{"id":3513,"date":"2026-05-14T08:03:03","date_gmt":"2026-05-14T07:03:03","guid":{"rendered":"https:\/\/www.onlinelearningsystem.net\/xyz\/?page_id=3513"},"modified":"2026-06-28T05:54:36","modified_gmt":"2026-06-28T04:54:36","slug":"alkene","status":"publish","type":"page","link":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/organic-chemistry\/alkene\/","title":{"rendered":"Alkene"},"content":{"rendered":"\n<section class=\"ols-revision-page ols-alkene-page\">\n  <style>.ols-revision-page {\n      --navy: #1C244B;\n      --blue: #2563eb;\n      --soft-blue: #eef4ff;\n      --soft-red: #fff7f7;\n      --soft-purple: #f7f0ff;\n      --soft-green: #f0f7f1;\n      --soft-orange: #fff7ed;\n      --grey-text: #667085;\n      --body-text: #1f2937;\n      --border: rgba(28, 36, 75, 0.14);\n      --shadow: 0 18px 45px rgba(28, 36, 75, 0.10);\n      --inner-shadow: 0 10px 26px rgba(28, 36, 75, 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194, 0.34), 0 0 0 6px rgba(10, 102, 194, 0.10);\n    }\n\n    .ols-linkedin-pill:hover::before {\n      left: 120%;\n    }\n\n    .ols-linkedin-icon {\n      width: 18px;\n      height: 18px;\n      display: block;\n      flex-shrink: 0;\n      position: relative;\n      z-index: 1;\n    }\n\n    .ols-linkedin-pill span {\n      position: relative;\n      z-index: 1;\n      color: #ffffff !important;\n    }\n\n    @media (max-width: 640px) {\n      .ols-author {\n        align-items: flex-start;\n        padding: 22px 18px;\n        border-radius: 22px;\n      }\n\n      .ols-author-avatar-img {\n        width: 72px;\n        height: 72px;\n      }\n\n      .ols-author-title {\n        font-size: 24px;\n      }\n\n      .ols-author-description {\n        font-size: 15px;\n      }\n    }\n  <\/style>\n\n  <aside class=\"ols-sidebar\">\r\n  <div class=\"ols-sidebar-header\">\r\n    <h3>Revision Notes<\/h3>\r\n    <p>A Level Chemistry<\/p>\r\n  <\/div>\r\n\r\n  <div class=\"ols-topic-group\">\r\n    <h4>Topic 4 Organic Chemistry &amp; Alkanes<\/h4>\r\n\r\n    <ul class=\"ols-topic-list\">\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/hazard-and-risk\/\">Hazard &amp; Risk<\/a>\r\n      <\/li>\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/organic-chemistry\/\">Introduction To Organic Chemistry<\/a>\r\n\r\n        <ul class=\"ols-subtopic-list\">\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/organic-chemistry\/iupac-rules\/\">IUPAC Rules<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/organic-chemistry\/alkene\/\">Alkene<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/organic-chemistry\/alcohol\/\">Alcohol<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/organic-chemistry\/halogenoalkanes\/\">Halogenoalkanes<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/organic-chemistry\/aldehyde\/\">Aldehyde<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/organic-chemistry\/ketone\/\">Ketone<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/organic-chemistry\/carboxylic-acid\/\">Carboxylic Acid<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/organic-chemistry\/ester\/\">Ester<\/a>\r\n          <\/li>\r\n        <\/ul>\r\n      <\/li>\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/isomerism\/\">Isomerism<\/a>\r\n      <\/li>\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/crude-oil\/\">Alkanes from Crude Oil<\/a>\r\n\r\n        <ul class=\"ols-subtopic-list\">\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/crude-oil\/fractional-distillation\/\">Fractional Distillation<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/crude-oil\/cracking\/\">Cracking<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/crude-oil\/reforming\/\">Reforming<\/a>\r\n          <\/li>\r\n        <\/ul>\r\n      <\/li>\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/fuel\/\">Alkanes as Fuel<\/a>\r\n\r\n        <ul class=\"ols-subtopic-list\">\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/fuel\/combustion\/\">Combustion<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/fuel\/oxides-of-sulfur\/\">Oxides of Sulfur<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/fuel\/oxides-of-nitrogen\/\">Oxides of Nitrogen<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/fuel\/catalytic-converter\/\">Catalytic Converter<\/a>\r\n          <\/li>\r\n        <\/ul>\r\n      <\/li>\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/alternative-fuel\/\">Alternative Fuel<\/a>\r\n      <\/li>\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/reactions\/\">Reactions of Alkanes<\/a>\r\n\r\n        <ul class=\"ols-subtopic-list\">\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/reactions\/free-radical-substitution\/\">Free Radical Substitution<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/reactions\/initiation\/\">Initiation<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/reactions\/propagation\/\">Propagation<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/reactions\/termination\/\">Termination<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/reactions\/further-substitution\/\">Further Substitution<\/a>\r\n          <\/li>\r\n        <\/ul>\r\n      <\/li>\r\n    <\/ul>\r\n  <\/div>\r\n\r\n  <div class=\"ols-topic-group\">\r\n    <h4>Next Topics<\/h4>\r\n\r\n    <ul class=\"ols-topic-list\">\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-5-alkenes\/\">Alkenes<\/a>\r\n      <\/li>\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-6-energetics\/\">Energetics<\/a>\r\n      <\/li>\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-7-intermolecular-forces\/\">Intermolecular Forces<\/a>\r\n      <\/li>\r\n    <\/ul>\r\n  <\/div>\r\n<\/aside>\r\n\r\n<script>\r\n(function() {\r\n  function normalisePath(path) {\r\n    return String(path || '')\r\n      .split('?')[0]\r\n      .split('#')[0]\r\n      .replace(\/\\\/+$\/, '')\r\n      .toLowerCase();\r\n  }\r\n\r\n  function highlightActive() {\r\n    var sidebar = document.querySelector('.ols-sidebar');\r\n    if (!sidebar) return false;\r\n\r\n    var currentPath = normalisePath(window.location.pathname);\r\n    var links = sidebar.querySelectorAll('a[href]');\r\n    var matched = null;\r\n    var matchedLength = 0;\r\n\r\n    sidebar.querySelectorAll('.active, 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href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/\">Topic 4 Organic Chemistry &amp; Alkanes<\/a> \/\n        <span>Alkene<\/span>\n      <\/nav>\n\n      <header class=\"ols-title-card\">\n        <h1>Alkene<\/h1>\n        <p class=\"ols-page-intro\">A concise revision guide to alkene functional groups, carbon-carbon double bonds, the -ene suffix, E-Z naming, diene and triene suffixes, and functional group priority in IUPAC names.<\/p>\n\n        <div class=\"ols-badges\">\n          <div class=\"ols-badge\">Exam board: Edexcel International<\/div>\n          <div class=\"ols-badge\">Topic 4: Organic Chemistry &amp; Alkanes<\/div>\n          <div class=\"ols-badge\">Level: A Level Chemistry<\/div>\n        <\/div>\n\n        <div class=\"ols-author\">\n\n    <img decoding=\"async\"\n      class=\"ols-author-avatar-img\"\n      src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/Author-Profile.jpeg\"\n      alt=\"Dr. Mohammed Al-Fatah\"\n    >\n\n    <div class=\"ols-author-content\">\n\n      <h2 class=\"ols-author-title\">\n        Written by: Dr. Mohammed Al-Fatah\n      <\/h2>\n\n      <p class=\"ols-author-description\">\n        Chemistry specialist revision notes for A Level Chemistry.