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overflow: hidden; background: #ffffff; box-shadow: var(--inner-shadow); }\n      .ols-table td { border-bottom: 1px solid var(--border); padding: 14px 16px; overflow-wrap: anywhere; }\n      .ols-table td:last-child { border-bottom: none; }\n      .ols-table td::before { content: attr(data-label); display: block; margin-bottom: 6px; font-size: 13px; font-weight: 700; color: var(--blue); }\n      .ols-author { align-items: flex-start; padding: 22px 18px; border-radius: 22px; }\n      .ols-author-avatar-img { width: 72px; height: 72px; }\n      .ols-author-title { font-size: 24px; }\n      .ols-author-description { font-size: 15px; }\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 2 Bonding and Structure<\/h4>\r\n\r\n    <ul class=\"ols-topic-list\">\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/ionic-bonding\/\">Ionic Bonding<\/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\/topic-2-bonding-and-structure\/ionic-bonding\/nature-of-ionic-bonding\/\">Nature of Ionic Bonding<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/ionic-bonding\/polarisation-of-ions\/\">Polarisation of Ions<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/ionic-bonding\/physical-properties-of-ionic-compounds\/\">Physical Properties of Ionic Compounds<\/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\/topic-2-bonding-and-structure\/covalent-bonding\/\">Covalent Bonding<\/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\/topic-2-bonding-and-structure\/covalent-bonding\/nature-of-covalent-bonding\/\">Nature of Covalent Bonding<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/covalent-bonding\/dative-covalent-bonding\/\">Dative Covalent Bonding<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/covalent-bonding\/electronegativity\/\">Electronegativity<\/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\/topic-2-bonding-and-structure\/shapes-of-molecules\/\">Shapes of Molecules<\/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\/topic-2-bonding-and-structure\/shapes-of-molecules\/linear\/\">Linear<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/shapes-of-molecules\/trigonal-planar\/\">Trigonal Planar<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/shapes-of-molecules\/tetrahedral\/\">Tetrahedral<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/shapes-of-molecules\/trigonal-pyramidal\/\">Trigonal Pyramidal<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/shapes-of-molecules\/bent\/\">Bent<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/shapes-of-molecules\/trigonal-bipyramidal\/\">Trigonal Bipyramidal<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/shapes-of-molecules\/octahedral\/\">Octahedral<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/shapes-of-molecules\/square-planar\/\">Square Planar<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/shapes-of-molecules\/square-pyramidal\/\">Square Pyramidal<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/shapes-of-molecules\/distorted-t\/\">Distorted T<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/shapes-of-molecules\/seesaw\/\">SeeSaw<\/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\/topic-2-bonding-and-structure\/polar-molecules\/\">Polar Molecules<\/a>\r\n      <\/li>\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/metallic-bonding\/\">Metallic Bonding<\/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\/topic-2-bonding-and-structure\/metallic-bonding\/metallic-bonding-and-structure\/\">Metallic Bonding and Structure<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/metallic-bonding\/physical-properties-of-metals\/\">Physical Properties of Metals<\/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\/topic-2-bonding-and-structure\/intermolecular-forces\/\">Intermolecular Forces<\/a>\r\n      <\/li>\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/structure-types\/\">Structure Types<\/a>\r\n      <\/li>\r\n\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\/topic-3-redox-i\/\">Redox I<\/a>\r\n      <\/li>\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-4-inorganic-chemistry-and-the-periodic-table\/\">Inorganic Chemistry &amp; The Periodic Table<\/a>\r\n      <\/li>\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/\">Formulae, Equations &amp; Amounts<\/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, .active-main, .parent-active').forEach(function(item) {\r\n      item.classList.remove('active', 'active-main', 'parent-active');\r\n    });\r\n\r\n    sidebar.querySelectorAll('a[data-ols-disabled-parent=\"1\"], a[aria-current]').forEach(function(a) {\r\n      a.removeAttribute('aria-current');\r\n      a.removeAttribute('tabindex');\r\n      a.removeAttribute('data-ols-disabled-parent');\r\n    });\r\n\r\n    links.forEach(function(a) {\r\n      try {\r\n        var href = a.getAttribute('href');\r\n        if (!href || href === '#' || href.charAt(0) === '#') return;\r\n        var linkPath = normalisePath(new URL(href, window.location.origin).pathname);\r\n        if (!linkPath) return;\r\n        if (currentPath === linkPath || currentPath.indexOf(linkPath + '\/') === 0) {\r\n          if (linkPath.length > matchedLength) {\r\n            matched = a;\r\n            matchedLength = linkPath.length;\r\n          }\r\n        }\r\n      } catch(e) {}\r\n    });\r\n\r\n    if (matched) {\r\n      var matchedLi = matched.closest('li');\r\n      var parentSub = matched.closest('.ols-subtopic-list');\r\n\r\n      if (parentSub) {\r\n        if (matchedLi) {\r\n          matchedLi.classList.add('active');\r\n          matched.setAttribute('aria-current', 'page');\r\n        }\r\n        var parentLi = parentSub.closest('li');\r\n        if (parentLi) {\r\n          parentLi.classList.add('parent-active', 'active-main');\r\n          var parentLink = parentLi.querySelector(':scope > a');\r\n          if (parentLink) {\r\n            parentLink.setAttribute('aria-current', 'true');\r\n            parentLink.setAttribute('tabindex', '-1');\r\n            parentLink.setAttribute('data-ols-disabled-parent', '1');\r\n          }\r\n        }\r\n      } else {\r\n        if (matchedLi) {\r\n          matchedLi.classList.add('parent-active', 'active-main');\r\n          matched.setAttribute('aria-current', 'page');\r\n          matched.setAttribute('tabindex', '-1');\r\n          matched.setAttribute('data-ols-disabled-parent', '1');\r\n        }\r\n      }\r\n    }\r\n\r\n    return true;\r\n  }\r\n\r\n  if (!highlightActive()) {\r\n    document.addEventListener('DOMContentLoaded', highlightActive);\r\n  }\r\n})();\r\n<\/script>\n\n  <main class=\"ols-main\">\n      <nav class=\"ols-breadcrumbs\" aria-label=\"Breadcrumb\">\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/\">Revision Notes<\/a> \/\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/\">A Level Chemistry<\/a> \/\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/\">Edexcel<\/a> \/\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/\">Topic 2 Bonding and Structure<\/a> \/\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/shapes-of-molecules\/\">Shapes of Molecules<\/a> \/\n        <span>Linear<\/span>\n      <\/nav>\n\n      <header class=\"ols-title-card\">\n        <h1>Linear Molecular Shape<\/h1>\n        <p class=\"ols-page-intro\">A focused revision guide to the linear molecular shape, using BeCl<sub>2<\/sub> as the key example. This page explains why two bonding pairs and no lone pairs around a central atom give a 180\u00b0 bond angle.