{"id":3659,"date":"2023-01-09T10:11:33","date_gmt":"2023-01-09T10:11:33","guid":{"rendered":"https:\/\/9thclass.deltapublications.in\/?page_id=3659"},"modified":"2025-01-06T17:22:51","modified_gmt":"2025-01-06T17:22:51","slug":"s-4-e-atomic-number-and-mass-number","status":"publish","type":"page","link":"https:\/\/9thclass.deltapublications.in\/index.php\/s-4-e-atomic-number-and-mass-number\/","title":{"rendered":"S-4.e Atomic Number And Mass Number"},"content":{"rendered":"\n<h2 class=\"wp-block-heading has-text-align-center has-text-color\" style=\"color:#00056d;text-transform:uppercase\"><strong>Atomic Number And Mass Number<\/strong><\/h2>\n\n\n\n<p class=\"has-text-color has-link-color has-huge-font-size wp-elements-19f3e90c87bbc8a4106d5e7b6d862514\" style=\"color:#74008b\">Key notes :<\/p>\n\n\n\n<p class=\"has-text-align-center has-text-color has-background has-link-color has-large-font-size wp-elements-2a12625be2c71e425b42df642c79b302\" style=\"color:#000060;background-color:#dfc816\"><strong>Definition of an Atom<\/strong>:<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"562\" src=\"https:\/\/9thclass.deltapublications.in\/wp-content\/uploads\/2024\/11\/image-16.png\" alt=\"\" class=\"wp-image-15874\" style=\"width:339px;height:auto\" srcset=\"https:\/\/9thclass.deltapublications.in\/wp-content\/uploads\/2024\/11\/image-16.png 800w, https:\/\/9thclass.deltapublications.in\/wp-content\/uploads\/2024\/11\/image-16-300x211.png 300w, https:\/\/9thclass.deltapublications.in\/wp-content\/uploads\/2024\/11\/image-16-768x540.png 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><\/figure><\/div>\n\n\n<ul class=\"has-large-font-size wp-block-list\">\n<li>An atom is the smallest unit of an element that retains the chemical properties of that element.<\/li>\n\n\n\n<li>It is made up of subatomic particles: protons, neutrons, and electrons.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center has-text-color has-background has-link-color has-large-font-size wp-elements-5b4988c482ccdbf0e56b327bcd379151\" style=\"color:#000060;background-color:#dfc816\"><strong>Atomic Number (Z)<\/strong>:<\/p>\n\n\n\n<ul class=\"has-large-font-size wp-block-list\">\n<li>The <strong>atomic number<\/strong> is defined as the number of protons in the nucleus of an atom.<\/li>\n\n\n\n<li>It determines the element\u2019s identity and its position on the periodic table.<\/li>\n\n\n\n<li>For a neutral atom, the atomic number also equals the number of electrons.<\/li>\n\n\n\n<li>Example: Hydrogen has an atomic number of 1 (one proton), and carbon has an atomic number of 6 (six protons).<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center has-text-color has-background has-link-color has-large-font-size wp-elements-c3d9e0765fb354bc5e6877ecfa3a7b32\" style=\"color:#000060;background-color:#dfc816\"><strong>Mass Number (A)<\/strong>:<\/p>\n\n\n\n<ul class=\"has-large-font-size wp-block-list\">\n<li>The <strong>mass number<\/strong> is the total number of protons and neutrons in the nucleus of an atom.<\/li>\n\n\n\n<li>It is calculated as: <strong>Mass Number (A) = Number of Protons (Z) + Number of Neutrons (N)<\/strong>.<\/li>\n\n\n\n<li>Electrons have negligible mass, so they are not included in the mass number.<\/li>\n\n\n\n<li>Example: An oxygen atom with 8 protons and 8 neutrons has a mass number of 16.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center has-text-color has-background has-link-color has-large-font-size wp-elements-953d69dd132d7ad2d762519a1e132183\" style=\"color:#000060;background-color:#dfc816\"><strong>Notation<\/strong>:<\/p>\n\n\n\n<ul class=\"has-large-font-size wp-block-list\">\n<li>Atoms are often represented using the notation: Element&nbsp;Symbol A Z <\/li>\n<\/ul>\n\n\n\n<p class=\"has-large-font-size\"> where <strong>A<\/strong> is the mass number and <strong>Z<\/strong> is the atomic number.<\/p>\n\n\n\n<ul class=\"has-large-font-size wp-block-list\">\n<li>For example, carbon can be written as 12 6.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center has-text-color has-background has-link-color has-large-font-size wp-elements-6169cbbdeea143de66f3007da6c47bea\" style=\"color:#000060;background-color:#dfc816\"><strong>Isotopes<\/strong>:<\/p>\n\n\n\n<ul class=\"has-large-font-size wp-block-list\">\n<li><strong>Isotopes<\/strong> are atoms of the same element that have the same atomic number but different mass numbers due to varying numbers of neutrons.