\n      <\/p>\n\n      <a class=\"ols-linkedin-pill\" href=\"https:\/\/www.linkedin.com\/in\/doctormohammedfatah\/\" target=\"_blank\" rel=\"noopener noreferrer\">\n        <svg class=\"ols-linkedin-icon\" viewBox=\"0 0 24 24\" fill=\"currentColor\" aria-hidden=\"true\">\n          <path d=\"M4.98 3.5C4.98 4.88 3.86 6 2.48 6S0 4.88 0 3.5 1.12 1 2.48 1s2.5 1.12 2.5 2.5zM.5 8h4V24h-4V8zm7 0h3.8v2.2h.1c.5-.9 1.8-2.2 3.9-2.2 4.2 0 5 2.8 5 6.4V24h-4v-7.6c0-1.8 0-4.2-2.6-4.2s-3 2-3 4v7.8h-4V8z\"\/>\n        <\/svg>\n        <span>View LinkedIn Profile<\/span>\n      <\/a>\n\n    <\/div>\n\n  <\/div>\n      <\/header>\n\n      <article class=\"ols-note-card soft\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">1<\/div>\n          <h2>What Is an Alkene?<\/h2>\n        <\/div>\n\n        <p>An <strong>alkene<\/strong> is an unsaturated hydrocarbon containing at least one <strong>carbon-carbon double bond<\/strong>, written as <strong>C=C<\/strong>. The double bond is always between two carbon atoms.<\/p>\n        <p>The C=C double bond is the <strong>functional group<\/strong> of alkenes. It is the part of the molecule responsible for the characteristic reactions of the homologous series.<\/p>\n        <p>For open-chain alkenes with one double bond, the general formula is <strong>C<sub>n<\/sub>H<sub>2n<\/sub><\/strong>.<\/p>\n\n        <div class=\"ols-key-box\">\n          <p><strong>Key idea:<\/strong> A molecule is not an alkene unless it contains a C=C double bond between two carbon atoms.<\/p>\n        <\/div>\n\n        <div class=\"ols-figure-card\">\n          <div class=\"ols-figure-image\">\n            <img decoding=\"async\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/alkene-functional-group.svg\" alt=\"General alkene functional group showing a carbon carbon double bond\">\n          <\/div>\n          <div class=\"ols-figure-caption\">\n            <p>The C=C double bond is shown explicitly because it is the functional group that defines the alkene homologous series.<\/p>\n          <\/div>\n        <\/div>\n      <\/article>\n\n      <article class=\"ols-note-card\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">2<\/div>\n          <h2>Naming Alkenes Using the -ene Suffix<\/h2>\n        <\/div>\n\n        <p>Alkenes are named using the suffix <strong>-ene<\/strong>. The parent carbon chain is chosen by identifying the longest chain that contains the C=C double bond.<\/p>\n        <p>When numbering the carbon chain, use the <strong>lower of the two possible numbers<\/strong> to show the position of the double bond. The number gives the first carbon of the C=C bond.<\/p>\n\n        <div class=\"ols-table-wrap\">\n          <table class=\"ols-table\">\n            <thead>\n              <tr>\n                <th>Homologous series<\/th>\n                <th>Functional group<\/th>\n                <th>Suffix<\/th>\n                <th>Example<\/th>\n              <\/tr>\n            <\/thead>\n            <tbody>\n              <tr>\n                <td data-label=\"Homologous series\">Alkenes<\/td>\n                <td data-label=\"Functional group\">C=C<\/td>\n                <td data-label=\"Suffix\">-ene<\/td>\n                <td data-label=\"Example\">propene<\/td>\n              <\/tr>\n            <\/tbody>\n          <\/table>\n        <\/div>\n\n        <div class=\"ols-figure-card\">\n          <div class=\"ols-figure-image\">\n            <img decoding=\"async\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/propene.svg\" alt=\"Propene skeletal structure\">\n          <\/div>\n          <div class=\"ols-figure-caption\">\n            <p>Propene contains three carbon atoms and one C=C double bond, so the parent name uses prop- and the alkene suffix -ene.<\/p>\n          <\/div>\n        <\/div>\n      <\/article>\n\n      <article class=\"ols-note-card purple\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">3<\/div>\n          <h2>E-Z Prefixes in Alkene Names<\/h2>\n        <\/div>\n\n        <p>Some alkene names begin with <strong>E<\/strong> or <strong>Z<\/strong>. These prefixes show the type of <strong>stereoisomer<\/strong> present.