Chromium | Uses, Properties, & Facts

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position-relative text-right d-flex align-items-center"> <div class="tlr-title px-20 py-15 text-left"> <em class="material-icons text-gray-400 d-lg-none" data-icon="toc"></em> <a class="font-serif font-weight-bold text-black link-blue" href="https://www.britannica.com/science/chromium">chromium</a> </div> <button aria-label="Close" class="js-sections-close-button btn-link btn-sm btn d-lg-none position-absolute top-0 p-10 right-0" > <em class="material-icons font-26" data-icon="close"></em> </button> </div> <div class="section-content pl-10 pr-20 pl-sm-50 pr-sm-60 pl-lg-5 pr-lg-10 pt-10 pt-lg-0 bg-gray-50 clear-catfish-ad"> <div class="toc mb-20"> <div class="font-serif font-14 font-weight-bold mx-15 mb-15 mt-20"> Table of Contents </div> <ul class="list-unstyled my-0" data-level="h1"><li data-target="#ref1"><div class="pl-25"><a class="link-gray-900 w-100" href="/science/chromium">Introduction</a></div><div class="ml-40 toc-drawer sub-toc-drawer"></div></li><li data-target="#ref8365"><div class="d-flex align-items-center"><div class="ml-25"></div><a class="w-100 link-gray-900" href="/science/chromium#ref8365">Occurrence, uses, and properties</a></div><div class="ml-40 toc-drawer sub-toc-drawer"></div></li><li data-target="#ref8366"><div class="d-flex align-items-center"><div class="ml-25"></div><a class="w-100 link-gray-900" href="/science/chromium#ref8366">Principal compounds</a></div><div class="ml-40 toc-drawer sub-toc-drawer"></div></li></ul> <a class="toc-extra-link link-gray-900" href="https://www.britannica.com/science/chromium/additional-info">References & Edit History</a> <a class="toc-extra-link link-gray-900" href="/facts/chromium">Quick Facts & Related Topics</a> </div> <div class="tlr-media-slider pb-10 mb-30"> <a class="section-header link-gray-900 font-serif font-14 font-weight-bold mb-10 mx-10" href="https://www.britannica.com/science/chromium/images-videos">Images</a> <div class="slider js-slider position-relative 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Chan School of Public Health - The Nutrition Source - Chromium</a></li> <li><a class="external" href="https://sites.dartmouth.edu/toxmetal/more-metals/chromium-a-thoroughly-modern-metal/the-facts-on-chromium/" target="_blank" rel="noopener ">Dartmouth College - Dartmouth Toxic Metals - The Facts on Chromium</a></li> <li><a class="external" href="https://ods.od.nih.gov/factsheets/Chromium-HealthProfessional/" target="_blank" rel="noopener ">National Institutes of Health - Office of Dietary Supplements - Chromium</a></li> <li><a class="external" href="https://chem.libretexts.org/Bookshelves/Inorganic_Chemistry/Map%3A_Inorganic_Chemistry_(Housecroft)/21%3A_d-Block_Metal_Chemistry_-_The_First_Row_Metals/21.07%3A_Group_6_-_Chromium/21.7A%3A_Chromium_Metal" target="_blank" rel="noopener ">Chemistry LibreTexts - Chromium Metal</a></li> <li><a class="external" href="https://pubchem.ncbi.nlm.nih.gov/element/Chromium" target="_blank" rel="noopener ">National Center of Biotechnology Information - PubChem - Chromium</a></li> <li><a class="external" href="https://health.clevelandclinic.org/chromium" target="_blank" rel="noopener ">Cleveland Clinic - Skip the Supplement: You Don’t Need More Chromium</a></li> <li><a class="external" href="https://www.webmd.com/vitamins/ai/ingredientmono-932/chromium" target="_blank" rel="noopener ">WebMD - Chromium - Uses, Side Effects, and More</a></li> </ul> </div> <div class="md-websites-ebk-title">Britannica Websites</div> <div class="md-websites-ebk-subtitle">Articles from Britannica Encyclopedias for elementary and high school students.</div> <ul class="list-unstyled bps-topic-web-sites lh-lg"> <li><a class="external" href="https://kids.britannica.com/students/article/chromium/273664" target="_blank" rel="noopener">chromium - Student Encyclopedia (Ages 11 and up)</a></li> </ul> </div> </div> </div> </div> <div class="toc-header-marker"></div> <button class="ai-ask-button btn btn-sm border-2 btn-outline-red-400 border-red-400 d-none mr-0 mr-lg-10 ml-5 ml-sm-10 ml-lg-0 p-10 px-sm-5 px-md-10 js-header-ai-ask-button"> Ask the Chatbot a Question </button> <div class="caption alternate-titles">Also known as: Cr</div> <div class="md-byline module-spacing "> <div class="font-serif font-12"> <span class="written-by text-gray-700"> Written by </span> <div class="editor-popover popover p-0"> <a class="d-block p-20 qa-editor-popup gtm-byline font-12 byline-contributor" href="/editor/Erik-Gregersen/6723" > <div class="editor-title font-16 font-weight-bold">Erik Gregersen</div> <div class="editor-description font-12 font-serif mt-5 clamp-description text-black">Erik Gregersen is a senior editor at Encyclopaedia Britannica, specializing in the physical sciences and technology. Before joining Britannica in 2007, he worked at the University of Chicago Press on the...