<\/p>\n\n        <div class=\"ols-badges\">\n          <div class=\"ols-badge\">Unit: Paper 1<\/div>\n          <div class=\"ols-badge\">Topic 2: Bonding and Structure<\/div>\n          <div class=\"ols-badge\">9CH0\/01<\/div>\n        <\/div>\n\n                <div class=\"ols-author\">\n\n    <img decoding=\"async\" class=\"ols-author-avatar-img\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/Author-Profile.jpeg\" alt=\"Dr. Mohammed Al-Fatah\">\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\"><\/path>\n        <\/svg>\n        View LinkedIn Profile\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>Why Electron Pairs Repel<\/h2>\n        <\/div>\n        <p>All electrons carry a <strong>negative charge<\/strong>. Electron pairs therefore repel one another and arrange themselves as far apart as possible around a central atom.<\/p>\n        <p>This is the basis of the electron-pair repulsion model used to explain molecular shapes. The shape depends on how many <strong>bonding pairs<\/strong> and <strong>lone pairs<\/strong> of electrons surround the central atom.<\/p>\n        <div class=\"ols-key-box\"><p><strong>Key idea:<\/strong> molecular shape is controlled by electron-pair repulsion. Electron pairs move to positions of minimum repulsion.<\/p><\/div>\n      <\/article>\n\n      <section id=\"ols-electron-circle-repulsion-card\" class=\"ols-electron-circle-wrap\">\n  <style>\n    #ols-electron-circle-repulsion-card {\n      --ols-navy: #1C244B;\n      --ols-red: #c81e1e;\n      --ols-gold: #c9973a;\n      --ols-soft-blue: #EEF4FF;\n      --ols-soft-bg: #f7f8fb;\n      --ols-border: rgba(28, 36, 75, 0.12);\n      --ols-shadow: 0 14px 38px rgba(28, 36, 75, 0.14);\n      font-family: Poppins, Arial, sans-serif;\n      width: 100%;\n      margin: 28px 0;\n      color: var(--ols-navy);\n    }\n\n    #ols-electron-circle-repulsion-card * {\n      box-sizing: border-box;\n    }\n\n    #ols-electron-circle-repulsion-card .ols-model-card {\n      width: 100%;\n      background: linear-gradient(180deg, #ffffff 0%, #f8fbff 100%);\n      border: 1px solid var(--ols-border);\n      border-radius: 28px;\n      box-shadow: var(--ols-shadow);\n      overflow: hidden;\n    }\n\n    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600;\n      z-index: 20;\n      pointer-events: none;\n    }\n\n    #ols-electron-circle-repulsion-card .ols-repel-flash {\n      position: absolute;\n      left: 50%;\n      top: 50%;\n      width: 86px;\n      height: 86px;\n      transform: translate(-50%, -50%) scale(0.6);\n      border-radius: 50%;\n      border: 2px solid rgba(200, 30, 30, 0.45);\n      opacity: 0;\n      pointer-events: none;\n      z-index: 3;\n    }\n\n    #ols-electron-circle-repulsion-card .ols-repel-flash.is-active {\n      animation: olsRepelPulse 650ms ease-out;\n    }\n\n    @keyframes olsRepelPulse {\n      0% {\n        opacity: 0.8;\n        transform: translate(-50%, -50%) scale(0.6);\n      }\n      100% {\n        opacity: 0;\n        transform: translate(-50%, -50%) scale(3.2);\n      }\n    }\n\n    #ols-electron-circle-repulsion-card .ols-controls {\n      display: flex;\n      flex-wrap: wrap;\n      gap: 10px;\n      justify-content: center;\n      align-items: center;\n      padding: 18px 28px 8px 28px;\n    }\n\n    #ols-electron-circle-repulsion-card .ols-btn {\n      border: 0;\n      border-radius: 999px;\n      padding: 11px 18px;\n      font-family: Poppins, Arial, sans-serif;\n      font-size: 14px;\n      font-weight: 700;\n      cursor: pointer;\n      color: #ffffff;\n      background: var(--ols-navy);\n      box-shadow: 0 8px 18px rgba(28, 36, 75, 0.18);\n      transition: transform 180ms ease, box-shadow 180ms ease, background 180ms ease;\n    }\n\n    #ols-electron-circle-repulsion-card .ols-btn:hover {\n      transform: translateY(-2px);\n      box-shadow: 0 12px 24px rgba(28, 36, 75, 0.22);\n    }\n\n    #ols-electron-circle-repulsion-card .ols-btn.secondary {\n      background: var(--ols-red);\n    }\n\n    #ols-electron-circle-repulsion-card .ols-explanation {\n      margin: 18px 28px 28px 28px;\n      padding: 22px 24px;\n      border-radius: 22px;\n      background: #ffffff;\n      border: 1px solid rgba(28, 36, 75, 0.1);\n      box-shadow: 0 10px 26px rgba(28, 36, 75, 0.08);\n    }\n\n    #ols-electron-circle-repulsion-card .ols-explanation h3 {\n      margin: 0 0 10px 0;\n      font-size: 22px;\n      font-weight: 700;\n      color: var(--ols-navy);\n    }\n\n    #ols-electron-circle-repulsion-card .ols-explanation p {\n      margin: 0;\n      font-size: 17px;\n      line-height: 1.75;\n      font-weight: 300;\n      color: rgba(28, 36, 75, 0.86);\n    }\n\n    #ols-electron-circle-repulsion-card .ols-key-point {\n      margin-top: 14px;\n      padding: 14px 16px;\n      border-radius: 16px;\n      background: rgba(238, 244, 255, 0.9);\n      border-left: 5px solid var(--ols-gold);\n      font-size: 16px;\n      line-height: 1.65;\n      color: rgba(28, 36, 75, 0.9);\n    }\n\n    @media (max-width: 700px) {\n      #ols-electron-circle-repulsion-card .ols-model-header {\n        padding: 22px 18px 10px 18px;\n      }\n\n      #ols-electron-circle-repulsion-card .ols-viewer-panel {\n        margin: 14px 16px 0 16px;\n        min-height: 440px;\n      }\n\n      #ols-electron-circle-repulsion-card .ols-electron {\n        width: 54px;\n        height: 54px;\n        font-size: 30px;\n      }\n\n      #ols-electron-circle-repulsion-card .ols-instruction-badge {\n        top: 14px;\n        right: 14px;\n        left: 14px;\n        max-width: none;\n        text-align: center;\n        font-size: 13px;\n      }\n\n      #ols-electron-circle-repulsion-card .ols-angle-label {\n        transform: translate(-50%, calc(-50% + 70px));\n        font-size: 13px;\n      }\n\n      #ols-electron-circle-repulsion-card .ols-explanation {\n        margin: 16px;\n        padding: 18px;\n      }\n\n      #ols-electron-circle-repulsion-card .ols-model-subtitle {\n        font-size: 16px;\n      }\n    }\n  <\/style>\n\n  <div class=\"ols-model-card\">\n    <div class=\"ols-model-header\">\n      <div class=\"ols-model-pill\">3D Model Concept Card<\/div>\n      <h2 class=\"ols-model-title\">Electron Domains Move as Far Apart as Possible<\/h2>\n      <p class=\"ols-model-subtitle\">\n        This model introduces the geometric idea behind molecular shapes. Two negatively charged electron domains repel each other, so the most stable arrangement places them opposite each other on a circle.\n      <\/p>\n    <\/div>\n\n    <div class=\"ols-viewer-panel\" id=\"olsElectronCirclePanel\">\n      <div class=\"ols-instruction-badge\">\n        Drag either electron around the circle, then release.\n      <\/div>\n\n      <div class=\"ols-stage\" id=\"olsElectronCircleStage\">\n        <div class=\"ols-circle\" id=\"olsElectronCirclePath\"><\/div>\n        <div class=\"ols-diameter-line\" id=\"olsElectronDiameterLine\"><\/div>\n        <div class=\"ols-centre-dot\"><\/div>\n        <div class=\"ols-angle-label\" id=\"olsElectronAngleLabel\">Separation: 180\u00b0<\/div>\n        <div class=\"ols-repel-flash\" id=\"olsElectronRepelFlash\"><\/div>\n\n        <div class=\"ols-electron\" id=\"olsElectronA\" aria-label=\"Negative electron domain one\">\n          \u2212\n          <span class=\"ols-electron-label\">electron domain<\/span>\n        <\/div>\n\n        <div class=\"ols-electron\" id=\"olsElectronB\" aria-label=\"Negative electron domain two\">\n          \u2212\n          <span class=\"ols-electron-label\">electron domain<\/span>\n        <\/div>\n      <\/div>\n    <\/div>\n\n    <div class=\"ols-controls\">\n      <button class=\"ols-btn\" type=\"button\" id=\"olsElectronResetBtn\">Reset to 180\u00b0<\/button>\n      <button class=\"ols-btn secondary\" type=\"button\" id=\"olsElectronDemoBtn\">Show repulsion<\/button>\n    <\/div>\n\n    <div class=\"ols-explanation\">\n      <h3>What the model shows<\/h3>\n      <p>\n        Electron domains are negatively charged, so they repel one another. With only two electron domains around a central atom, the lowest repulsion arrangement is a straight line, with the two domains separated by 180\u00b0.