref-night .mw-parser-output .navbox_group{background:var(--background-color-interactive-subtle)!important}html.skin-theme-clientpref-night .mw-parser-output .subnavbox_group{background:var(--background-color-neutral-subtle)!important}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .navbox>tbody>tr:first-child>th{background:var(--background-color-interactive)!important}html.skin-theme-clientpref-os .mw-parser-output .navbox th{color:var(--color-base)!important}html.skin-theme-clientpref-os .mw-parser-output .navbox_abovebelow,html.skin-theme-clientpref-os .mw-parser-output .navbox_group{background:var(--background-color-interactive-subtle)!important}html.skin-theme-clientpref-os .mw-parser-output .subnavbox_group{background:var(--background-color-neutral-subtle)!important}}</style><table class="navbox mw-collapsible mw-collapsed noprint metadata" id="navbox-Unità_di_misura"><tbody><tr><th colspan="2"><div class="navbox_navbar"><div class="noprint plainlinks" style="background-color:transparent; 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width:22%;"><a href="/wiki/Sistema_pratico_degli_ingegneri" title="Sistema pratico degli ingegneri">Sistema Tecnico - MFS</a></th><td colspan="1" class="navbox_list navbox_odd"><table class="subnavbox"><tbody><tr><th class="subnavbox_group" style="text-align:center; width:22%;">Unità di base</th><td colspan="1"><a href="/wiki/Metro" title="Metro">metro</a><b> ·</b> <a href="/wiki/Chilogrammo_forza" title="Chilogrammo forza">chilogrammo forza</a><b> ·</b> <a href="/wiki/Secondo" title="Secondo">secondo</a></td></tr><tr><th class="subnavbox_group" style="text-align:center; width:22%;">Unità derivate</th><td colspan="1"><a href="/wiki/Unit%C3%A0_tecnica_di_massa" title="Unità tecnica di massa">unità tecnica di massa</a></td></tr></tbody></table></td></tr><tr><th colspan="1" class="navbox_group" style="text-align:center; width:22%;"><a href="/wiki/Sistema_MTS" title="Sistema MTS">Sistema MTS</a></th><td colspan="1" class="navbox_list navbox_even"><table class="subnavbox"><tbody><tr><th class="subnavbox_group" style="text-align:center; width:22%;">Unità di base</th><td colspan="1"><a href="/wiki/Metro" title="Metro">metro</a><b> ·</b> <a href="/wiki/Tonnellata" title="Tonnellata">tonnellata</a><b> ·</b> <a href="/wiki/Secondo" title="Secondo">secondo</a></td></tr><tr><th class="subnavbox_group" style="text-align:center; width:22%;">Unità derivate</th><td colspan="1"><a href="/wiki/Sth%C3%A8ne" title="Sthène">sthène</a><b> ·</b> <a href="/wiki/Joule" title="Joule">chilojoule</a><b> ·</b> <a href="/wiki/Watt" title="Watt">chilowatt</a><b> ·</b> <a href="/wiki/Pi%C3%A8ze" title="Pièze">pièze</a></td></tr></tbody></table></td></tr><tr><th colspan="1" class="navbox_group" style="text-align:center; width:22%;"><a href="/wiki/Unit%C3%A0_atomiche" title="Unità atomiche">Unità atomiche</a></th><td colspan="1" class="navbox_list navbox_odd"><table class="subnavbox"><tbody><tr><th class="subnavbox_group" style="text-align:center; width:22%;">Unità di base</th><td colspan="1"><a href="/wiki/Raggio_di_Bohr" title="Raggio di Bohr">raggio di Bohr</a><b> ·</b> <a href="/wiki/Massa_a_riposo_dell%27elettrone" title="Massa a riposo dell'elettrone">massa a riposo dell'elettrone</a><b> ·</b> <a href="/wiki/Carica_elementare" title="Carica elementare">carica elementare</a><b> ·</b> <a href="/wiki/Costante_di_Planck#Valore" title="Costante di Planck">costante di Dirac</a><b> ·</b> <a href="/wiki/Energia_di_Hartree" title="Energia di Hartree">energia di Hartree</a></td></tr></tbody></table></td></tr><tr><th colspan="1" class="navbox_group" style="text-align:center; width:22%;"><a href="/wiki/Unit%C3%A0_di_misura_di_Planck" title="Unità di misura di Planck">Unità di misura di Planck</a></th><td colspan="1" class="navbox_list