<\/li>\n\n\n\n<li>Example: Carbon-12 (<sup>1<\/sup>2C) and Carbon-14 (<sup>1<\/sup>4C) are isotopes of carbon with different numbers of neutrons.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center has-text-color has-background has-link-color has-large-font-size wp-elements-48c1af6e041b58af3c7e966a7fb49f96\" style=\"color:#000060;background-color:#dfc816\"><strong>Importance of Atomic Number<\/strong>:<\/p>\n\n\n\n<ul class=\"has-large-font-size wp-block-list\">\n<li>The atomic number determines the chemical properties of an element and its place in the periodic table.<\/li>\n\n\n\n<li>Elements are arranged in order of increasing atomic number.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center has-text-color has-background has-link-color has-large-font-size wp-elements-2639c791cfc113142ba0078f0cd4cbcc\" style=\"color:#000060;background-color:#dfc816\"><strong>Calculation Examples<\/strong>:<\/p>\n\n\n\n<ul class=\"has-large-font-size wp-block-list\">\n<li>If an atom has 11 protons and 12 neutrons:\n<ul class=\"wp-block-list\">\n<li>Atomic Number (Z) = 11<\/li>\n\n\n\n<li>Mass Number (A) = 11 + 12 = 23<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>This atom would be represented as 23 11 Na<\/li>\n<\/ul>\n\n\n\n<div class=\"wp-block-group has-large-font-size\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<p class=\"has-text-color has-large-font-size\" style=\"color:#d90000\">Let&#8217;s practice!<\/p>\n<\/div><\/div>\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 is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/wordwall.net\/play\/76019\/465\/446\"><img loading=\"lazy\" decoding=\"async\" width=\"500\" height=\"500\" src=\"https:\/\/9thclass.deltapublications.in\/wp-content\/uploads\/2023\/03\/Worksheet-1-2-18.png\" alt=\"\" class=\"wp-image-6391\" srcset=\"https:\/\/9thclass.deltapublications.in\/wp-content\/uploads\/2023\/03\/Worksheet-1-2-18.png 500w, https:\/\/9thclass.deltapublications.in\/wp-content\/uploads\/2023\/03\/Worksheet-1-2-18-300x300.png 300w, https:\/\/9thclass.deltapublications.in\/wp-content\/uploads\/2023\/03\/Worksheet-1-2-18-150x150.png 150w\" sizes=\"auto, (max-width: 500px) 100vw, 500px\" \/><\/a><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/wordwall.net\/play\/76049\/398\/857\"><img loading=\"lazy\" decoding=\"async\" width=\"500\" height=\"500\" src=\"https:\/\/9thclass.deltapublications.in\/wp-content\/uploads\/2023\/03\/Worksheet-1-1-1-19.png\" alt=\"\" class=\"wp-image-6392\" srcset=\"https:\/\/9thclass.deltapublications.in\/wp-content\/uploads\/2023\/03\/Worksheet-1-1-1-19.png 500w, https:\/\/9thclass.deltapublications.in\/wp-content\/uploads\/2023\/03\/Worksheet-1-1-1-19-300x300.png 300w, https:\/\/9thclass.deltapublications.in\/wp-content\/uploads\/2023\/03\/Worksheet-1-1-1-19-150x150.png 150w\" sizes=\"auto, (max-width: 500px) 100vw, 500px\" \/><\/a><\/figure>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Atomic Number And Mass Number Key notes : Definition of an Atom: Atomic Number (Z): Mass Number (A): Notation: where A is the mass number and Z is the atomic number. Isotopes: Importance of Atomic Number: Calculation Examples: Let&#8217;s practice!<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"class_list":["post-3659","page","type-page","status-publish","hentry","entry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/9thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/pages\/3659","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/9thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/9thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/9thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/9thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/comments?post=3659"}],"version-history":[{"count":19,"href":"https:\/\/9thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/pages\/3659\/revisions"}],"predecessor-version":[{"id":16351,"href":"https:\/\/9thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/pages\/3659\/revisions\/16351"}],"wp:attachment":[{"href":"https:\/\/9thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/media?parent=3659"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}