Chemistry | Definition, Topics, Types, History, & Facts

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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/chemistry">Introduction & Top Questions</a></div><div class="ml-40 toc-drawer sub-toc-drawer"></div></li><li data-target="#ref32495"><div class="d-flex align-items-center"><button class="h1-link-drawer-button btn btn-xs btn-circle d-flex rounded" type="button" aria-label="Toggle Heading"><em class="material-icons font-18" data-icon="keyboard_arrow_right"></em></button><a class="w-100 link-gray-900" href="/science/chemistry#ref32495">The scope of chemistry</a></div><div class="ml-40 toc-drawer sub-toc-drawer"><ul class="list-unstyled" data-level="h2"><li data-target="#ref32496"><a class="w-100 link-gray-900" href="/science/chemistry/Analytical-chemistry">Analytical chemistry</a></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref32497"><a class="w-100 link-gray-900" href="/science/chemistry/Analytical-chemistry#ref32497">Inorganic chemistry</a></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref32498"><a class="w-100 link-gray-900" href="/science/chemistry/Analytical-chemistry#ref32498">Organic chemistry</a></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref32499"><a class="w-100 link-gray-900" href="/science/chemistry/Biochemistry">Biochemistry</a></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref32500"><a class="w-100 link-gray-900" href="/science/chemistry/Biochemistry#ref32500">Polymer chemistry</a></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref32501"><a class="w-100 link-gray-900" href="/science/chemistry/Biochemistry#ref32501">Physical chemistry</a></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref32502"><a class="w-100 link-gray-900" href="/science/chemistry/Biochemistry#ref32502">Industrial chemistry</a></li></ul></div></li><li data-target="#ref32503"><div class="d-flex align-items-center"><button class="h1-link-drawer-button btn btn-xs btn-circle d-flex rounded" type="button" aria-label="Toggle Heading"><em class="material-icons font-18" data-icon="keyboard_arrow_right"></em></button><a class="w-100 link-gray-900" href="/science/chemistry/The-methodology-of-chemistry">The methodology of chemistry</a></div><div class="ml-40 toc-drawer sub-toc-drawer"><ul class="list-unstyled" data-level="h2"><li data-target="#ref32504"><a class="w-100 link-gray-900" href="/science/chemistry/The-methodology-of-chemistry#ref32504">Studies of molecular structure</a><ul class="list-unstyled" data-level="h3"><li data-target="#ref32505"><a class="w-100 link-gray-900" href="/science/chemistry/The-methodology-of-chemistry#ref32505">Atoms and elements</a></li></ul><ul class="list-unstyled" data-level="h3"><li data-target="#ref32506"><a class="w-100 link-gray-900" href="/science/chemistry/The-methodology-of-chemistry#ref32506">Ionic and covalent bonding</a></li></ul><ul class="list-unstyled" data-level="h3"><li data-target="#ref32507"><a class="w-100 link-gray-900" href="/science/chemistry/Isomerism">Isomerism</a></li></ul></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref32508"><a class="w-100 link-gray-900" href="/science/chemistry/Isomerism#ref32508">Investigations of chemical transformations</a><ul class="list-unstyled" data-level="h3"><li data-target="#ref32509"><a class="w-100 link-gray-900" href="/science/chemistry/Isomerism#ref32509">Basic factors</a></li></ul><ul class="list-unstyled" data-level="h3"><li data-target="#ref32510"><a class="w-100 link-gray-900" href="/science/chemistry/Isomerism#ref32510">Energy and the first law of thermodynamics</a></li></ul><ul class="list-unstyled" data-level="h3"><li data-target="#ref32511"><a class="w-100 link-gray-900" href="/science/chemistry/Isomerism#ref32511">Entropy and the second law of thermodynamics</a></li></ul><ul class="list-unstyled" data-level="h3"><li data-target="#ref32512"><a class="w-100 link-gray-900" href="/science/chemistry/Isomerism#ref32512">Rates of reaction</a></li></ul></li></ul></div></li><li data-target="#ref32513"><div class="d-flex align-items-center"><div class="ml-25"></div><a class="w-100 link-gray-900" href="/science/chemistry/Chemistry-and-society">Chemistry and society</a></div><div class="ml-40 toc-drawer sub-toc-drawer"></div></li><li data-target="#ref259701"><div class="d-flex align-items-center"><button class="h1-link-drawer-button btn btn-xs btn-circle d-flex rounded" type="button" aria-label="Toggle Heading"><em class="material-icons font-18" data-icon="keyboard_arrow_right"></em></button><a class="w-100 link-gray-900" href="/science/chemistry/Chemistry-and-society#ref259701">The history of chemistry</a></div><div class="ml-40 toc-drawer sub-toc-drawer"><ul class="list-unstyled" data-level="h2"><li data-target="#ref259702"><a class="w-100 