Ion | Definition, Chemistry, Examples, & Facts

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They write new content and verify and edit content received from contributors.</div> </a> <div data-popper-arrow></div> </div> <span class="btn btn-link editor-link p-0 qa-byline-link gtm-byline font-12 byline-contributor text-decoration-underline"> The Editors of Encyclopaedia Britannica</span></div> <div class="last-updated font-12 font-serif"> <span class="text-gray-700"> Last Updated: <time datetime="2024-11-06T00:00:00CST" >Nov 6, 2024</time> •</span> <a class="byline-edit-history" href="https://www.britannica.com/science/ion-physics/additional-info#history" rel="nofollow">Article History</a> </div></div> </div> <button class="d-flex d-lg-none btn btn-outline-blue border rounded-sm shadow-sm mobile-toc-button gtm-mobile-toc-inline-button d-none d-sm-block js-sections-inline-button module-spacing btn d-lg-none"> <em class="material-icons mr-5 ml-n10 my-n5 md-icon" data-icon="toc"></em> Table of Contents </button> <div class="d-flex d-sm-none flex-row"> <button class="d-flex d-lg-none btn btn-outline-blue border rounded-sm shadow-sm mobile-toc-button gtm-mobile-toc-inline-button js-sections-inline-button module-spacing"> <em class="material-icons mr-5 ml-n10 my-n5 md-icon" data-icon="toc"></em> Table of Contents </button> <button class="ai-ask-button btn border-2 ai-ask-button btn border-2 module-spacing btn-sm js-inline-ai-ask-button btn-outline-red-400 border-red-400 p-10 ml-5"> Ask the Chatbot a Question </button> </div> <div class="js-qf-module qf-module px-40 px-sm-20 py-15 mx-auto module-spacing font-14 bg-gray-50 rounded"> <div class="facts-list mt-10"> <div class=""> <div class="js-fact mb-10 line-clamp clamp-3"> <dl> <dt>Key People: </dt> <dd><a href="/biography/Dennis-Robert-Hoagland" topicid="268384">Dennis Robert Hoagland</a></dd> <dd><a href="/biography/David-Wineland" topicid="1885045">David Wineland</a></dd> <dd><a href="/biography/Wolfgang-Paul" topicid="446932">Wolfgang Paul</a></dd> <dd><a href="/biography/Pyotr-Petrovich-Lazarev" topicid="333196">Pyotr Petrovich Lazarev</a></dd> </dl> <button class="js-more-btn d-none btn btn-unstyled font-12 bg-gray-50" aria-label="Toggle more/less fact data"> <em class="js-content link-blue">(Show more)</em> </button> </div> </div> <div class=""> <div class="js-fact mb-10 line-clamp clamp-3"> <dl> <dt>Related Topics: </dt> <dd><a href="/science/carbanion" topicid="94652">carbanion</a></dd> <dd><a href="/science/carbonium-ion" topicid="95214">carbonium ion</a></dd> <dd><a href="/science/ionization" topicid="293007">ionization</a></dd> <dd><a href="/science/hydrogen-ion" topicid="278733">hydrogen ion</a></dd> <dd><a href="/science/heavy-ion" topicid="258934">heavy ion</a></dd> </dl> <button class="js-more-btn d-none btn btn-unstyled font-12 bg-gray-50" aria-label="Toggle more/less fact data"> <em class="js-content link-blue">(Show more)</em> </button> </div> <div class="text-center"> <a class="btn btn-sm btn-link p-0" href="/facts/ion-physics"> See all related content </a> </div> </div> </div> </div><span class="marker before-article"></span><section data-level="1" id="ref1"><span class="marker PREMOD1 mod-inline"></span><p class="topic-paragraph"><strong><span id="ref130516"></span>ion</strong>, any <a href="https://www.britannica.com/science/atom" class="md-crosslink autoxref " data-show-preview="true">atom</a> or group of atoms that bears one or more positive or negative electrical charges. Positively charged <a class="md-dictionary-link md-dictionary-tt-off eb" data-term="ions" href="https://www.britannica.com/dictionary/ions" data-type="EB">ions</a> are called <span id="ref130517"></span><a href="https://www.britannica.com/science/cation" class="md-crosslink " data-show-preview="true">cations</a>; negatively charged ions, <span id="ref130518"></span><a href="https://www.britannica.com/science/anion" class="md-crosslink " data-show-preview="true">anions</a>. Ions are formed by the addition of electrons to, or the removal of electrons from, neutral atoms or molecules or other ions; by combination of ions with other particles; or by rupture of a <a href="https://www.britannica.com/science/covalent-bond" class="md-crosslink autoxref " data-show-preview="true">covalent bond</a> between two atoms in such a way that both of the electrons of the bond are left in association with one of the formerly bonded atoms. Examples of these processes include the reaction of a <a href="https://www.britannica.com/science/sodium" class="md-crosslink autoxref " data-show-preview="true">sodium</a> atom with a <a href="https://www.britannica.com/science/chlorine" class="md-crosslink autoxref " data-show-preview="true">chlorine</a> atom to form a sodium <a