navbox_even"><table class="subnavbox"><tbody><tr><th class="subnavbox_group" style="text-align:center; width:22%;">Unità di base</th><td colspan="1"><a href="/wiki/Tempo_di_Planck" title="Tempo di Planck">tempo di Planck</a><b> ·</b> <a href="/wiki/Lunghezza_di_Planck" title="Lunghezza di Planck">lunghezza di Planck</a><b> ·</b> <a href="/wiki/Massa_di_Planck" title="Massa di Planck">massa di Planck</a><b> ·</b> <a href="/wiki/Carica_di_Planck" title="Carica di Planck">carica di Planck</a><b> ·</b> <a href="/wiki/Temperatura_di_Planck" title="Temperatura di Planck">temperatura di Planck</a><b> ·</b> <a href="/wiki/Costante_di_Planck" title="Costante di Planck">quanto del momento angolare</a></td></tr><tr><th class="subnavbox_group" style="text-align:center; width:22%;">Unità derivate</th><td colspan="1"><a href="/wiki/Energia_di_Planck" title="Energia di Planck">energia di Planck</a><b> ·</b> <a href="/wiki/Forza_di_Planck" class="mw-redirect" title="Forza di Planck">forza di Planck</a><b> ·</b> <a href="/wiki/Potenza_di_Planck" class="mw-redirect" title="Potenza di Planck">potenza di Planck</a><b> ·</b> <a href="/wiki/Densit%C3%A0_di_Planck" class="mw-redirect" title="Densità di Planck">densità di Planck</a><b> ·</b> <a href="/wiki/Frequenza_angolare_di_Planck" class="mw-redirect" title="Frequenza angolare di Planck">frequenza angolare di Planck</a><b> ·</b> <a href="/wiki/Pressione_di_Planck" class="mw-redirect" title="Pressione di Planck">pressione di Planck</a><b> ·</b> <a href="/wiki/Corrente_di_Planck" class="mw-redirect" title="Corrente di Planck">corrente di Planck</a><b> ·</b> <a href="/wiki/Tensione_di_Planck" class="mw-redirect" title="Tensione di Planck">tensione di Planck</a><b> ·</b> <a href="/wiki/Resistenza_di_Planck" class="mw-redirect" title="Resistenza di Planck">resistenza di Planck</a></td></tr></tbody></table></td></tr><tr><th colspan="1" class="navbox_group" style="text-align:center; width:22%;">Altre unità di misura</th><td colspan="1" class="navbox_list navbox_odd"><table class="subnavbox"><tbody><tr><th class="subnavbox_group" style="text-align:center; width:22%;"><a href="/wiki/Area" title="Area">Area</a></th><td colspan="1"><a href="/wiki/Ettaro" title="Ettaro">ettaro</a></td></tr><tr><th class="subnavbox_group" style="text-align:center; width:22%;"><a href="/wiki/Densit%C3%A0_lineare" title="Densità lineare">Densità lineare</a></th><td colspan="1"><a href="/wiki/Denaro_(unit%C3%A0_di_misura)" title="Denaro (unità di misura)">denaro</a><b> ·</b> <a href="/wiki/Tex_(unit%C3%A0_di_misura)" title="Tex (unità di misura)">tex</a></td></tr><tr><th class="subnavbox_group" style="text-align:center; width:22%;"><a href="/wiki/Entropia" title="Entropia">Entropia</a></th><td colspan="1"><a href="/wiki/Clausius_(unit%C3%A0_di_misura)" title="Clausius (unità di misura)">clausius</a></td></tr><tr><th class="subnavbox_group" style="text-align:center; width:22%;"><a href="/wiki/Massa_(fisica)" title="Massa (fisica)">Massa</a></th><td colspan="1"><a href="/wiki/Grano_(unit%C3%A0_di_misura)" title="Grano (unità di misura)">grano</a><b> ·</b> <a href="/wiki/Scruple" title="Scruple">scruple</a><b> ·</b> <a href="/wiki/Dramma_(unit%C3%A0_di_misura)" title="Dramma (unità di misura)">dramma</a><b> ·</b> <a href="/wiki/Oncia_(unit%C3%A0_di_misura)" title="Oncia (unità di misura)">oncia</a><b> ·</b> <a href="/wiki/Libbra" title="Libbra">libbra</a><b> ·</b> <a href="/wiki/Pietra_(unit%C3%A0_di_misura)" class="mw-redirect" title="Pietra (unità di misura)">pietra</a><b> ·</b> <a href="/wiki/Quarto_(unit%C3%A0_di_misura)" title="Quarto (unità di misura)">quarto</a><b> ·</b> <a href="/wiki/Slug_(unit%C3%A0_di_misura)" title="Slug (unità di misura)">slug</a></td></tr><tr><th class="subnavbox_group" style="text-align:center; width:22%;"><a