link-gray-900" href="/science/chemistry/Chemistry-and-society#ref259702">Philosophy of matter in antiquity</a></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref259703"><a class="w-100 link-gray-900" href="/science/chemistry/Alchemy">Alchemy</a></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref259704"><a class="w-100 link-gray-900" href="/science/chemistry/Alchemy#ref259704">Phlogiston theory</a></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref259705"><a class="w-100 link-gray-900" href="/science/chemistry/The-chemical-revolution">The chemical revolution</a></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref259706"><a class="w-100 link-gray-900" href="/science/chemistry/The-chemical-revolution#ref259706">Atomic and molecular theory</a></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref259707"><a class="w-100 link-gray-900" href="/science/chemistry/The-chemical-revolution#ref259707">Organic radicals and the theory of chemical structure</a></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref259708"><a class="w-100 link-gray-900" href="/science/chemistry/Mendeleevs-periodic-law">Mendeleev’s periodic law</a></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref259709"><a class="w-100 link-gray-900" href="/science/chemistry/Mendeleevs-periodic-law#ref259709">The rise of physical chemistry</a></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref259710"><a class="w-100 link-gray-900" href="/science/chemistry/Mendeleevs-periodic-law#ref259710">Electronic theories of valence</a></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref259711"><a class="w-100 link-gray-900" href="/science/chemistry/Biochemistry-polymers-and-technology">Biochemistry, polymers, and technology</a></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref259712"><a class="w-100 link-gray-900" href="/science/chemistry/Biochemistry-polymers-and-technology#ref259712">The instrumental revolution</a></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref259713"><a class="w-100 link-gray-900" href="/science/chemistry/Biochemistry-polymers-and-technology#ref259713">Organic chemistry in the 20th century</a></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref259714"><a class="w-100 link-gray-900" href="/science/chemistry/Biochemistry-polymers-and-technology#ref259714">Chemistry in the 21st century</a></li></ul></div></li></ul> <a class="toc-extra-link link-gray-900" 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Usselman</div> <div class="editor-description font-12 font-serif mt-5 clamp-description text-black">Associate Professor of Chemistry, University of Western Ontario, London.</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"> Melvyn C. Usselman</span>, <div class="editor-popover popover p-0"> <a class="d-block p-20 gtm-byline font-12 byline-contributor" href="/contributor/Alan-J-Rocke/4563" > <div class="editor-title font-16 font-weight-bold">Alan J. Rocke</div> <div class="editor-description font-12 font-serif mt-5 clamp-description text-black">Professor of History, Case Western Reserve University, Cleveland, Ohio, U.S. Author of <i>The Quiet Revolution: Hermann Kolbe and the Science of Organic Chemistry</i> and other books.</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"> Alan J. Rocke</span><span class="text-gray-700 mx-5">•</span><a class="see-all border-gray-700 gtm-byline" rel="nofollow" href="https://www.britannica.com/science/chemistry/additional-info#contributors">All</a> </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 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="2024-11-22T00:00:00CST" >Nov 22, 2024</time> •</span> <a class="byline-edit-history" href="https://www.britannica.com/science/chemistry/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/Joachim-Frank" topicid="2110091">Joachim Frank</a></dd> <dd><a href="/biography/Stephen-L-Buchwald" topicid="2251178">Stephen L. Buchwald</a></dd> <dd><a href="/biography/Alexei-Ekimov" topicid="2233151">Alexei Ekimov</a></dd> <dd><a href="/biography/John-F-Hartwig" topicid="2252649">John F. Hartwig</a></dd> <dd><a href="/biography/Meir-Lahav" topicid="2249758">Meir Lahav</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-bonding" topicid="684121">chemical bonding</a></dd> <dd><a href="/science/chemical-element" topicid="108636">chemical element</a></dd> <dd><a href="/science/chemical-compound" topicid="108614">chemical compound</a></dd> <dd><a href="/science/biochemistry" topicid="65785">biochemistry</a></dd> <dd><a href="/science/chemical-reaction" topicid="108802">chemical reaction</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>On the Web: </dt> <dd><a href="https://www.ijsr.net/archive/v12i7/SR23722172647.pdf" target="_blank">International Journal of Science and Research - Learning Skills of Junior High School Students and their Academic Performance in Chemistry</a> (Nov. 22, 2024)</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/chemistry"> See all related content </a> </div> </div> </div> </div><script type="application/ld+json"> { "@context": "https://schema.org", "@type": "FAQPage", "mainEntity": [ { "@type" : "Question", "name" : "<div>What is chemistry?