\n      <\/p>\n      <div class=\"ols-key-point\">\n        This is the first step towards understanding why molecules with two bonding pairs, such as CO<sub>2<\/sub>, have a linear shape.\n      <\/div>\n    <\/div>\n  <\/div>\n\n  <script src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/JS\/1_electron-domain-2d-circle.js\"><\/script>\n<\/section>\n\n      <article class=\"ols-note-card\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">2<\/div>\n          <h2>From Electron Domains to Molecular Shape<\/h2>\n        <\/div>\n        <p>A simple two-dimensional circle helps show why two electron domains become opposite each other. Real molecules, however, exist in three-dimensional space.<\/p>\n        <p>When electron domains are allowed to arrange themselves in three dimensions, they spread out around an imaginary sphere centred on the central atom. With only two electron domains, the furthest-apart arrangement is still opposite sides of the central atom.<\/p>\n        <div class=\"ols-definition-box\"><p><strong>Electron domain:<\/strong> a region of electron density around a central atom. A single bond, double bond, triple bond or lone pair each counts as one electron domain for shape prediction.<\/p><\/div>\n      <\/article>\n\n      <section id=\"ols-3d-electron-sphere-card\" class=\"ols-3d-electron-sphere-card\">\n  <style>\n    #ols-3d-electron-sphere-card {\n      --ols-navy: #1C244B;\n      --ols-gold: #c9973a;\n      --ols-red: #c81e1e;\n      --ols-blue: #1f7ae0;\n      --ols-soft-blue: #EEF4FF;\n      --ols-border: rgba(28, 36, 75, 0.14);\n      --ols-shadow: 0 14px 34px rgba(28, 36, 75, 0.12);\n      font-family: Poppins, Arial, sans-serif;\n      color: var(--ols-navy);\n      width: 100%;\n      margin: 28px auto;\n    }\n\n    #ols-3d-electron-sphere-card * {\n      box-sizing: border-box;\n    }\n\n    #ols-3d-electron-sphere-card .ols-model-card {\n      width: 100%;\n      background: linear-gradient(180deg, #ffffff 0%, #f8fbff 100%);\n      border: 1px solid var(--ols-border);\n      border-radius: 28px;\n      box-shadow: var(--ols-shadow);\n      overflow: hidden;\n    }\n\n    #ols-3d-electron-sphere-card .ols-model-header {\n      padding: 24px 26px 16px;\n      border-bottom: 1px solid rgba(28, 36, 75, 0.08);\n      background:\n        radial-gradient(circle at top left, rgba(201, 151, 58, 0.16), transparent 34%),\n        radial-gradient(circle at top right, rgba(31, 122, 224, 0.12), transparent 32%),\n        #ffffff;\n    }\n\n    #ols-3d-electron-sphere-card .ols-pill {\n      display: inline-flex;\n      align-items: center;\n      gap: 8px;\n      padding: 7px 12px;\n      border-radius: 999px;\n      background: rgba(31, 122, 224, 0.1);\n      color: var(--ols-blue);\n      border: 1px solid rgba(31, 122, 224, 0.18);\n      font-size: 13px;\n      font-weight: 600;\n      margin-bottom: 12px;\n    }\n\n    #ols-3d-electron-sphere-card .ols-model-title {\n      margin: 0;\n      font-size: clamp(26px, 3vw, 40px);\n      line-height: 1.12;\n      font-weight: 600;\n      color: var(--ols-navy);\n      letter-spacing: -0.03em;\n    }\n\n    #ols-3d-electron-sphere-card .ols-model-subtitle {\n      margin: 12px 0 0;\n      font-size: clamp(16px, 1.4vw, 22px);\n      line-height: 1.55;\n      font-weight: 300;\n      color: rgba(28, 36, 75, 0.82);\n      max-width: 980px;\n    }\n\n    #ols-3d-electron-sphere-card .ols-viewer-wrap {\n      position: relative;\n      width: 100%;\n      height: 560px;\n      background:\n        radial-gradient(circle at center, rgba(31, 122, 224, 0.06), transparent 38%),\n        linear-gradient(180deg, #ffffff 0%, #f7f9fc 100%);\n      overflow: hidden;\n    }\n\n    #ols-3d-electron-sphere-card #olsElectronSphereViewer {\n      width: 100%;\n      height: 100%;\n      display: block;\n    }\n\n    #ols-3d-electron-sphere-card .ols-viewer-badge {\n      position: absolute;\n      top: 16px;\n      right: 16px;\n      background: rgba(255, 255, 255, 0.92);\n      color: var(--ols-navy);\n      padding: 8px 12px;\n      border-radius: 12px;\n      font-size: 13px;\n      font-weight: 600;\n      box-shadow: 0 6px 18px rgba(28, 36, 75, 0.14);\n      border: 1px solid rgba(28, 36, 75, 0.08);\n      pointer-events: none;\n      z-index: 4;\n    }\n\n    #ols-3d-electron-sphere-card .ols-angle-badge {\n      position: absolute;\n      left: 16px;\n      bottom: 16px;\n      background: rgba(255, 255, 255, 0.94);\n      color: var(--ols-navy);\n      padding: 8px 12px;\n      border-radius: 999px;\n      font-size: 13px;\n      font-weight: 700;\n      box-shadow: 0 6px 18px rgba(28, 36, 75, 0.14);\n      border: 1px solid rgba(28, 36, 75, 0.08);\n      pointer-events: none;\n      z-index: 4;\n    }\n\n    #ols-3d-electron-sphere-card .ols-controls {\n      display: flex;\n      flex-wrap: wrap;\n      gap: 10px;\n      padding: 16px 18px;\n      background: #ffffff;\n      border-top: 1px solid rgba(28, 36, 75, 0.08);\n    }\n\n    #ols-3d-electron-sphere-card .ols-btn {\n      appearance: none;\n      border: 1px solid rgba(28, 36, 75, 0.14);\n      background: #ffffff;\n      color: var(--ols-navy);\n      border-radius: 999px;\n      padding: 10px 15px;\n      font-family: Poppins, Arial, sans-serif;\n      font-size: 14px;\n      font-weight: 600;\n      cursor: pointer;\n      transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease, color 0.2s ease;\n    }\n\n    #ols-3d-electron-sphere-card .ols-btn:hover {\n      transform: translateY(-2px);\n      box-shadow: 0 8px 20px rgba(28, 36, 75, 0.12);\n    }\n\n    #ols-3d-electron-sphere-card .ols-btn.is-active {\n      background: var(--ols-navy);\n      color: #ffffff;\n      border-color: var(--ols-navy);\n    }\n\n    #ols-3d-electron-sphere-card .ols-btn.ols-red {\n      background: var(--ols-red);\n      color: #ffffff;\n      border-color: var(--ols-red);\n    }\n\n    #ols-3d-electron-sphere-card .ols-explanation {\n      padding: 22px 26px 26px;\n      background: #ffffff;\n      border-top: 1px solid rgba(28, 36, 75, 0.08);\n    }\n\n    #ols-3d-electron-sphere-card .ols-key-message {\n      margin: 0;\n      padding: 16px 18px;\n      border-radius: 18px;\n      background: var(--ols-soft-blue);\n      border: 1px solid rgba(31, 122, 224, 0.14);\n      font-size: 16px;\n      line-height: 1.65;\n      font-weight: 300;\n      color: rgba(28, 36, 75, 0.88);\n    }\n\n    #ols-3d-electron-sphere-card .ols-key-message strong {\n      font-weight: 700;\n      color: var(--ols-navy);\n    }\n\n    #ols-3d-electron-sphere-card .ols-explanation-grid {\n      display: grid;\n      grid-template-columns: repeat(3, minmax(0, 1fr));\n      gap: 14px;\n      margin-top: 16px;\n    }\n\n    #ols-3d-electron-sphere-card .ols-info-box {\n      border-radius: 18px;\n      padding: 16px;\n      background: #f8fbff;\n      border: 1px solid rgba(28, 36, 75, 0.1);\n    }\n\n    #ols-3d-electron-sphere-card .ols-info-box strong {\n      display: block;\n      font-size: 15px;\n      margin-bottom: 6px;\n      color: var(--ols-navy);\n    }\n\n    #ols-3d-electron-sphere-card .ols-info-box span {\n      display: block;\n      font-size: 14px;\n      line-height: 1.55;\n      font-weight: 300;\n      color: rgba(28, 36, 75, 0.8);\n    }\n\n    @media (max-width: 820px) {\n      #ols-3d-electron-sphere-card .ols-viewer-wrap {\n        height: 470px;\n      }\n\n      #ols-3d-electron-sphere-card .ols-explanation-grid {\n        grid-template-columns: 1fr;\n      }\n\n      #ols-3d-electron-sphere-card .ols-viewer-badge {\n        top: 12px;\n        right: 12px;\n        font-size: 12px;\n      }\n    }\n\n    @media (max-width: 520px) {\n      #ols-3d-electron-sphere-card .ols-model-header,\n      #ols-3d-electron-sphere-card .ols-explanation {\n        padding-left: 18px;\n        padding-right: 18px;\n      }\n\n      #ols-3d-electron-sphere-card .ols-viewer-wrap {\n        height: 420px;\n      }\n\n      #ols-3d-electron-sphere-card .ols-controls {\n        padding: 14px;\n      }\n\n      #ols-3d-electron-sphere-card .ols-btn {\n        width: 100%;\n      }\n\n      #ols-3d-electron-sphere-card .ols-viewer-badge {\n        left: 12px;\n        right: 12px;\n        text-align: center;\n      }\n    }\n  <\/style>\n\n  <div class=\"ols-model-card\">\n    <div class=\"ols-model-header\">\n      <div class=\"ols-pill\">3D electron-domain model<\/div>\n      <h2 class=\"ols-model-title\">From a 2D Circle to a 3D Sphere<\/h2>\n      <p class=\"ols-model-subtitle\">\n        Real atoms are three-dimensional. Electron domains are not restricted to a flat circle, so they can spread out in the x, y and z directions. With two electron domains, the maximum separation is still 180\u00b0.\n      <\/p>\n    <\/div>\n\n    <div class=\"ols-viewer-wrap\">\n      <div id=\"olsElectronSphereViewer\"><\/div>\n      <div class=\"ols-viewer-badge\">Drag the model to rotate \u2022 Drag an electron to move it on the sphere<\/div>\n      <div class=\"ols-angle-badge\" id=\"olsElectronSphereAngleBadge\">Separation: 180\u00b0<\/div>\n    <\/div>\n\n    <div class=\"ols-controls\">\n      <button type=\"button\" class=\"ols-btn is-active\" id=\"olsElectronSphereRotateBtn\">Pause rotation<\/button>\n      <button type=\"button\" class=\"ols-btn ols-red\" id=\"olsElectronSphereDemoBtn\">Show 3D repulsion<\/button>\n      <button type=\"button\" class=\"ols-btn\" id=\"olsElectronSphereResetBtn\">Reset view<\/button>\n    <\/div>\n\n    <div class=\"ols-explanation\">\n      <p class=\"ols-key-message\">\n        <strong>Key idea:<\/strong> once electron domains are allowed to move in three dimensions, they spread out on the surface of an imaginary sphere around the central atom. For two electron domains, the lowest-repulsion arrangement places them directly opposite each other, giving a <strong>180\u00b0 bond angle<\/strong>.\n      <\/p>\n\n      <div class=\"ols-explanation-grid\">\n        <div class=\"ols-info-box\">\n          <strong>2D circle<\/strong>\n          <span>The first model only allowed movement around a flat circle, using the x and y directions.<\/span>\n        <\/div>\n\n        <div class=\"ols-info-box\">\n          <strong>3D sphere<\/strong>\n          <span>This model adds depth, so the electron domains can also move in the z direction.<\/span>\n        <\/div>\n\n        <div class=\"ols-info-box\">\n          <strong>Final arrangement<\/strong>\n          <span>Two electron domains still become linear because opposite sides of the sphere are furthest apart.<\/span>\n        <\/div>\n      <\/div>\n    <\/div>\n  <\/div>\n\n  <script src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/JS\/2_from-2d-to-3d-sphere.js\"><\/script>\n<\/section>\n\n      <article class=\"ols-note-card purple\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">3<\/div>\n          <h2>The Linear Shape<\/h2>\n        <\/div>\n        <p>A molecule is <strong>linear<\/strong> when there are <strong>two bonding pairs<\/strong> and <strong>no lone pairs<\/strong> around the central atom.<\/p>\n        <p>The two bonding pairs repel equally. The lowest-repulsion arrangement places the two bonds in opposite directions, giving a bond angle of <strong>180\u00b0<\/strong>.<\/p>\n\n        <div class=\"ols-table-wrap\">\n          <table class=\"ols-table\">\n            <thead>\n              <tr>\n                <th>Shape<\/th>\n                <th>Bonding pairs<\/th>\n                <th>Lone pairs<\/th>\n                <th>Bond angle<\/th>\n                <th>Examples<\/th>\n              <\/tr>\n            <\/thead>\n            <tbody>\n              <tr>\n                <td data-label=\"Shape\"><strong>Linear<\/strong><\/td>\n                <td data-label=\"Bonding pairs\">2<\/td>\n                <td data-label=\"Lone pairs\">0<\/td>\n                <td data-label=\"Bond angle\"><strong>180\u00b0<\/strong><\/td>\n                <td data-label=\"Examples\">CO<sub>2<\/sub>, CS<sub>2<\/sub>, HCN, BeF<sub>2<\/sub>, BeCl<sub>2<\/sub><\/td>\n              <\/tr>\n            <\/tbody>\n          <\/table>\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>Linear Shape in BeCl<sub>2<\/sub><\/h2>\n        <\/div>\n        <p>In BeCl<sub>2<\/sub>, beryllium is the central atom and chlorine atoms are bonded on either side. The central beryllium atom has <strong>two bonding pairs<\/strong> and <strong>no lone pairs<\/strong> in the shape model.<\/p>\n        <p>The two Be-Cl bonding pairs repel equally and move as far apart as possible. This gives a <strong>linear molecule<\/strong> with a <strong>Cl-Be-Cl bond angle of 180\u00b0<\/strong>.<\/p>\n        <div class=\"ols-key-box\"><p><strong>Exam sentence:<\/strong> BeCl<sub>2<\/sub> has two bonding pairs and no lone pairs around Be. The bonding pairs repel equally and move as far apart as possible, so the molecule is linear with a 180\u00b0 bond angle.<\/p><\/div>\n      <\/article>\n\n      <div class=\"ols-zoom-card compact\">\n        <div class=\"ols-zoom-card-image\">\n          <img decoding=\"async\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/BeCl2.png\" alt=\"Linear BeCl2 molecule showing chlorine atoms bonded to central beryllium at 180 degrees\" class=\"ols-zoomable-img ols-lightbox-target\" draggable=\"false\">\n        <\/div>\n        <div class=\"ols-zoom-card-caption\">\n          <p>BeCl<sub>2<\/sub> is linear because the two bonding pairs around the central Be atom repel equally and sit opposite one another.<\/p>\n        <\/div>\n      <\/div>\n\n      <section id=\"ols-becl2-linear-card\" class=\"ols-becl2-linear-card\">\n  <style>\n    #ols-becl2-linear-card {\n      --ols-navy: #1C244B;\n      --ols-gold: #c9973a;\n      --ols-red: #c81e1e;\n      --ols-green: #31a36a;\n      --ols-blue: #1f7ae0;\n      --ols-soft-blue: #EEF4FF;\n      --ols-border: rgba(28, 36, 75, 0.14);\n      --ols-shadow: 0 14px 34px rgba(28, 36, 75, 0.12);\n      font-family: Poppins, Arial, sans-serif;\n      color: var(--ols-navy);\n      width: 100%;\n      margin: 28px auto;\n    }\n\n    #ols-becl2-linear-card * {\n      box-sizing: border-box;\n    }\n\n    #ols-becl2-linear-card .ols-model-card {\n      width: 100%;\n      background: linear-gradient(180deg, #ffffff 0%, #f8fbff 100%);\n      border: 1px solid var(--ols-border);\n      border-radius: 28px;\n      box-shadow: var(--ols-shadow);\n      overflow: hidden;\n    }\n\n    #ols-becl2-linear-card .ols-model-header {\n      padding: 24px 26px 16px;\n      border-bottom: 1px solid rgba(28, 36, 75, 0.08);\n      background:\n        radial-gradient(circle at top left, rgba(201, 151, 58, 0.16), transparent 34%),\n        radial-gradient(circle at top right, rgba(31, 122, 224, 0.12), transparent 32%),\n        #ffffff;\n    }\n\n    #ols-becl2-linear-card .ols-pill {\n      display: inline-flex;\n      align-items: center;\n      gap: 8px;\n      padding: 7px 12px;\n      border-radius: 999px;\n      background: rgba(31, 122, 224, 0.1);\n      color: var(--ols-blue);\n      border: 1px solid rgba(31, 122, 224, 0.18);\n      font-size: 13px;\n      font-weight: 600;\n      margin-bottom: 12px;\n    }\n\n    #ols-becl2-linear-card .ols-model-title {\n      margin: 0;\n      font-size: clamp(26px, 3vw, 40px);\n      line-height: 1.12;\n      font-weight: 600;\n      color: var(--ols-navy);\n      letter-spacing: -0.03em;\n    }\n\n    #ols-becl2-linear-card .ols-model-subtitle {\n      margin: 12px 0 0;\n      font-size: clamp(16px, 1.4vw, 22px);\n      line-height: 1.55;\n      font-weight: 300;\n      color: rgba(28, 36, 75, 0.82);\n      max-width: 980px;\n    }\n\n    #ols-becl2-linear-card .ols-viewer-wrap {\n      position: relative;\n      width: 100%;\n      height: 580px;\n      background:\n        radial-gradient(circle at center, rgba(31, 122, 224, 0.06), transparent 38%),\n        linear-gradient(180deg, #ffffff 0%, #f7f9fc 100%);\n      overflow: hidden;\n    }\n\n    #ols-becl2-linear-card #olsBeCl2Viewer {\n      width: 100%;\n      height: 100%;\n      display: block;\n    }\n\n    #ols-becl2-linear-card .ols-viewer-badge {\n      position: absolute;\n      top: 16px;\n      right: 16px;\n      background: rgba(255, 255, 255, 0.92);\n      color: var(--ols-navy);\n      padding: 8px 12px;\n      border-radius: 12px;\n      font-size: 13px;\n      font-weight: 600;\n      box-shadow: 0 6px 18px rgba(28, 36, 75, 0.14);\n      border: 1px solid rgba(28, 36, 75, 0.08);\n      pointer-events: none;\n      z-index: 4;\n    }\n\n    #ols-becl2-linear-card .ols-angle-badge {\n      position: absolute;\n      left: 16px;\n      bottom: 16px;\n      background: rgba(255, 255, 255, 0.94);\n      color: var(--ols-navy);\n      padding: 8px 12px;\n      border-radius: 999px;\n      font-size: 13px;\n      font-weight: 700;\n      box-shadow: 0 6px 18px rgba(28, 36, 75, 0.14);\n      border: 1px solid rgba(28, 36, 75, 0.08);\n      pointer-events: none;\n      z-index: 4;\n    }\n\n    #ols-becl2-linear-card .ols-controls {\n      display: flex;\n      flex-wrap: wrap;\n      gap: 10px;\n      padding: 16px 18px;\n      background: #ffffff;\n      border-top: 1px solid rgba(28, 36, 75, 0.08);\n    }\n\n    #ols-becl2-linear-card .ols-btn {\n      appearance: none;\n      border: 1px solid rgba(28, 36, 75, 0.14);\n      background: #ffffff;\n      color: var(--ols-navy);\n      border-radius: 999px;\n      padding: 10px 15px;\n      font-family: Poppins, Arial, sans-serif;\n      font-size: 14px;\n      font-weight: 600;\n      cursor: pointer;\n      transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease, color 0.2s ease;\n    }\n\n    #ols-becl2-linear-card .ols-btn:hover {\n      transform: translateY(-2px);\n      box-shadow: 0 8px 20px rgba(28, 36, 75, 0.12);\n    }\n\n    #ols-becl2-linear-card .ols-btn.is-active {\n      background: var(--ols-navy);\n      color: #ffffff;\n      border-color: var(--ols-navy);\n    }\n\n    #ols-becl2-linear-card .ols-btn.ols-red {\n      background: var(--ols-red);\n      color: #ffffff;\n      border-color: var(--ols-red);\n    }\n\n    #ols-becl2-linear-card .ols-explanation {\n      padding: 22px 26px 26px;\n      background: #ffffff;\n      border-top: 1px solid rgba(28, 36, 75, 0.08);\n    }\n\n    #ols-becl2-linear-card .ols-key-message {\n      margin: 0;\n      padding: 16px 18px;\n      border-radius: 18px;\n      background: var(--ols-soft-blue);\n      border: 1px solid rgba(31, 122, 224, 0.14);\n      font-size: 16px;\n      line-height: 1.65;\n      font-weight: 300;\n      color: rgba(28, 36, 75, 0.88);\n    }\n\n    #ols-becl2-linear-card .ols-key-message strong {\n      font-weight: 700;\n      color: var(--ols-navy);\n    }\n\n    #ols-becl2-linear-card .ols-explanation-grid {\n      display: grid;\n      grid-template-columns: repeat(3, minmax(0, 1fr));\n      gap: 14px;\n      margin-top: 16px;\n    }\n\n    #ols-becl2-linear-card .ols-info-box {\n      border-radius: 18px;\n      padding: 16px;\n      background: #f8fbff;\n      border: 1px solid rgba(28, 36, 75, 0.1);\n    }\n\n    #ols-becl2-linear-card .ols-info-box strong {\n      display: block;\n      font-size: 15px;\n      margin-bottom: 6px;\n      color: var(--ols-navy);\n    }\n\n    #ols-becl2-linear-card .ols-info-box span {\n      display: block;\n      font-size: 14px;\n      line-height: 1.55;\n      font-weight: 300;\n      color: rgba(28, 36, 75, 0.8);\n    }\n\n    @media (max-width: 820px) {\n      #ols-becl2-linear-card .ols-viewer-wrap {\n        height: 490px;\n      }\n\n      #ols-becl2-linear-card .ols-explanation-grid {\n        grid-template-columns: 1fr;\n      }\n\n      #ols-becl2-linear-card .ols-viewer-badge {\n        top: 12px;\n        right: 12px;\n        font-size: 12px;\n      }\n    }\n\n    @media (max-width: 520px) {\n      #ols-becl2-linear-card .ols-model-header,\n      #ols-becl2-linear-card .ols-explanation {\n        padding-left: 18px;\n        padding-right: 18px;\n      }\n\n      #ols-becl2-linear-card .ols-viewer-wrap {\n        height: 430px;\n      }\n\n      #ols-becl2-linear-card .ols-controls {\n        padding: 14px;\n      }\n\n      #ols-becl2-linear-card .ols-btn {\n        width: 100%;\n      }\n\n      #ols-becl2-linear-card .ols-viewer-badge {\n        left: 12px;\n        right: 12px;\n        text-align: center;\n      }\n    }\n  <\/style>\n\n  <div class=\"ols-model-card\">\n    <div class=\"ols-model-header\">\n      <div class=\"ols-pill\">3D molecule shape model<\/div>\n      <h2 class=\"ols-model-title\">Linear Shape of BeCl<sub>2<\/sub><\/h2>\n      <p class=\"ols-model-subtitle\">\n        The centre of the sphere represents the nucleus of the central atom, beryllium. The two electron domains are now shown as two covalent bonds to chlorine atoms. Each bonding pair is negatively charged, so the bonds repel each other and spread out to 180\u00b0, giving a linear molecule.\n      <\/p>\n    <\/div>\n\n    <div class=\"ols-viewer-wrap\">\n      <div id=\"olsBeCl2Viewer\"><\/div>\n      <div class=\"ols-viewer-badge\">Drag the model to rotate \u2022 Drag either red bonding pair to move the bond<\/div>\n      <div class=\"ols-angle-badge\" id=\"olsBeCl2AngleBadge\">Bond angle: 180\u00b0<\/div>\n    <\/div>\n\n    <div class=\"ols-controls\">\n      <button type=\"button\" class=\"ols-btn is-active\" id=\"olsBeCl2RotateBtn\">Pause rotation<\/button>\n      <button type=\"button\" class=\"ols-btn ols-red\" id=\"olsBeCl2DemoBtn\">Show repulsion<\/button>\n      <button type=\"button\" class=\"ols-btn\" id=\"olsBeCl2ResetBtn\">Reset view<\/button>\n    <\/div>\n\n    <div class=\"ols-explanation\">\n      <p class=\"ols-key-message\">\n        <strong>Key idea:<\/strong> the two Be-Cl bonding pairs repel one another because they contain negatively charged electrons. To minimise repulsion, the bonds move as far apart as possible, producing a <strong>180\u00b0 bond angle<\/strong> and a <strong>linear shape<\/strong>.\n      <\/p>\n\n      <div class=\"ols-explanation-grid\">\n        <div class=\"ols-info-box\">\n          <strong>Central atom<\/strong>\n          <span>Beryllium is the central atom, shown at the centre of the model.<\/span>\n        <\/div>\n\n        <div class=\"ols-info-box\">\n          <strong>Bonding pairs<\/strong>\n          <span>Each covalent bond contains a shared pair of electrons shown in red halfway along the bond.