</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"> Erik Gregersen</span></div> <div class="font-serif font-12 text-gray-700"> <span class="qa-fact-checked-by">Fact-checked by</span> <div class="editor-popover popover p-0"> <a class="d-block p-20 qa-editor-popup font-12" href="/editor/The-Editors-of-Encyclopaedia-Britannica/4419" > <div class="editor-title font-16 font-weight-bold">The Editors of Encyclopaedia Britannica</div> <div class="editor-description font-12 font-serif mt-5 text-black">Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree. 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 font-12 "> The Editors of Encyclopaedia Britannica</span></div> <div class="last-updated font-12 font-serif"> <span class="text-gray-700"> Last Updated: <time datetime="2025-02-24T00:00:00CST" >Feb 24, 2025</time> •</span> <a class="byline-edit-history" href="https://www.britannica.com/science/chromium/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 btn-sm border-2 btn-outline-red-400 border-red-400 module-spacing js-inline-ai-ask-button p-10 ml-5"> Ask the Chatbot </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/Nicolas-Louis-Vauquelin" topicid="624185">Nicolas-Louis Vauquelin</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/chemical-element" topicid="108636">chemical element</a></dd> <dd><a href="/science/transition-metal" topicid="602775">transition metal</a></dd> <dd><a href="/technology/chromium-processing" topicid="116008">chromium processing</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/chromium"> 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="ref271212"></span>chromium (Cr)</strong>, <a href="https://www.britannica.com/science/chemical-element" class="md-crosslink autoxref " data-show-preview="true">chemical element</a> of Group 6 (VIb) of the <a href="https://www.britannica.com/science/periodic-table" class="md-crosslink autoxref " data-show-preview="true">periodic table</a>, a hard steel-gray <a href="https://www.britannica.com/science/metal-chemistry" class="md-crosslink autoxref " data-show-preview="true">metal</a> that takes a high polish and is used in alloys to increase strength and <a href="https://www.britannica.com/science/corrosion" class="md-crosslink autoxref " data-show-preview="true">corrosion</a> resistance. Chromium was discovered (1797) by the French chemist <span id="ref271213"></span><a href="https://www.britannica.com/biography/Nicolas-Louis-Vauquelin" class="md-crosslink " data-show-preview="true">Nicolas-Louis Vauquelin</a> and isolated as the metal a year later; it was named for its multicoloured <a class="md-dictionary-link md-dictionary-tt-off mw" data-term="compounds" href="https://www.merriam-webster.com/dictionary/compounds" data-type="MW">compounds</a>. The green <a href="https://www.britannica.com/science/color" class="md-crosslink autoxref " data-show-preview="true">colour</a> of <a href="https://www.britannica.com/topic/emerald-gemstone" class="md-crosslink autoxref " data-show-preview="true">emerald</a>, serpentine, and chrome mica and the red colour of <a href="https://www.britannica.com/topic/ruby" class="md-crosslink autoxref " data-show-preview="true">ruby</a> are due to small amounts of chromium. The name of the element chromium (from Greek <em>chrōmos</em>, “colour”) connotes the pronounced and varied colorations of chromium compounds.</p><span class="marker MOD1 mod-inline"></span><div class="text-center pb-20"><div class="md-table-wrapper"><table class="md-element-table"><caption>Element Properties</caption><tbody><tr><th scope="row">atomic number</th><td>24</td></tr><tr><th scope="row">atomic weight</th><td>51.9961</td></tr><tr><th scope="row">melting point</th><td>1,890 °C (3,434 °F)</td></tr><tr><th scope="row">boiling point</th><td>2,482 °C (4,500 °F)</td></tr><tr><th scope="row">specific gravity</th><td>7.20 (28 °C)</td></tr><tr><th scope="row">oxidation states</th><td>+2, +3, +6</td></tr><tr><th scope="row">electron configuration</th><td>[Ar]3<em>d</em><sup>5</sup>4<em>s</em><sup>1</sup></td></tr></tbody></table></div></div></section> <span