{"id":168,"date":"2025-02-28T11:42:49","date_gmt":"2025-02-28T17:12:49","guid":{"rendered":"https:\/\/smardea.com\/?p=168"},"modified":"2025-04-08T11:24:30","modified_gmt":"2025-04-08T16:54:30","slug":"idea-of-atom-in-the-world","status":"publish","type":"post","link":"https:\/\/smardea.com\/?p=168","title":{"rendered":"Idea of Atom in the world."},"content":{"rendered":"\n<p>An <strong>atom<\/strong> is the basic building block of matter, the smallest unit of an element that retains the chemical properties of that element. Atoms are incredibly small, with a size on the order of 0.1 to 0.5 nanometers (1 nanometer = 10\u207b\u2079 meters). They consist of subatomic particles and are the foundation of all physical substances in the universe.<\/p>\n\n\n\n<h4 class=\"wp-block-heading has-pale-ocean-gradient-background has-background\">Key Properties<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Atomic Number<\/strong>: The number of protons, which defines the element (e.g., oxygen has 8 protons).<\/li>\n\n\n\n<li><strong>Mass Number<\/strong>: The total number of protons and neutrons.<\/li>\n\n\n\n<li><strong>Isotopes<\/strong>: Variants of an element with the same number of protons but different numbers of neutrons (e.g., Carbon-12 and Carbon-14).<\/li>\n\n\n\n<li><strong>Charge<\/strong>: Atoms are typically neutral because the number of protons equals the number of electrons. Ions form when this balance is disrupted.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading has-pale-ocean-gradient-background has-background\"><strong>Discovery and History of the Atom<\/strong><\/h3>\n\n\n\n<p class=\"has-white-background-color has-background\">The concept of the atom has evolved over centuries through scientific discoveries. The idea of an atom was first proposed by the Greek philosopher <strong>Democritus (460\u2013370 BCE)<\/strong>, who believed that all matter was composed of tiny, indivisible particles called &#8220;atomos.&#8221; However, this idea remained speculative until modern science provided experimental evidence<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>In <strong>1803, John Dalton<\/strong> proposed the first scientific atomic theory. He stated that atoms are indivisible, combine in fixed ratios to form compounds, and retain their identity in chemical reactions. Dalton&#8217;s theory laid the foundation for modern chemistry.<br><br>In <strong>1897, J.J. Thomson<\/strong> discovered the <strong>electron<\/strong> using a cathode ray tube, proving that atoms are divisible and contain smaller charged particles. He proposed the <strong>&#8220;plum pudding model,&#8221;<\/strong> where negatively charged electrons were embedded in a positively charged sphere.<br><br>In <strong>1911, Ernest Rutherford<\/strong> conducted the <strong>gold foil experiment<\/strong>, discovering that atoms have a small, dense, positively charged <strong>nucleus<\/strong> surrounded by empty space and orbiting electrons. This overturned Thomson\u2019s model.<br><br>In <strong>1913, Niels Bohr<\/strong> refined Rutherford\u2019s model, introducing the concept of <strong>electron shells<\/strong> or <strong>energy levels<\/strong>, stating that electrons move in fixed orbits around the nucleus.<br><br>In <strong>1932, James Chadwick<\/strong> discovered the <strong>neutron<\/strong>, completing the modern understanding of atomic structure.<\/p>\n<\/blockquote>\n\n\n\n<h3 class=\"wp-block-heading has-pale-ocean-gradient-background has-background\"><strong>Parts of an Atom<\/strong><\/h3>\n\n\n\n<p>An atom is composed of three primary subatomic particles:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Protons<\/strong>: Positively charged particles found in the nucleus (the central part of the atom). The number of protons (atomic number) determines the element (e.g., 1 for hydrogen, 6 for carbon).<\/li>\n\n\n\n<li><strong>Neutrons<\/strong>: Neutral particles (no charge) also located in the nucleus. The combined number of protons and neutrons is the atom&#8217;s mass number.<\/li>\n\n\n\n<li><strong>Electrons<\/strong>: Negatively charged particles that orbit the nucleus in electron shells or energy levels. Electrons are involved in chemical reactions and bonding.<\/li>\n<\/ol>\n\n\n\n<p>The nucleus, containing protons and neutrons, is extremely dense and accounts for nearly all of an atom&#8217;s mass, while the electron cloud surrounding it determines its size and chemical behaviour.<\/p>\n\n\n\n<p class=\"has-vivid-cyan-blue-color has-white-background-color has-text-color has-background has-link-color wp-elements-7f36f79ce36bbed8131de9190ff6e2d3\">The number of protons in an atom determines its <strong>atomic number<\/strong>, while the sum of protons and neutrons determines its <strong>atomic mass<\/strong>. Electrons balance the positive charge of protons, making the atom electrically neutral.<\/p>\n\n\n\n<h3 class=\"wp-block-heading has-pale-ocean-gradient-background has-background\"><strong>Atomic Structure<\/strong><\/h3>\n\n\n\n<p>The structure of an atom consists of:<\/p>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column has-pale-cyan-blue-background-color has-background is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:100%\">\n<ul class=\"wp-block-list has-white-background-color has-background\">\n<li><strong>Nucleus<\/strong> \u2013 The core of the atom containing protons and neutrons. It holds most of the atom\u2019s mass.