<\/p>\n        <p>This is needed because rotation around a C=C double bond is restricted. If the groups attached to the double bond are arranged differently in space, different stereoisomers can exist.<\/p>\n\n        <div class=\"ols-image-grid\">\n          <div class=\"ols-mini-figure\">\n            <div class=\"ols-mini-figure-image\">\n              <img decoding=\"async\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/z-but-2-ene.svg\" alt=\"Z-but-2-ene skeletal structure\">\n            <\/div>\n            <div class=\"ols-mini-figure-caption\">\n              <p>The Z prefix identifies the spatial arrangement of the groups around the C=C bond.<\/p>\n            <\/div>\n          <\/div>\n\n          <div class=\"ols-mini-figure\">\n            <div class=\"ols-mini-figure-image\">\n              <img decoding=\"async\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/e-but-2-enoic-acid.svg\" alt=\"E-but-2-enoic acid skeletal structure\">\n            <\/div>\n            <div class=\"ols-mini-figure-caption\">\n              <p>The E prefix can still be used when the molecule also contains a higher-priority functional group.<\/p>\n            <\/div>\n          <\/div>\n        <\/div>\n\n        <div class=\"ols-key-box\">\n          <p><strong>Exam focus:<\/strong> E and Z are stereochemical prefixes, not part of the carbon chain length. They describe the arrangement around the C=C double bond.<\/p>\n        <\/div>\n      <\/article>\n\n      <article class=\"ols-note-card orange\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">4<\/div>\n          <h2>More Than One Double Bond<\/h2>\n        <\/div>\n\n        <p>If a molecule contains more than one C=C double bond, the alkene suffix changes.<\/p>\n        <p>Two double bonds use the suffix <strong>-diene<\/strong>, while three double bonds use <strong>-triene<\/strong>. The positions of the double bonds are shown with numbers.<\/p>\n\n        <div class=\"ols-rule-list\">\n          <div class=\"ols-rule-item\">\n            <h3>One C=C bond<\/h3>\n            <p>Use <strong>-ene<\/strong>, such as but-2-ene.<\/p>\n          <\/div>\n          <div class=\"ols-rule-item\">\n            <h3>Two C=C bonds<\/h3>\n            <p>Use <strong>-diene<\/strong>, such as penta-1,3-diene.<\/p>\n          <\/div>\n          <div class=\"ols-rule-item\">\n            <h3>Three C=C bonds<\/h3>\n            <p>Use <strong>-triene<\/strong>, with numbers showing the positions of the three double bonds.<\/p>\n          <\/div>\n        <\/div>\n\n        <div class=\"ols-figure-card\">\n          <div class=\"ols-figure-image\">\n            <img decoding=\"async\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/penta-13-diene.svg\" alt=\"Penta-1,3-diene skeletal structure\">\n          <\/div>\n          <div class=\"ols-figure-caption\">\n            <p>The name penta-1,3-diene shows a five-carbon chain with double bonds beginning at carbon 1 and carbon 3.<\/p>\n          <\/div>\n        <\/div>\n      <\/article>\n\n      <article class=\"ols-note-card\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">5<\/div>\n          <h2>Alkenes with Other Functional Groups<\/h2>\n        <\/div>\n\n        <p>The <strong>-en<\/strong> part used for alkenes can appear before other functional group suffixes, such as <strong>-ol<\/strong> or <strong>-oic acid<\/strong>.<\/p>\n        <p>However, <strong>alcohol and carboxylic acid groups have higher priority than alkenes<\/strong>. This means they take precedence when numbering the carbon chain.<\/p>\n        <p>For example, in <strong>2-bromobut-3-en-1-ol<\/strong>, the alcohol group receives the lowest possible number because the OH group has higher priority than the C=C double bond.