class="marker h2"></span><section data-level="1" id="ref8365"> <h2 class="h1">Occurrence, uses, and properties</h2> <span class="marker PREMOD2 mod-inline"></span><p class="topic-paragraph">Chromium is a relatively abundant element in Earth’s crust; the free metal is never found in nature. Most ores consist of the mineral <a href="https://www.britannica.com/science/chromite" class="md-crosslink autoxref " data-show-preview="true">chromite</a>, the ideal formula of which is FeCr<sub>2</sub><a href="https://www.britannica.com/science/oxygen" class="md-crosslink autoxref " data-show-preview="true">O</a><sub>4</sub>. It is widely dispersed in natural deposits, which are usually contaminated with oxygen, <a href="https://www.britannica.com/science/magnesium" class="md-crosslink autoxref " data-show-preview="true">magnesium</a>, <a href="https://www.britannica.com/science/aluminum" class="md-crosslink autoxref " data-show-preview="true">aluminum</a>, and silica; their chromium content varies from 42 to 56 percent. One of the chief uses of chromium is in ferrous <a class="md-dictionary-link md-dictionary-tt-off eb" data-term="alloys" href="https://www.britannica.com/dictionary/alloys" data-type="EB">alloys</a>, for which the pure metal is not required. Accordingly, chromite is often reduced with <a href="https://www.britannica.com/science/carbon-chemical-element" class="md-crosslink autoxref " data-show-preview="true">carbon</a> in a furnace, producing the <a href="https://www.britannica.com/technology/alloy" class="md-crosslink autoxref " data-show-preview="true">alloy</a> ferrochromium, which contains <a href="https://www.britannica.com/science/iron-chemical-element" class="md-crosslink autoxref " data-show-preview="true">iron</a> and chromium in an atom ratio of approximately 1 to 2.</p><span class="marker MOD2 mod-inline"></span> <span class="marker PREMOD3 mod-inline"></span><p class="topic-paragraph">To obtain pure chromium, chromite is first treated with molten alkali and oxygen, converting all of the chromium to the alkali chromate, and the latter is dissolved in water and eventually precipitated as <a href="https://www.britannica.com/science/sodium" class="md-crosslink autoxref " data-show-preview="true">sodium</a> dichromate, Na<sub>2</sub>Cr<sub>2</sub>O<sub>7</sub>. The dichromate is then reduced with carbon to chromium sesquioxide, Cr<sub>2</sub>O<sub>3</sub>, and that oxide in turn is reduced with aluminum to give the chromium metal.</p><a class="link-module shadow-sm d-block qa-quiz-module" href="/quiz/facts-you-should-know-the-periodic-table-quiz" data-link-module-iframe-link=""> <img loading="lazy" src="https://cdn.britannica.com/58/203458-131-D94E9327/periodic-table-concept.jpg" alt="Periodic Table of the elements concept image (chemistry)" class="rounded-sm mr-15" width="70" /> <div class="line-clamp clamp-5"> <div class="module-title bg-green">Britannica Quiz</div> <div class="font-weight-semi-bold mt-5">Facts You Should Know: The Periodic Table Quiz</div> </div> </a><span class="marker MOD3 mod-inline"></span> <span class="marker PREMOD4 mod-inline"></span><p class="topic-paragraph">Chromium is added to iron and <a href="https://www.britannica.com/science/nickel-chemical-element" class="md-crosslink autoxref " data-show-preview="true">nickel</a> in the form of <span id="ref271214"></span><a href="https://www.britannica.com/technology/ferrochromium" class="md-crosslink " data-show-preview="true">ferrochromium</a> to produce alloys specially <a class="md-dictionary-link md-dictionary-tt-off eb" data-term="characterized" href="https://www.britannica.com/dictionary/characterized" data-type="EB">characterized</a> by their high resistance to corrosion and oxidation. Used in small amounts, chromium hardens steel. Stainless steels are alloys of chromium and iron in which the chromium content varies from 10 to 26 percent. Chromium alloys are used to fabricate such products as oil tubing, automobile trim, and cutlery. Chromite is used as a <a href="https://www.britannica.com/technology/refractory" class="md-crosslink autoxref " data-show-preview="true">refractory</a> and as a raw material for the production of chromium chemicals.