href="/wiki/Temperatura" title="Temperatura">Temperatura</a></th><td colspan="1"><a href="/wiki/Grado_R%C3%B8mer" title="Grado Rømer">grado Rømer</a></td></tr><tr><th class="subnavbox_group" style="text-align:center; width:22%;"><a href="/wiki/Energia" title="Energia">Energia</a></th><td colspan="1"><a href="/wiki/Caloria" title="Caloria">caloria</a><b> ·</b> <a href="/wiki/Frigoria" title="Frigoria">frigoria</a></td></tr><tr><th class="subnavbox_group" style="text-align:center; width:22%;"><a href="/wiki/Lunghezza" title="Lunghezza">lunghezza</a> in astronomia</th><td colspan="1"><a href="/wiki/Unit%C3%A0_astronomica" title="Unità astronomica">unità astronomica</a><b> ·</b> <a href="/wiki/Anno_luce" title="Anno luce">anno luce</a><b> ·</b> <a href="/wiki/Parsec" title="Parsec">parsec</a></td></tr></tbody></table></td></tr></tbody></table> <div class="noprint" style="width:100%; padding: 3px 0; display: flex; flex-wrap: wrap; row-gap: 4px; column-gap: 8px; box-sizing: border-box;"><div style="flex-grow: 1"><style data-mw-deduplicate="TemplateStyles:r140555418">.mw-parser-output .itwiki-template-occhiello{width:100%;line-height:25px;border:1px solid #CCF;background-color:#F0EEFF;box-sizing:border-box}.mw-parser-output .itwiki-template-occhiello-progetto{background-color:#FAFAFA}@media screen{html.skin-theme-clientpref-night .mw-parser-output .itwiki-template-occhiello{background-color:#202122;border-color:#54595D}html.skin-theme-clientpref-night .mw-parser-output .itwiki-template-occhiello-progetto{background-color:#282929}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .itwiki-template-occhiello{background-color:#202122;border-color:#54595D}html.skin-theme-clientpref-os .mw-parser-output .itwiki-template-occhiello-progetto{background-color:#282929}}</style><div class="itwiki-template-occhiello"><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Unbalanced_scales_simpler.svg" class="mw-file-description" title="Metrologia"><img alt=" " src="//upload.wikimedia.org/wikipedia/commons/thumb/1/17/Unbalanced_scales_simpler.svg/25px-Unbalanced_scales_simpler.svg.png" decoding="async" width="25" height="22" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/1/17/Unbalanced_scales_simpler.svg/38px-Unbalanced_scales_simpler.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/1/17/Unbalanced_scales_simpler.svg/50px-Unbalanced_scales_simpler.svg.png 2x" data-file-width="400" data-file-height="354" /></a></span> <b><a href="/wiki/Portale:Metrologia" title="Portale:Metrologia">Portale Metrologia</a></b>: accedi alle voci di Wikipedia che trattano di metrologia</div></div></div> <!-- NewPP limit report Parsed by mw‐web.eqiad.main‐7c479b968‐lbvqt Cached time: 20241117124453 Cache expiry: 2592000 Reduced expiry: false Complications: [show‐toc] CPU time usage: 0.293 seconds Real time usage: 0.421 seconds Preprocessor visited node count: 4161/1000000 Post‐expand include size: 65483/2097152 bytes Template argument size: 4494/2097152 bytes Highest expansion depth: 15/100 Expensive parser function count: 6/500 Unstrip recursion depth: 1/20 Unstrip post‐expand size: 10646/5000000 bytes Lua time usage: 0.151/10.000 seconds Lua memory usage: 5418234/52428800 bytes Number of Wikibase entities loaded: 0/400 --> <!-- Transclusion expansion time report (%,ms,calls,template) 100.00% 312.326 1 -total 33.26% 103.870 1 Template:Unità 32.27% 100.790 1 Template:Infobox 19.01% 59.362 1 Template:Unità_di_misura 18.35% 57.325 1 Template:Navbox 13.42% 41.923 12 Template:M 11.97% 37.378 1 Template:F 11.40% 35.597 1 Template:Avviso 10.81% 33.771 1 Template:Portale 10.00% 31.232 7 Template:Cita_web --> <!-- Saved in parser cache with key itwiki:pcache:idhash:63420-0!canonical and timestamp 20241117124453 and revision id 141231684. 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