<\/p>\n\n        <div class=\"ols-image-grid\">\n          <div class=\"ols-mini-figure\">\n            <div class=\"ols-mini-figure-image\">\n              <img decoding=\"async\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/2-bromo-but-3-en-1-ol.svg\" alt=\"2-bromobut-3-en-1-ol skeletal structure\">\n            <\/div>\n            <div class=\"ols-mini-figure-caption\">\n              <p>The -en part shows the C=C bond, while -ol is the higher-priority suffix used for the alcohol group.<\/p>\n            <\/div>\n          <\/div>\n\n          <div class=\"ols-mini-figure\">\n            <div class=\"ols-mini-figure-image\">\n              <img decoding=\"async\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/e-but-2-enoic-acid.svg\" alt=\"E-but-2-enoic acid skeletal structure\">\n            <\/div>\n            <div class=\"ols-mini-figure-caption\">\n              <p>The carboxylic acid group takes priority, so the compound is named as an enoic acid rather than only as an alkene.<\/p>\n            <\/div>\n          <\/div>\n        <\/div>\n\n        <div class=\"ols-key-box\">\n          <p><strong>Remember:<\/strong> The C=C bond still needs to be included in the name, but higher-priority functional groups control the main suffix and numbering direction.<\/p>\n        <\/div>\n      <\/article>\n\n      <section class=\"ols-h5p-card\">\n        <h2>Check Your Understanding<\/h2>\n        <p>Use these short activities to check alkene naming, suffixes, stereochemical prefixes and functional group priority before moving on.<\/p>\n\n        <div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-68\" class=\"h5p-iframe\" data-content-id=\"68\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"T4.2.2 Drag: Alkene Key Concepts\"><\/iframe><\/div><\/div>\n        <div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-69\" class=\"h5p-iframe\" data-content-id=\"69\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"T4.2.3 MCQ: Alkene Functional Group\"><\/iframe><\/div><\/div>\n        <div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-70\" class=\"h5p-iframe\" data-content-id=\"70\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"T4.2.4 MCQ: Alkene Naming and Numbering\"><\/iframe><\/div><\/div>\n        <div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-71\" class=\"h5p-iframe\" data-content-id=\"71\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"T4.2.5 MCQ: Alkene Suffixes and Priority\"><\/iframe><\/div><\/div>\n      <\/section>\n\n      <section class=\"ols-course-cta-alkenes\" id=\"olsCourseCtaAlkenes001\">\n        <style>\n          .ols-course-cta-alkenes,\n          .ols-course-cta-alkenes * {\n            box-sizing: border-box;\n          }\n\n          .ols-course-cta-alkenes {\n            --navy: #1C244B;\n            --blue: #2563eb;\n            --body-text: #1f2937;\n            --grey-text: #667085;\n            --border: rgba(28, 36, 75, 0.14);\n            --shadow: 0 18px 45px rgba(28, 36, 75, 0.12);\n            --inner-shadow: 0 10px 26px rgba(28, 36, 75, 0.08);\n\n            width: 100%;\n            margin: 30px 0 24px;\n            font-family: Poppins, Arial, sans-serif;\n          }\n\n          .ols-course-cta-alkenes .ols-course-cta-card {\n            overflow: hidden;\n            border-radius: 30px;\n            border: 1px solid 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Topic 4A\/B Organic Chemistry and Alkanes course banner\">\n              <\/div>\n\n            <\/a>\n\n            <div class=\"ols-course-cta-content\">\n\n              <div class=\"ols-course-cta-header-row\">\n\n                <div class=\"ols-course-cta-kicker\">\n                  Complete Topic 4A\/B Organic Chemistry &amp; Alkanes Course\n                <\/div>\n\n                <a class=\"ols-course-button