</p><span class="marker MOD4 mod-inline"></span> <span class="marker PREMOD5 mod-inline"></span><p class="topic-paragraph">The metal is white, hard, lustrous, and brittle and is extremely resistant to ordinary corrosive reagents; this resistance accounts for its extensive use as an electroplated protective coating. At elevated temperatures chromium unites directly with the halogens or with <a href="https://www.britannica.com/science/sulfur" class="md-crosslink autoxref " data-show-preview="true">sulfur</a>, <a href="https://www.britannica.com/science/silicon" class="md-crosslink autoxref " data-show-preview="true">silicon</a>, <a href="https://www.britannica.com/science/boron-chemical-element" class="md-crosslink autoxref " data-show-preview="true">boron</a>, <a href="https://www.britannica.com/science/nitrogen" class="md-crosslink autoxref " data-show-preview="true">nitrogen</a>, carbon, or oxygen. (For additional <a class="md-dictionary-link md-dictionary-tt-off eb" data-term="treatment" href="https://www.britannica.com/dictionary/treatment" data-type="EB">treatment</a> of chromium metal and its production, <em>see</em> <a href="https://www.britannica.com/technology/chromium-processing" class="md-crosslink " data-show-preview="true">chromium processing</a>.)</p><span class="marker MOD5 mod-inline"></span> <span class="marker PREMOD6 mod-inline"></span><p class="topic-paragraph">Natural chromium consists of a mixture of four stable isotopes: chromium-52 (83.76 percent), chromium-53 (9.55 percent), chromium-50 (4.31 percent), and chromium-54 (2.38 percent). The metal is paramagnetic (weakly attracted to a magnet). It exists in two forms: body-centred cubic (alpha) and hexagonal close-packed (beta). At room temperature, chromium slowly dissolves in hydrochloric and dilute sulfuric acids. Certain oxidizing agents produce a thin unreactive oxide layer on the metal, rendering it passive also to dilute mineral acids, such as sulfuric, nitric, or cold <a href="https://www.britannica.com/science/aqua-regia" class="md-crosslink autoxref " data-show-preview="true">aqua regia</a>. At ordinary temperatures the metal shows no reaction to seawater or to wet or dry air.</p><span class="marker MOD6 mod-inline"></span> <span class="marker PREMOD7 mod-inline"></span><p class="topic-paragraph">Top producers of chromium include <a href="https://www.britannica.com/place/South-Africa" class="md-crosslink autoxref " data-show-preview="true">South Africa</a>, India, Kazakhstan, and Turkey.</p><div class="module-spacing"> <DIV class="marketing-INLINE_SUBSCRIPTION marketing-content" data-marketing-id="INLINE_SUBSCRIPTION"><style> .student-promo-banner-wrapper { container-type: inline-size; margin-bottom: 15px; } @container (min-width: 475px) { .student-promo-banner { flex-direction: row; } .student-promo-banner-img-wrapper { margin-bottom: 0; margin-right: 10px; justify-content: flex-start; } .student-promo-banner-text-wrapper { text-align: left; margin-bottom: 0px; margin-left: 10px; } .student-promo-banner-button-wrapper { margin-right: 0; } }</style> <div class="student-promo-banner-wrapper"> <div class="student-promo-banner d-flex flex-column align-items-center bg-blue rounded p-20"> <div class="student-promo-banner-img-wrapper mb-20 mr-0 d-flex justify-content-center"> <img class="rounded" style="max-width: 100px; min-width: 80px" src="https://cdn.britannica.com/marketing/BlueThistle.webp" /> </div> <div class="student-promo-banner-text-wrapper ml-0 mb-10 text-center text-white"> <div class="h2 mb-10">Get Unlimited Access</div> <div class="h4 font-weight-semi-bold">Try Britannica Premium for free and discover more.</div> </div> <div class="student-promo-banner-button-wrapper d-flex justify-content-center align-items-center ml-auto mr-auto"> <a class="btn btn-m btn-orange" href="https://premium.britannica.com/premium-membership/?utm_source=premium&utm_medium=inline-cta&utm_campaign=august-2024">Subscribe</a> </div> </div> </div> </DIV></div><span class="marker MOD7 mod-inline"></span> <div class="mb-20"><div class="w-100"><figure class="md-assembly m-0 mb-md-0 card card-borderless print-false" data-assembly-id="299687" data-asm-type="infogram"><div class="md-assembly-wrapper card-media" data-type="infogram"><script id="infogram_0__/z8pqlTWwRHqAnaNwFRkn" src="https://e.infogram.com/js/dist/embed.js?Itp" type="text/javascript" title="Explore an interactive periodic table of the elements"></script></div></figure></div></div> </section> <span class="marker h3"></span><section data-level="1" id="ref8366"> <h2 class="h1">Principal compounds</h2> <span class="marker PREMOD9 mod-inline"></span><p class="topic-paragraph">The most common oxidation states of chromium are +6, +3, and +2. A few stable compounds of the +5, +4, and +1 states, however, are known.