<\/span>\n        <\/div>\n\n        <div class=\"ols-info-box\">\n          <strong>Shape outcome<\/strong>\n          <span>Because there are two bonding pairs and no lone pairs around Be, BeCl<sub>2<\/sub> is linear.<\/span>\n        <\/div>\n      <\/div>\n    <\/div>\n  <\/div>\n\n  <script src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/JS\/3_linear-shape-becl2.js\"><\/script>\n<\/section>\n\n      <article class=\"ols-note-card\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">5<\/div>\n          <h2>How to Explain Shape in an Exam<\/h2>\n        <\/div>\n        <p>Shape explanations need a clear sequence. State the number of electron pairs first, then explain repulsion, then give the shape and bond angle.<\/p>\n        <div class=\"ols-rule-list\">\n          <div class=\"ols-rule-item\"><h3>1. Count electron pairs<\/h3><p>State the number of bonding pairs and lone pairs around the central atom.<\/p><\/div>\n          <div class=\"ols-rule-item\"><h3>2. Use repulsion language<\/h3><p>State that electron pairs repel and arrange themselves as far apart as possible.<\/p><\/div>\n          <div class=\"ols-rule-item\"><h3>3. Compare pair types where needed<\/h3><p>If there are no lone pairs, state that the bonding pairs repel equally. If there are lone pairs, state that lone pairs repel more strongly than bonding pairs.<\/p><\/div>\n          <div class=\"ols-rule-item\"><h3>4. Give the final shape and angle<\/h3><p>For BeCl<sub>2<\/sub>, the final answer is linear, 180\u00b0.<\/p><\/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\">6<\/div>\n          <h2>BeCl<sub>2<\/sub> Exam Answer Model<\/h2>\n        <\/div>\n        <p>Use the exam-answer structure from Part 5, then change only the molecule-specific information. The black wording is the reusable sentence frame. The coloured wording is the part that changes for each molecule.<\/p>\n\n        <div class=\"ols-rule-list\">\n          <div class=\"ols-rule-item\">\n            <h3>Model answer for BeCl<sub>2<\/sub><\/h3>\n            <p>There are <span style=\"color:#2563eb;font-weight:800;\">two bonding pairs<\/span> and <span style=\"color:#c81e1e;font-weight:800;\">no lone pairs<\/span> around the central <span style=\"color:#c9973a;font-weight:800;\">beryllium atom<\/span>.<\/p>\n            <p>Electron pairs repel each other and arrange themselves as far apart as possible to minimise repulsion.<\/p>\n            <p>Because there are <span style=\"color:#c81e1e;font-weight:800;\">no lone pairs<\/span>, the <span style=\"color:#2563eb;font-weight:800;\">two bonding pairs<\/span> repel equally.<\/p>\n            <p>The molecule is therefore <span style=\"color:#31a36a;font-weight:800;\">linear<\/span> with a bond angle of <span style=\"color:#31a36a;font-weight:800;\">180\u00b0<\/span>.<\/p>\n          <\/div>\n\n          <div class=\"ols-rule-item\">\n            <h3>Reusable sentence frame<\/h3>\n            <p>There are <span style=\"color:#2563eb;font-weight:800;\">[number of bonding pairs]<\/span> and <span style=\"color:#c81e1e;font-weight:800;\">[number of lone pairs]<\/span> around the central <span style=\"color:#c9973a;font-weight:800;\">[central atom]<\/span>.<\/p>\n            <p>Electron pairs repel each other and arrange themselves as far apart as possible to minimise repulsion.<\/p>\n            <p>If there are <span style=\"color:#c81e1e;font-weight:800;\">[no lone pairs]<\/span>, the bonding pairs repel equally. If there are lone pairs, the lone pairs repel more strongly than bonding pairs.<\/p>\n            <p>The molecule is therefore <span style=\"color:#31a36a;font-weight:800;\">[shape]<\/span> with a bond angle of <span style=\"color:#31a36a;font-weight:800;\">[bond angle]<\/span>.<\/p>\n          <\/div>\n\n          <div class=\"ols-rule-item\">\n            <h3>Colour key<\/h3>\n            <p><span style=\"color:#2563eb;font-weight:800;\">Blue<\/span> = bonding-pair information. <span style=\"color:#c81e1e;font-weight:800;\">Red<\/span> = lone-pair information. <span style=\"color:#c9973a;font-weight:800;\">Gold<\/span> = central atom. <span style=\"color:#31a36a;font-weight:800;\">Green<\/span> = final shape and bond angle.<\/p>\n          <\/div>\n        <\/div>\n      <\/article>\n\n      <article class=\"ols-note-card soft\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">7<\/div>\n          <h2>Common Exam Points<\/h2>\n        <\/div>\n        <p>Linear shape questions are usually straightforward, but marks are often lost when students describe the atoms moving apart instead of the electron pairs repelling.<\/p>\n        <div class=\"ols-rule-list\">\n          <div class=\"ols-rule-item\"><h3>Focus on electron pairs<\/h3><p>The cause of the shape is repulsion between regions of electron density, not a simple repulsion between atoms.<\/p><\/div>\n          <div class=\"ols-rule-item\"><h3>State no lone pairs clearly<\/h3><p>For BeCl<sub>2<\/sub>, the central Be atom has two bonding pairs and no lone pairs in the molecular shape model.<\/p><\/div>\n          <div class=\"ols-rule-item\"><h3>Use the exact angle<\/h3><p>The bond angle in a linear molecule is 180\u00b0. Do not write approximately 180\u00b0 unless the question specifically allows approximation.<\/p><\/div>\n          <div class=\"ols-rule-item\"><h3>Do not confuse linear with bent<\/h3><p>A bent molecule has lone pairs on the central atom. A linear molecule with two bonding regions and no lone pairs has a 180\u00b0 angle.<\/p><\/div>\n        <\/div>\n      <\/article>\n\n<section id=\"ols-xef2-linear-lone-pair-card\" class=\"ols-xef2-linear-lone-pair-card\">\n  <style>\n    #ols-xef2-linear-lone-pair-card {\n      --ols-navy: #1C244B;\n      --ols-gold: #c9973a;\n      --ols-red: #c81e1e;\n      --ols-green: #31a36a;\n      --ols-blue: #1f7ae0;\n      --ols-soft-blue: #EEF4FF;\n      --ols-border: rgba(28, 36, 75, 0.14);\n      --ols-shadow: 0 14px 34px rgba(28, 36, 75, 0.12);\n      font-family: Poppins, Arial, sans-serif;\n      color: var(--ols-navy);\n      width: 100%;\n      margin: 28px auto;\n    }\n\n    #ols-xef2-linear-lone-pair-card * {\n      box-sizing: border-box;\n    }\n\n    #ols-xef2-linear-lone-pair-card .ols-model-card {\n      width: 100%;\n      background: linear-gradient(180deg, #ffffff 0%, #f8fbff 100%);\n      border: 1px solid var(--ols-border);\n      border-radius: 28px;\n      box-shadow: 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none;\n      border: 1px solid rgba(28, 36, 75, 0.14);\n      background: #ffffff;\n      color: var(--ols-navy);\n      border-radius: 999px;\n      padding: 10px 15px;\n      font-family: Poppins, Arial, sans-serif;\n      font-size: 14px;\n      font-weight: 600;\n      cursor: pointer;\n      transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease, color 0.2s ease;\n    }\n\n    #ols-xef2-linear-lone-pair-card .ols-btn:hover {\n      transform: translateY(-2px);\n      box-shadow: 0 8px 20px rgba(28, 36, 75, 0.12);\n    }\n\n    #ols-xef2-linear-lone-pair-card .ols-btn.is-active {\n      background: var(--ols-navy);\n      color: #ffffff;\n      border-color: var(--ols-navy);\n    }\n\n    #ols-xef2-linear-lone-pair-card .ols-explanation {\n      padding: 22px 26px 26px;\n      background: #ffffff;\n      border-top: 1px solid rgba(28, 36, 75, 0.08);\n    }\n\n    #ols-xef2-linear-lone-pair-card .ols-key-message {\n      margin: 0;\n      padding: 16px 18px;\n      border-radius: 18px;\n      background: var(--ols-soft-blue);\n      border: 1px solid rgba(31, 122, 224, 0.14);\n      font-size: 16px;\n      line-height: 1.65;\n      font-weight: 