ols-course-button-top\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/product\/organic-chemistry-alkanes-topic-4ab-edexcel-international\/\">\n                  View Course\n                <\/a>\n\n              <\/div>\n\n              <h2>\n                Master Organic Chemistry and Alkanes for Edexcel International A Level Chemistry\n              <\/h2>\n\n            <\/div>\n\n          <\/div>\n\n          <div class=\"ols-course-cta-intro-stats\">\n\n            <p class=\"ols-course-cta-intro\">\n              Continue from these free revision notes into the full Topic 4A\/B Organic Chemistry and Alkanes course, with guided video teaching, diagnostic MCQ practice, teacher-marked short-answer questions and a specification assignment with a personalised progress report.\n            <\/p>\n\n            <div class=\"ols-course-cta-stats\">\n\n              <div class=\"ols-course-stat\">\n                <span>Guided learning<\/span>\n                <strong>16 hours<\/strong>\n              <\/div>\n\n              <div class=\"ols-course-stat\">\n                <span>Video lessons<\/span>\n                <strong>430 mins<\/strong>\n              <\/div>\n\n              <div class=\"ols-course-stat\">\n                <span>MCQ practice<\/span>\n                <strong>73 marks<\/strong>\n              <\/div>\n\n              <div class=\"ols-course-stat\">\n                <span>SAQ practice<\/span>\n                <strong>30 marks<\/strong>\n              <\/div>\n\n            <\/div>\n\n          <\/div>\n\n          <div class=\"ols-course-cta-features\">\n\n            <div class=\"ols-course-feature\">\n              <h3>Guided video teaching<\/h3>\n              <p>\n                Learn the chemistry and exam technique through structured video lessons with worked examples and walkthroughs.\n              <\/p>\n            <\/div>\n\n            <div class=\"ols-course-feature\">\n              <h3>Instant MCQ feedback<\/h3>\n              <p>\n                Auto-marked MCQ quizzes provide immediate diagnostic feedback for every answer choice.\n              <\/p>\n            <\/div>\n\n            <div class=\"ols-course-feature\">\n              <h3>Teacher-marked SAQs<\/h3>\n              <p>\n                Submit written exam responses and receive chemistry specialist feedback with improvement guidance.\n              <\/p>\n            <\/div>\n\n            <div class=\"ols-course-feature\">\n              <h3>Progress tracking<\/h3>\n              <p>\n                Identify 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src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/Virtual-Lesson.mp4\" muted=\"\" playsinline=\"\" preload=\"auto\">\n                  <\/video>\n                <\/div>\n              <\/div>\n            <\/section>\n          <\/div>\n        <\/section>\n\n        <section id=\"sceneMcq\" class=\"ols-scene\">\n          <div class=\"ols-mcq-stage\">\n            <div id=\"mcqIntroScreen\" class=\"ols-mcq-intro-screen\">\n              <div class=\"ols-mcq-intro-title-wrap\">\n                <h1 class=\"ols-mcq-intro-title\">\n                  <span id=\"mcqIntroTitleText\"><\/span><span id=\"mcqIntroTitleCursor\" class=\"ols-title-cursor\"><\/span>\n                <\/h1>\n              <\/div>\n            <\/div>\n\n            <div class=\"ols-mcq-scale-wrap\">\n              <main id=\"mcqScreen\" class=\"ols-mcq-screen\">\n                <section class=\"mcq-question-area\">\n                  <p class=\"mcq-question-lead\">Some ionic radii are shown.