<\/li>\n\n\n\n<li><strong>Electron Shells<\/strong> \u2013 Electrons are arranged in energy levels around the nucleus. The first shell holds up to 2 electrons, the second up to 8, and so on, following the <strong>2n\u00b2 rule<\/strong>.<\/li>\n\n\n\n<li><strong>Subatomic Forces<\/strong> \u2013 The nucleus is held together by the <strong>strong nuclear force<\/strong>, while electrons are attracted to the nucleus due to the <strong>electromagnetic force<\/strong>.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n\n\n\n<h3 class=\"wp-block-heading has-pale-ocean-gradient-background has-background\"><strong>Important Atomic Theories<\/strong><\/h3>\n\n\n\n<div class=\"wp-block-group has-white-background-color has-background\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<ul class=\"wp-block-list\">\n<li class=\"has-vivid-cyan-blue-color has-text-color has-link-color wp-elements-1b7275b62b2ddedfba16255cac4cba95\"><strong>Dalton\u2019s Atomic Theory (1803)<\/strong>\n<ul class=\"wp-block-list\">\n<li>Atoms are indivisible and indestructible.<\/li>\n\n\n\n<li>Atoms of the same element are identical.<\/li>\n\n\n\n<li>Atoms combine in simple ratios to form compounds.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li class=\"has-vivid-purple-color has-text-color has-link-color wp-elements-3cbcf15674134a81ba599f45cb6396f3\"><strong>Thomson\u2019s Model (1897)<\/strong>\n<ul class=\"wp-block-list\">\n<li>Atoms are made of a positive sphere with embedded negative electrons (plum pudding model).<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li class=\"has-vivid-cyan-blue-color has-text-color has-link-color wp-elements-2ba233a1bd0af54bc053c5675f48daf9\"><strong>Rutherford\u2019s Model (1911)<\/strong>\n<ul class=\"wp-block-list\">\n<li class=\"has-vivid-cyan-blue-color has-text-color has-link-color wp-elements-0267795cb55925968022ac37030bc05a\">Atoms have a dense, positively charged nucleus.<\/li>\n\n\n\n<li>Electrons move around the nucleus in empty space.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li class=\"has-vivid-purple-color has-text-color has-link-color wp-elements-6ed1810c2c439fd821efd176769d2b8c\"><strong>Bohr\u2019s Model (1913)<\/strong>\n<ul class=\"wp-block-list\">\n<li>Electrons move in fixed orbits with quantized energy levels.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li class=\"has-vivid-cyan-blue-color has-text-color has-link-color wp-elements-1d5e6a8f79d847b653a108e5935b2904\"><strong>Quantum Mechanical Model (1926)<\/strong>\n<ul class=\"wp-block-list\">\n<li>Proposed by Schr\u00f6dinger, this model describes electrons as <strong>probability clouds<\/strong> rather than fixed orbits.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/div><\/div>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Conclusion<\/strong><\/h3>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column has-cyan-bluish-gray-background-color has-background is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:100%\">\n<blockquote class=\"wp-block-quote is-style-plain is-layout-flow wp-block-quote-is-layout-flow\">\n<ul class=\"wp-block-list\">\n<li>The discovery of the atom and its structure revolutionized science, leading to advancements in nuclear energy, chemistry, medicine, and technology. The understanding of atomic behavior continues to shape innovations in quantum mechanics, nanotechnology, and space exploration.<\/li>\n<\/ul>\n<\/blockquote>\n<\/div>\n<\/div>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>An atom is the basic building block of matter, the smallest unit of an element that retains the chemical properties of that element. Atoms are incredibly small, with a size on the order of 0.1 to 0.5 nanometers (1 nanometer = 10\u207b\u2079 meters). They consist of subatomic particles and are the foundation of all physical&#8230;<\/p>\n","protected":false},"author":1,"featured_media":171,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"advanced_seo_description":"","jetpack_seo_html_title":"","jetpack_seo_noindex":false,"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"enabled":false},"version":2}},"categories":[11],"tags":[],"class_list":["post-168","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-inorganic-chemistry"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/smardea.com\/wp-content\/uploads\/2025\/02\/atom-68866_1920.jpg","jetpack_likes_enabled":true,"jetpack-related-posts":[],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/smardea.com\/index.php?rest_route=\/wp\/v2\/posts\/168","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/smardea.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/smardea.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/smardea.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/smardea.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=168"}],"version-history":[{"count":2,"href":"https:\/\/smardea.com\/index.php?rest_route=\/wp\/v2\/posts\/168\/revisions"}],"predecessor-version":[{"id":503,"href":"https:\/\/smardea.com\/index.php?rest_route=\/wp\/v2\/posts\/168\/revisions\/503"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/smardea.com\/index.php?rest_route=\/wp\/v2\/media\/171"}],"wp:attachment":[{"href":"https:\/\/smardea.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=168"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/smardea.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=168"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/smardea.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=168"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}