300;\n      color: rgba(28, 36, 75, 0.88);\n    }\n\n    #ols-xef2-linear-lone-pair-card .ols-key-message strong {\n      font-weight: 700;\n      color: var(--ols-navy);\n    }\n\n    #ols-xef2-linear-lone-pair-card .ols-explanation-grid {\n      display: grid;\n      grid-template-columns: repeat(3, minmax(0, 1fr));\n      gap: 14px;\n      margin-top: 16px;\n    }\n\n    #ols-xef2-linear-lone-pair-card .ols-info-box {\n      border-radius: 18px;\n      padding: 16px;\n      background: #f8fbff;\n      border: 1px solid rgba(28, 36, 75, 0.1);\n    }\n\n    #ols-xef2-linear-lone-pair-card .ols-info-box strong {\n      display: block;\n      font-size: 15px;\n      margin-bottom: 6px;\n      color: var(--ols-navy);\n    }\n\n    #ols-xef2-linear-lone-pair-card .ols-info-box span {\n      display: block;\n      font-size: 14px;\n      line-height: 1.55;\n      font-weight: 300;\n      color: rgba(28, 36, 75, 0.8);\n    }\n\n    #ols-xef2-linear-lone-pair-card .ols-examples-box {\n      margin-top: 16px;\n      padding: 16px 18px;\n      border-radius: 18px;\n      background: #fffaf1;\n      border: 1px solid rgba(201, 151, 58, 0.24);\n      color: rgba(28, 36, 75, 0.88);\n      font-size: 15px;\n      line-height: 1.65;\n      font-weight: 300;\n    }\n\n    #ols-xef2-linear-lone-pair-card .ols-examples-box strong {\n      font-weight: 700;\n      color: var(--ols-navy);\n    }\n\n    @media (max-width: 820px) {\n      #ols-xef2-linear-lone-pair-card .ols-viewer-wrap {\n        height: 500px;\n      }\n\n      #ols-xef2-linear-lone-pair-card .ols-explanation-grid {\n        grid-template-columns: 1fr;\n      }\n\n      #ols-xef2-linear-lone-pair-card .ols-viewer-badge {\n        top: 12px;\n        right: 12px;\n        font-size: 12px;\n      }\n    }\n\n    @media (max-width: 520px) {\n      #ols-xef2-linear-lone-pair-card .ols-model-header,\n      #ols-xef2-linear-lone-pair-card .ols-explanation {\n        padding-left: 18px;\n        padding-right: 18px;\n      }\n\n      #ols-xef2-linear-lone-pair-card .ols-viewer-wrap {\n        height: 430px;\n      }\n\n      #ols-xef2-linear-lone-pair-card .ols-controls {\n        padding: 14px;\n      }\n\n      #ols-xef2-linear-lone-pair-card .ols-btn {\n        width: 100%;\n      }\n\n      #ols-xef2-linear-lone-pair-card .ols-viewer-badge {\n        left: 12px;\n        right: 12px;\n        text-align: center;\n      }\n    }\n  <\/style>\n\n  <div class=\"ols-model-card\">\n    <div class=\"ols-model-header\">\n      <div class=\"ols-pill\">3D molecule shape model<\/div>\n      <h2 class=\"ols-model-title\">Linear Shape of XeF<sub>2<\/sub><\/h2>\n      <p class=\"ols-model-subtitle\">\n        Xenon difluoride is linear even though the central xenon atom has lone pairs. XeF<sub>2<\/sub> has two Xe-F bonding pairs and three lone pairs. The five electron regions arrange themselves as a trigonal bipyramidal electron-pair arrangement, with the three lone pairs in equatorial positions and the two Xe-F bonds in opposite axial positions.\n      <\/p>\n    <\/div>\n\n    <div class=\"ols-viewer-wrap\">\n      <div id=\"olsXeF2Viewer\"><\/div>\n      <div class=\"ols-viewer-badge\">Drag to rotate \u2022 Scroll to zoom \u2022 Red clouds show the three equatorial lone pairs<\/div>\n      <div class=\"ols-angle-badge\" id=\"olsXeF2AngleBadge\">Bond angle: 180\u00b0<\/div>\n    <\/div>\n\n    <div class=\"ols-controls\">\n      <button type=\"button\" class=\"ols-btn is-active\" id=\"olsXeF2RotateBtn\">Pause rotation<\/button>\n      <button type=\"button\" class=\"ols-btn\" id=\"olsXeF2ResetBtn\">Reset view<\/button>\n    <\/div>\n\n    <div class=\"ols-explanation\">\n      <p class=\"ols-key-message\">\n        <strong>Key idea:<\/strong> XeF<sub>2<\/sub> has <strong>two bonding pairs<\/strong> and <strong>three lone pairs<\/strong> around xenon. This is different from simple linear molecules such as BeCl<sub>2<\/sub> or CO<sub>2<\/sub>, where the central atom has two bonding regions and no lone pairs. In XeF<sub>2<\/sub>, the three lone pairs occupy the <strong>equatorial plane<\/strong>, approximately <strong>120\u00b0<\/strong> apart. This leaves the two Xe-F bonds in opposite axial positions, producing a <strong>linear molecular shape<\/strong> with a bond angle of <strong>180\u00b0<\/strong>.\n      <\/p>\n\n      <div class=\"ols-explanation-grid\">\n        <div class=\"ols-info-box\">\n          <strong>Central atom<\/strong>\n          <span>Xenon is the central atom and sits at the centre of the model.<\/span>\n        <\/div>\n\n        <div class=\"ols-info-box\">\n          <strong>Lone pairs<\/strong>\n          <span>The three red electron clouds represent the three lone pairs in equatorial positions.<\/span>\n        <\/div>\n\n        <div class=\"ols-info-box\">\n          <strong>Shape outcome<\/strong>\n          <span>Two axial bonds and three equatorial lone pairs produce a linear molecular shape.<\/span>\n        <\/div>\n      <\/div>\n\n      <div class=\"ols-examples-box\">\n        <strong>Common examples of this linear type:<\/strong>\n        XeF<sub>2<\/sub>, I<sub>3<\/sub><sup>\u2212<\/sup>, ICl<sub>2<\/sub><sup>\u2212<\/sup>, IBr<sub>2<\/sub><sup>\u2212<\/sup> and BrF<sub>2<\/sub><sup>\u2212<\/sup>. These are linear because the central atom has two bonding pairs and three lone pairs, not because it has only two electron regions.\n      <\/div>\n    <\/div>\n  <\/div>\n\n  <script src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/JS\/lp_linear.js\"><\/script>\n<\/section>\n\n      <section class=\"ols-h5p-card\">\n        <h2>Check Your Understanding<\/h2>\n        <p>Use these short activities to check electron-pair repulsion, linear shape, BeCl<sub>2<\/sub> and the 180\u00b0 bond angle.<\/p>\n        <div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-176\" class=\"h5p-iframe\" data-content-id=\"176\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Linear.1 Drag: Linear Molecular Shape Key Concepts\"><\/iframe><\/div><\/div>\n        <div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-177\" class=\"h5p-iframe\" data-content-id=\"177\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Linear.2 MCQ: Electron Pairs in BeCl2\"><\/iframe><\/div><\/div>\n        <div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-178\" class=\"h5p-iframe\" data-content-id=\"178\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Linear.3 MCQ: Bond Angle in BeCl2\"><\/iframe><\/div><\/div>\n        <div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-179\" class=\"h5p-iframe\" data-content-id=\"179\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Linear.4 MCQ: Exam Explanation for BeCl2\"><\/iframe><\/div><\/div>\n      <\/section>\n\n      <article class=\"ols-note-card purple\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">\u2713<\/div>\n          <h2>QuickSnap<\/h2>\n        <\/div>\n        <p>The linear shape is produced when a central atom has <strong>two bonding pairs<\/strong> and <strong>no lone pairs<\/strong>. The two bonding pairs repel equally and move to opposite sides of the central atom.<\/p>\n        <div class=\"ols-rule-list\">\n          <div class=\"ols-rule-item\"><h3>Electron-pair repulsion<\/h3><p>Electron pairs repel because electrons are negatively charged.<\/p><\/div>\n          <div class=\"ols-rule-item\"><h3>Linear condition<\/h3><p>Two bonding pairs and no lone pairs around the central atom.<\/p><\/div>\n          <div class=\"ols-rule-item\"><h3>Bond angle<\/h3><p>The bonding pairs are furthest apart at 180\u00b0.<\/p><\/div>\n          <div class=\"ols-rule-item\"><h3>Example<\/h3><p>BeCl<sub>2<\/sub> is linear, with a Cl-Be-Cl bond angle of 180\u00b0.