href="https://www.britannica.com/science/cation" class="md-crosslink autoxref " data-show-preview="true">cation</a> and a chloride anion; the addition of a <a href="https://www.britannica.com/science/hydrogen" class="md-crosslink autoxref " data-show-preview="true">hydrogen</a> cation to an <a href="https://www.britannica.com/science/ammonia" class="md-crosslink autoxref " data-show-preview="true">ammonia</a> <a href="https://www.britannica.com/science/molecule" class="md-crosslink autoxref " data-show-preview="true">molecule</a> to form an ammonium cation; and the dissociation of a water molecule to form a hydrogen cation and a <a href="https://www.britannica.com/science/hydroxide" class="md-crosslink autoxref " data-show-preview="true">hydroxide</a> <a href="https://www.britannica.com/science/anion" class="md-crosslink autoxref " data-show-preview="true">anion</a>.</p><div class="one-good-fact-module"> </div><span class="marker MOD1 mod-inline"></span><span class="marker PREMOD2 mod-inline"></span><p class="topic-paragraph">Many crystalline substances are composed of ions held in regular geometric patterns by the attraction of the oppositely charged particles for each other. Ions <a class="md-dictionary-link md-dictionary-tt-off eb" data-term="migrate" href="https://www.britannica.com/dictionary/migrate" data-type="EB">migrate</a> under the influence of an electrical field and are the conductors of <a href="https://www.britannica.com/science/electric-current" class="md-crosslink autoxref " data-show-preview="true">electric current</a> in electrolytic cells.</p><span class="marker MOD2 mod-inline"></span></section> <span class="md-signature"><a href="/editor/The-Editors-of-Encyclopaedia-Britannica/4419">The Editors of Encyclopaedia Britannica</a></span> <span class="md-signature">This article was most recently revised and updated by <a href="/editor/Adam-Augustyn/6394">Adam Augustyn</a>.</span><span class="marker end-of-content"></span><span class="marker after-article"></span></div> <div id="chatbot-root"></div> </div> </div> </div> <div class="ai-dialog-placeholder"></div> </div> </div> <aside class="col-md-da-320"></aside> </div> </div> </div> </div> </article></div> </div></div> </div> </main> <div id="md-footer"></div> <noscript><iframe src="//www.googletagmanager.com/ns.html?id=GTM-5W6NC8" height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript> <script type="text/javascript" id="_informizely_script_tag"> var IzWidget = IzWidget || {}; (function (d) { var scriptElement = d.createElement('script'); scriptElement.type = 'text/javascript'; scriptElement.async = true; scriptElement.src = "https://insitez.blob.core.windows.net/site/f780f33e-a610-4ac2-af81-3eb184037547.js"; var node = d.getElementById('_informizely_script_tag'); node.parentNode.insertBefore(scriptElement, node); } )(document); </script>  <script> window.ap3c = window.ap3c || {}; var ap3c = window.ap3c; ap3c.cmd = ap3c.cmd || []; ap3c.cmd.push(function() { ap3c.init('ZO4siT4cLwnykPnzZWJtd3Byb2Q', 'https://engage.email.britannica.com/'); ap3c.track({v: 0}); }); ap3c.activity = function(act) { ap3c.act = (ap3c.act || []); ap3c.act.push(act); }; var s, t; s = document.createElement('script'); s.type = 'text/javascript'; s.src = "https://engage.email.britannica.com/app.js"; t = document.getElementsByTagName('script')[0]; t.parentNode.insertBefore(s, t); </script> <script class="marketing-page-info" type="application/json"> {"pageType":"Topic","templateName":"DESKTOP","pageNumber":1,"pagesTotal":1,"pageId":292705,"pageLength":186,"initialLoad":true,"lastPageOfScroll":false} </script> <script class="marketing-content-info" type="application/json"> [] </script> <script src="https://cdn.britannica.com/mendel-resources/3-130/js/libs/jquery-3.5.0.min.js?v=3.130.14"></script> <script type="text/javascript" data-type="Init Mendel Code Splitting"> (function() { $.ajax({ dataType: 'script', cache: true, url: 'https://cdn.britannica.com/mendel-resources/3-130/dist/topic-page.js?v=3.130.14' }); })(); </script> <script class="analytics-metadata" type="application/json"> {"leg":"A","adLeg":"A","userType":"ANONYMOUS","pageType":"Topic","pageSubtype":null,"articleTemplateType":"SMALL","gisted":false,"pageNumber":1,"hasSummarizeButton":false,"hasAskButton":false} </script> <script type="text/javascript"> EBStat={accountId:-1,hostnameOverride:'webstats.eb.com',domain:'www.britannica.com', json:''}; </script> <script type="text/javascript"> ( function() { $.ajax( { dataType: 'script', cache: true, url: '//www.britannica.com/webstats/mendelstats.js?v=1' } ) .done( function() { try {writeStat(null,EBStat);} catch(err){} } ); })(); </script> <div id="bc-fixed-dialogue"></div> </body> </html>

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Ion | Definition, Chemistry, Examples, & Facts | Britannica