<\/p>\n\n                  <table class=\"mcq-ionic-table\">\n                    <thead>\n                      <tr>\n                        <th>Ion<\/th>\n                        <th>Ionic radius \/ nm<\/th>\n                      <\/tr>\n                    <\/thead>\n                    <tbody>\n                      <tr><td>Na<sup>+<\/sup><\/td><td>0.102<\/td><\/tr>\n                      <tr><td>K<sup>+<\/sup><\/td><td>0.138<\/td><\/tr>\n                      <tr><td>F<sup>\u2212<\/sup><\/td><td>0.133<\/td><\/tr>\n                      <tr><td>Cl<sup>\u2212<\/sup><\/td><td>0.180<\/td><\/tr>\n                    <\/tbody>\n                  <\/table>\n\n                  <p class=\"mcq-question-main\">Which compound has the strongest ionic bonding?<\/p>\n\n                  <div class=\"mcq-options-wrap\">\n                    <div id=\"mcqWrongOption\" class=\"mcq-option-row\">\n                      <span class=\"mcq-radio\"><\/span>\n                      <span class=\"mcq-radio-ripple\"><\/span>\n                      <span class=\"mcq-option-label\">sodium chloride<\/span>\n\n                      <span id=\"mcqSpecificFeedback\" class=\"mcq-specific-feedback\">\n                        <span id=\"mcqCrossIcon\" class=\"mcq-cross-icon\">\u00d7<\/span>\n                        <span class=\"mcq-specific-feedback-text\">\n                          <span id=\"mcqSpecificText\"><\/span><span id=\"mcqSpecificCursor\" class=\"cursor mcq-specific-cursor\" style=\"display:none;\"><\/span>\n                        <\/span>\n                      <\/span>\n                    <\/div>\n\n                    <div class=\"mcq-option-row\"><span class=\"mcq-radio\"><\/span><span class=\"mcq-radio-ripple\"><\/span><span class=\"mcq-option-label\">potassium chloride<\/span><\/div>\n                    <div class=\"mcq-option-row\"><span class=\"mcq-radio\"><\/span><span class=\"mcq-radio-ripple\"><\/span><span class=\"mcq-option-label\">sodium fluoride<\/span><\/div>\n                    <div class=\"mcq-option-row\"><span class=\"mcq-radio\"><\/span><span class=\"mcq-radio-ripple\"><\/span><span class=\"mcq-option-label\">potassium fluoride<\/span><\/div>\n                  <\/div>\n\n                  <button id=\"mcqSubmitButton\" class=\"mcq-submit-button\">Submit answer<\/button>\n                <\/section>\n\n                <section id=\"mcqGeneralFeedback\" class=\"mcq-general-feedback\">\n                  <span id=\"mcqGeneralText\"><\/span><span id=\"mcqGeneralCursor\" class=\"cursor mcq-general-cursor\" style=\"display:none;\"><\/span>\n                <\/section>\n              <\/main>\n            <\/div>\n          <\/div>\n        <\/section>\n\n        <section id=\"sceneSaq\" class=\"ols-scene\">\n          <div class=\"ols-saq-stage\">\n            <div id=\"saqIntro\" class=\"ols-saq-intro\">\n              <div class=\"ols-saq-intro-title-wrap\">\n                <h1 class=\"ols-saq-intro-title\">\n    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Melting temperature is a result of bonding strength, not the cause of it.\\n\\n\"+\n      \"In metallic bonding, positive metal ions are attracted to a sea of delocalised electrons. The strength of this attraction depends on the charge of the ions and the number of delocalised electrons.\\n\\n\"+\n      \"Magnesium forms Mg\u00b2\u207a ions and contributes two delocalised electrons per atom, whereas sodium forms Na\u207a ions and contributes only one electron. This results in a stronger electrostatic attraction in magnesium. Additionally, Mg\u00b2\u207a ions have a higher charge density than Na\u207a ions, further strengthening the metallic bonding.\\n\\n\"+\n      \"Next time, include:\\n\"+\n      \"\u2022 Ion charge: magnesium forms Mg\u00b2\u207a, sodium forms Na\u207a \u2713\\n\"+\n      \"\u2022 Delocalised electrons: magnesium provides more electrons to the sea \u2713\\n\"+\n      \"\u2022 Charge density: smaller, more highly charged ions create stronger attraction \u2713\\n\\n\"+\n      \"You were close. 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