<\/div><em><\/em>", "acceptedAnswer" : { "@type" : "Answer", "text" : "Chemistry is the branch of <a href=\"https:\/\/www.britannica.com\/science\/science\">science<\/a> that deals with the properties, composition, and structure of <a href=\"https:\/\/www.britannica.com\/science\/chemical-element\">elements<\/a> and <a href=\"https:\/\/www.britannica.com\/science\/chemical-compound\">compounds<\/a>, how they can change, and the <a href=\"https:\/\/www.britannica.com\/science\/energy\">energy<\/a> that is released or absorbed when they change. " } } , { "@type" : "Question", "name" : "<div>How are chemistry and biology related?<\/div><em><\/em>", "acceptedAnswer" : { "@type" : "Answer", "text" : "Chemistry is the study of substances\u2014that is, <a href=\"https:\/\/www.britannica.com\/science\/chemical-element\">elements<\/a> and <a href=\"https:\/\/www.britannica.com\/science\/chemical-compound\">compounds<\/a>\u2014while <a href=\"https:\/\/www.britannica.com\/science\/biology\">biology<\/a> is the study of living things. However, these two branches of <a href=\"https:\/\/www.britannica.com\/science\/science\">science<\/a> meet in the discipline of <a href=\"https:\/\/www.britannica.com\/science\/biochemistry\">biochemistry<\/a>, which studies the substances in living things and how they change within an organism." } } ] } </script> <div class="top-questions qa-accordion d-flex flex-column module-spacing"><div class="font-weight-bold font-14 mb-5"> Top Questions </div><div id="intent-accordion" class="md-intent-accordion"><div class="top-question bg-gray-50 rounded" data-value="1"><h3 class="accordion--question font-14 font-weight-normal cursor-pointer rounded"><div class="pe-none d-flex justify-content-between align-items-center"><div>What is chemistry?</div><em class="material-icons" data-icon="expand_more"></em></div></h3><div class="accordion--answer hidden p-15 pt-5 font-16 mb-5"><div class="accordion--answer-copy"><p>Chemistry is the branch of <a href="https://www.britannica.com/science/science" class="md-crosslink " data-show-preview="true">science</a> that deals with the properties, composition, and structure of <a href="https://www.britannica.com/science/chemical-element" class="md-crosslink " data-show-preview="true">elements</a> and <a href="https://www.britannica.com/science/chemical-compound" class="md-crosslink " data-show-preview="true">compounds</a>, how they can change, and the <a href="https://www.britannica.com/science/energy" class="md-crosslink " data-show-preview="true">energy</a> that is released or absorbed when they change. </p></div></div></div><div class="top-question bg-gray-50 rounded" data-value="2"><h3 class="accordion--question font-14 font-weight-normal cursor-pointer rounded"><div class="pe-none d-flex justify-content-between align-items-center"><div>How are chemistry and biology related?</div><em class="material-icons" data-icon="expand_more"></em></div></h3><div class="accordion--answer hidden p-15 pt-5 font-16 mb-5"><div class="accordion--answer-copy"><p>Chemistry is the study of substances—that is, <a href="https://www.britannica.com/science/chemical-element" class="md-crosslink " data-show-preview="true">elements</a> and <a href="https://www.britannica.com/science/chemical-compound" class="md-crosslink " data-show-preview="true">compounds</a>—while <a href="https://www.britannica.com/science/biology" class="md-crosslink " data-show-preview="true">biology</a> is the study of living things. However, these two branches of <a href="https://www.britannica.com/science/science" class="md-crosslink " data-show-preview="true">science</a> meet in the discipline of <a href="https://www.britannica.com/science/biochemistry" class="md-crosslink " data-show-preview="true">biochemistry</a>, which studies the substances in living things and how they change within an organism.