</p><span class="marker MOD9 mod-inline"></span> <span class="marker PREMOD10 mod-inline"></span><p class="topic-paragraph">In the +6 <a href="https://www.britannica.com/science/oxidation-number" class="md-crosslink autoxref " data-show-preview="true">oxidation state</a>, the most important species formed by chromium are the <span id="ref271215"></span><a href="https://www.britannica.com/science/chromate-mineral" class="md-crosslink " data-show-preview="true">chromate</a>, CrO<sub>4</sub><sup>2−</sup>, and <span id="ref271216"></span>dichromate, Cr<sub>2</sub>O<sub>7</sub><sup>2−</sup>, ions. These ions form the basis for a series of industrially important salts. Among them are sodium chromate, Na<sub>2</sub>CrO<sub>4</sub>, and sodium dichromate, Na<sub>2</sub>Cr<sub>2</sub>O<sub>7</sub>, which are used in <a href="https://www.britannica.com/topic/leather" class="md-crosslink autoxref " data-show-preview="true">leather</a> <a href="https://www.britannica.com/technology/tanning" class="md-crosslink autoxref " data-show-preview="true">tanning</a>, in metal surface treatment, and as <a class="md-dictionary-link md-dictionary-tt-off mw" data-term="catalysts" href="https://www.merriam-webster.com/dictionary/catalysts" data-type="MW">catalysts</a> in various industrial processes.</p><span class="marker MOD10 mod-inline"></span> <span class="marker PREMOD11 mod-inline"></span><p class="topic-paragraph">Chromium forms several commercially valuable oxygen compounds, the most important of which is chromium oxide, commonly called <span id="ref271217"></span>chromium trioxide or chromic acid, CrO<sub>3</sub>, in which chromium is in the +6 oxidation state. An orange-red <a href="https://www.britannica.com/science/crystal" class="md-crosslink autoxref " data-show-preview="true">crystalline solid</a>, chromic acid liquefies gradually when exposed to moist air. It is usually produced by treatment of sodium dichromate with <a href="https://www.britannica.com/science/sulfuric-acid" class="md-crosslink autoxref " data-show-preview="true">sulfuric acid</a>. Chromic acid is used chiefly for chromium plating but is also employed as a colorant in ceramics. It is a powerful oxidant and may react violently with some organic materials, but such solutions are often utilized by controlled oxidations in organic synthesis.</p><div class="one-good-fact-module"> </div><span class="marker MOD11 mod-inline"></span> <span class="marker PREMOD12 mod-inline"></span><p class="topic-paragraph">Another significant oxygen <a class="md-dictionary-link md-dictionary-tt-off mw" data-term="compound" href="https://www.merriam-webster.com/dictionary/compound" data-type="MW">compound</a> is chromium oxide, also known as <span id="ref271218"></span>chromium sesquioxide or chromic oxide, Cr<sub>2</sub>O<sub>3</sub>, in which chromium is in the +3 oxidation state. It is prepared by calcining sodium dichromate in the presence of carbon or sulfur. Chromium oxide is a green powder and is employed extensively as a pigment; its hydrate form, known as Guignet’s green, is used when chemical and heat resistance are required.</p><span class="marker MOD12 mod-inline"></span> </section> <span class="md-signature font-12"><a href="/editor/Erik-Gregersen/6723">Erik Gregersen</a></span> <span class="marker end-of-content"></span><span class="marker after-article"></span></div> <div id="chatbot-simplify-root"></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> 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":115973,"pageLength":798,"initialLoad":true,"lastPageOfScroll":false} </script> <script class="marketing-content-info" type="application/json"> [] </script> <script src="https://cdn.britannica.com/mendel-resources/3-134/js/libs/jquery-3.5.0.min.js?v=3.134.9"></script> <script type="text/javascript" data-type="Init Mendel Code Splitting"> (function() { $.ajax({ dataType: 'script', cache: true, url: 'https://cdn.britannica.com/mendel-resources/3-134/dist/topic-page.js?v=3.134.9' }); })(); </script> <script class="analytics-metadata" type="application/json"> {"leg":"A","adLeg":"A","userType":"ANONYMOUS","pageType":"Topic","pageSubtype":null,"articleTemplateType":"MEDIUM","gisted":false,"pageNumber":1,"hasSummarizeButton":false,"hasAskButton":true,"hasAiTopQuestions":false,"hasSimplifyButton":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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Chromium | Uses, Properties, & Facts | Britannica