</p></div></div></div></div></div><div class="bg-gray-50 p-15 rounded module-spacing recent-news d-flex flex-column float-false"> <div> <h2 class="font-weight-bold font-14 m-0 d-inline"> News <span class="text-gray-600">•</span> </h2> <div class="recent-news-item first-recent-news-item d-inline"> <a class="font-14 gtm-ap-news-link" href="https://www.scmp.com/news/people-culture/trending-china/article/3271669/china-boy-11-writes-600-lines-code-build-rocket-after-mastering-physics-chemistry" rel="nofollow">China boy, 11, masters physics, chemistry, writes code to build own rocket</a> <span class="font-14 text-gray-600"> <span>•</span> Nov. 2, 2024, 5:04 AM ET (South China Morning Post) </span> </div> </div> <div class="rest-of-recent-news-items"> <button class="js-toggle-recent-news d-flex btn btn-unstyled font-14 pr-10 rounded-sm mt-10" aria-label="Toggle additional news items"> Show less <em class="material-icons" data-icon="expand_less"></em> </button> </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="ref406817"></span>chemistry</strong>, the <a href="https://www.britannica.com/science/science" class="md-crosslink autoxref " data-show-preview="true">science</a> that deals with the properties, <a class="md-dictionary-link md-dictionary-tt-off mw" data-term="composition" href="https://www.merriam-webster.com/dictionary/composition" data-type="MW">composition</a>, and structure of substances (defined as elements and compounds), the transformations they undergo, and the <a href="https://www.britannica.com/science/energy" class="md-crosslink " data-show-preview="true">energy</a> that is released or absorbed during these processes. Every substance, whether naturally occurring or artificially produced, consists of one or more of the hundred-odd species of <a href="https://www.britannica.com/science/atom" class="md-crosslink " data-show-preview="true">atoms</a> that have been identified as elements. Although these atoms, in turn, are composed of more elementary particles, they are the basic building blocks of chemical substances; there is no quantity of <a href="https://www.britannica.com/science/oxygen" class="md-crosslink " data-show-preview="true">oxygen</a>, <a href="https://www.britannica.com/science/mercury-chemical-element" class="md-crosslink " data-show-preview="true">mercury</a>, or <a href="https://www.britannica.com/science/gold-chemical-element" class="md-crosslink " data-show-preview="true">gold</a>, for example, smaller than an <a href="https://www.britannica.com/science/atom" class="md-crosslink autoxref " data-show-preview="true">atom</a> of that substance. Chemistry, therefore, is concerned not with the <a href="https://www.britannica.com/science/subatomic-particle" class="md-crosslink " data-show-preview="true">subatomic domain</a> but with the properties of atoms and the laws governing their combinations and how the knowledge of these properties can be used to achieve specific purposes.</p><span class="marker MOD1 mod-inline"></span><span class="marker PREMOD2 mod-inline"></span><p class="topic-paragraph">The great challenge in chemistry is the development of a <a class="md-dictionary-link md-dictionary-tt-off mw" data-term="coherent" href="https://www.merriam-webster.com/dictionary/coherent" data-type="MW">coherent</a> explanation of the complex behaviour of materials, why they appear as they do, what gives them their enduring properties, and how interactions among different substances can bring about the formation of new substances and the destruction of old ones. From the earliest attempts to understand the material world in rational terms, chemists have struggled to develop theories of matter that satisfactorily explain both permanence and change. The ordered assembly of indestructible atoms into small and large <a href="https://www.britannica.com/science/molecule" class="md-crosslink " data-show-preview="true">molecules</a>, or extended networks of intermingled atoms, is generally accepted as the basis of permanence, while the reorganization of atoms or molecules into different arrangements lies behind theories of change. Thus chemistry involves the study of the atomic <a class="md-dictionary-link md-dictionary-tt-off eb" data-term="composition" href="https://www.britannica.com/dictionary/composition" data-type="EB">composition</a> and structural architecture of substances, as well as the varied interactions among substances that can lead to sudden, often violent reactions.</p><span class="marker MOD2 mod-inline"></span><span class="marker PREMOD3 mod-inline"></span><p class="topic-paragraph">Chemistry also is concerned with the utilization of natural substances and the creation of artificial ones. <a href="https://www.britannica.com/topic/cooking" class="md-crosslink " data-show-preview="true">Cooking</a>, <a href="https://www.britannica.com/science/fermentation" class="md-crosslink " data-show-preview="true">fermentation</a>, glass making, and <a href="https://www.britannica.com/science/metallurgy" class="md-crosslink " data-show-preview="true">metallurgy</a> are all chemical processes that date from the beginnings of civilization. Today, vinyl, Teflon, <a href="https://www.britannica.com/science/liquid-state-of-matter" class="md-crosslink autoxref " data-show-preview="true">liquid</a> crystals, <a href="https://www.britannica.com/science/semiconductor" class="md-crosslink " data-show-preview="true">semiconductors</a>, and superconductors represent the fruits of chemical technology. The 20th century saw dramatic advances in the comprehension of the marvelous and complex chemistry of living organisms, and a molecular interpretation of health and disease holds great promise. Modern chemistry, aided by increasingly sophisticated instruments, studies materials as small as single atoms and as large and complex as <a href="https://www.britannica.com/science/DNA" class="md-crosslink " data-show-preview="true">DNA</a> (deoxyribonucleic acid), which contains millions of atoms. New substances can even be designed to bear desired characteristics and then synthesized. The rate at which chemical knowledge continues to accumulate is remarkable. Over time more than 8,000,000 different chemical substances, both natural and artificial, have been characterized and produced. The number was less than 500,000 as recently as 1965.</p><span class="marker MOD3 mod-inline"></span><span class="marker PREMOD4 mod-inline"></span><p class="topic-paragraph">Intimately interconnected with the <a class="md-dictionary-link md-dictionary-tt-off mw" data-term="intellectual" href="https://www.merriam-webster.com/dictionary/intellectual" data-type="MW">intellectual</a> challenges of chemistry are those associated with industry. In the mid-19th century the German chemist <span id="ref406818"></span><a href="https://www.britannica.com/biography/Justus-Freiherr-von-Liebig" class="md-crosslink " data-show-preview="true">Justus von Liebig</a> commented that the wealth of a nation could be gauged by the amount of <span id="ref406819"></span><a href="https://www.britannica.com/science/sulfuric-acid" class="md-crosslink " data-show-preview="true">sulfuric acid</a> it produced. This acid, essential to many manufacturing processes, remains today the leading chemical product of industrialized countries. As Liebig recognized, a country that produces large amounts of sulfuric acid is one with a strong <a href="https://www.britannica.com/technology/chemical-industry" class="md-crosslink autoxref " data-show-preview="true">chemical industry</a> and a strong economy as a whole. The production, distribution, and utilization of a wide range of chemical products is common to all highly developed nations. In fact, one can say that the “iron age” of civilization is being replaced by a “polymer age,” for in some countries the total volume of <a href="https://www.britannica.com/science/polymer" class="md-crosslink " data-show-preview="true">polymers</a> now produced exceeds that of <a href="https://www.britannica.com/science/iron-chemical-element" class="md-crosslink " data-show-preview="true">iron</a>.</p><div class="one-good-fact-module"> </div><span class="marker MOD4 mod-inline"></span></section> <span class="marker h2"></span><section data-level="1" id="ref32495"><h2 class="h1">The scope of chemistry</h2> <span class="marker PREMOD5 mod-inline"></span><p class="topic-paragraph">The days are long past when one person could hope to have a detailed knowledge of all areas of chemistry. Those pursuing their interests into specific areas of chemistry communicate with others who share the same interests. Over time a group of chemists with specialized research interests become the founding members of an area of specialization. The areas of specialization that emerged early in the history of chemistry, such as organic, inorganic, <a href="https://www.britannica.com/science/physical-chemistry" class="md-crosslink " data-show-preview="true">physical</a>, <a class="md-dictionary-link md-dictionary-tt-off mw" data-term="analytical" href="https://www.merriam-webster.com/dictionary/analytical" data-type="MW">analytical</a>, and industrial chemistry, along with <a href="https://www.britannica.com/science/biochemistry" class="md-crosslink " data-show-preview="true">biochemistry</a>, remain of greatest general interest. There has been, however, much growth in the areas of polymer, environmental, and medicinal chemistry during the 20th century. Moreover, new specialities continue to appear, as, for example, pesticide, <a class="md-dictionary-link md-dictionary-tt-off mw" data-term="forensic" href="https://www.merriam-webster.com/dictionary/forensic" data-type="MW">forensic</a>, and computer chemistry.</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 MOD5 mod-inline"></span> </section><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":10,"pageId":108987,"pageLength":717,"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":"D","adLeg":"D","userType":"ANONYMOUS","pageType":"Topic","pageSubtype":null,"articleTemplateType":"PAGINATED","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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