<\/p><\/div>\n        <\/div>\n      <\/article>\n\n      <section class=\"ols-course-cta-covalent-shapes\" id=\"olsCourseCtaCovalentShapes001\">\r\n  <style>\r\n    .ols-course-cta-covalent-shapes,\r\n    .ols-course-cta-covalent-shapes * {\r\n      box-sizing: border-box;\r\n    }\r\n\r\n    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height: 420px;\r\n        border-radius: 18px;\r\n      }\r\n\r\n      .ols-course-cta-covalent-shapes .ols-animation-play-circle {\r\n        width: 76px;\r\n        height: 76px;\r\n      }\r\n\r\n      .ols-course-cta-covalent-shapes .ols-animation-play-icon {\r\n        border-top-width: 14px;\r\n        border-bottom-width: 14px;\r\n        border-left-width: 22px;\r\n      }\r\n\r\n      .ols-course-cta-covalent-shapes .ols-animation-pause-button {\r\n        left: 12px;\r\n        bottom: 12px;\r\n        min-width: 84px;\r\n        padding: 9px 14px;\r\n        font-size: 13px;\r\n      }\r\n\r\n      .ols-course-cta-covalent-shapes .ols-course-button {\r\n        width: 100%;\r\n      }\r\n    }\r\n  <\/style>\r\n\r\n  <div class=\"ols-course-cta-card\">\r\n\r\n    <div class=\"ols-course-cta-top\">\r\n\r\n      <a class=\"ols-course-cta-image-link\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/product\/covalent-bonding-shapes-of-molecules-edexcel-t2ab\/\" aria-label=\"Open the Edexcel A Level Chemistry Topic 2A\/B Covalent Bonding, Structure and Shapes of Molecules course page\">\r\n\r\n        <div class=\"ols-course-cta-image\">\r\n          <img decoding=\"async\"\r\n            src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/T2AB-Covalent-Bonding-Structure-Shapes-of-Molecules.jpg\"\r\n            alt=\"Edexcel A Level Chemistry Topic 2A\/B Covalent Bonding, Structure and Shapes of Molecules course banner\"\r\n          >\r\n        <\/div>\r\n\r\n      <\/a>\r\n\r\n      <div class=\"ols-course-cta-content\">\r\n\r\n        <div class=\"ols-course-cta-header-row\">\r\n\r\n          <div class=\"ols-course-cta-kicker\">\r\n            Complete Topic 2A\/B Covalent Bonding, Structure & Shapes of Molecules Course\r\n          <\/div>\r\n\r\n          <a class=\"ols-course-button ols-course-button-top\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/product\/covalent-bonding-shapes-of-molecules-edexcel-t2ab\/\">\r\n            View Course\r\n          <\/a>\r\n\r\n        <\/div>\r\n\r\n        <h2>\r\n          Master Covalent Bonding, Structure and Shapes of Molecules for Edexcel A Level Chemistry\r\n        <\/h2>\r\n\r\n      <\/div>\r\n\r\n    <\/div>\r\n\r\n    <div class=\"ols-course-cta-intro-stats\">\r\n\r\n      <p class=\"ols-course-cta-intro\">\r\n        Continue from these free revision notes into the full Topic 2A\/B Covalent Bonding, Structure and Shapes of Molecules course, with guided video teaching, diagnostic MCQ practice, teacher-marked short-answer questions and a specification assignment with a personalised progress report.\r\n      <\/p>\r\n\r\n      <div class=\"ols-course-cta-stats\">\r\n\r\n        <div class=\"ols-course-stat\">\r\n          <span>Guided learning<\/span>\r\n          <strong>13 hours<\/strong>\r\n        <\/div>\r\n\r\n        <div class=\"ols-course-stat\">\r\n          <span>Video lessons<\/span>\r\n          <strong>281 mins<\/strong>\r\n        <\/div>\r\n\r\n        <div class=\"ols-course-stat\">\r\n          <span>MCQ practice<\/span>\r\n          <strong>37 marks<\/strong>\r\n        <\/div>\r\n\r\n        <div class=\"ols-course-stat\">\r\n          <span>SAQ practice<\/span>\r\n          <strong>169 marks<\/strong>\r\n        <\/div>\r\n\r\n      <\/div>\r\n\r\n    <\/div>\r\n\r\n    <div class=\"ols-course-cta-features\">\r\n\r\n      <div class=\"ols-course-feature\">\r\n        <h3>Guided video teaching<\/h3>\r\n        <p>\r\n          Learn covalent bonding, dot-and-cross diagrams, giant covalent structures, electronegativity, polarity and molecular shapes through structured video lessons with worked examples and walkthroughs.\r\n        <\/p>\r\n      <\/div>\r\n\r\n      <div class=\"ols-course-feature\">\r\n        <h3>Instant MCQ feedback<\/h3>\r\n        <p>\r\n          Auto-marked MCQ quizzes provide immediate diagnostic feedback for every answer choice.\r\n        <\/p>\r\n      <\/div>\r\n\r\n      <div class=\"ols-course-feature\">\r\n        <h3>Teacher-marked SAQs<\/h3>\r\n        <p>\r\n          Submit written exam responses and receive chemistry specialist feedback with improvement guidance.\r\n        <\/p>\r\n      <\/div>\r\n\r\n      <div class=\"ols-course-feature\">\r\n        <h3>Progress tracking<\/h3>\r\n        <p>\r\n          Identify strengths and weaknesses across covalent bonding, giant covalent structures, polarity, VSEPR theory and molecular shapes with targeted reporting.\r\n        <\/p>\r\n      <\/div>\r\n\r\n    <\/div>\r\n\r\n    <div class=\"ols-course-animation-wrap\">\r\n\r\n      <h3 class=\"ols-course-animation-title\">\r\n        See how the course works\r\n      <\/h3>\r\n\r\n      <div class=\"ols-animation-frame-shell\">\r\n        <iframe\r\n          id=\"olsCourseAnimationFrame001\"\r\n          title=\"OLS course preview animation\"\r\n          loading=\"lazy\"\r\n          referrerpolicy=\"no-referrer\">\r\n        <\/iframe>\r\n\r\n        <button\r\n          class=\"ols-animation-start-overlay\"\r\n          id=\"olsCourseAnimationStart001\"\r\n          type=\"button\"\r\n          aria-label=\"Play OLS course preview animation\">\r\n          <span class=\"ols-animation-start-content\">\r\n            <span class=\"ols-animation-play-circle\" aria-hidden=\"true\">\r\n              <span class=\"ols-animation-play-icon\"><\/span>\r\n            <\/span>\r\n            <span class=\"ols-animation-start-text\">\r\n              Play course preview animation\r\n            <\/span>\r\n          <\/span>\r\n        <\/button>\r\n\r\n        <button\r\n          class=\"ols-animation-pause-button\"\r\n          id=\"olsCourseAnimationPause001\"\r\n          type=\"button\"\r\n          aria-label=\"Pause course preview animation\">\r\n          Pause\r\n        <\/button>\r\n      <\/div>\r\n\r\n      <p class=\"ols-course-video-status\">\r\n        Click play to start the course preview animation.\r\n      <\/p>\r\n\r\n    <\/div>\r\n\r\n    <div class=\"ols-course-cta-bottom\">\r\n\r\n      <a class=\"ols-course-button\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/product\/covalent-bonding-shapes-of-molecules-edexcel-t2ab\/\">\r\n        View Covalent Bonding & Shapes of Molecules Topic 2A\/B Course\r\n      <\/a>\r\n\r\n    <\/div>\r\n\r\n  <\/div>\r\n\r\n  <template id=\"olsCourseAnimationTemplate001\">\r\n<!DOCTYPE html>\r\n<html lang=\"en\">\r\n<head>\r\n<meta charset=\"UTF-8\">\r\n<meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">\r\n<title>OLS Combined Promo Animation<\/title>\r\n\r\n<style>\r\n*{box-sizing:border-box;}\r\n\r\nhtml.ols-animation-paused *,\r\nhtml.ols-animation-paused *::before,\r\nhtml.ols-animation-paused *::after{\r\n  animation-play-state:paused!important;\r\n}\r\n\r\n:root{\r\n  --ols-video-screen-w:1180;\r\n  --ols-video-screen-h:664;\r\n  --ols-video-screen-scale:1;\r\n  --ols-mcq-screen-w:1360;\r\n  --ols-mcq-screen-h:1130;\r\n  --ols-mcq-screen-scale:1;\r\n  --ols-saq-screen-w:1360;\r\n  --ols-saq-screen-h:965;\r\n  --ols-saq-screen-scale:1;\r\n}\r\n\r\nhtml,\r\nbody{\r\n  width:100%;\r\n  height:100%;\r\n}\r\n\r\nbody{\r\n  margin:0;\r\n  overflow:hidden;\r\n  font-family:Poppins,Arial,sans-serif;\r\n  background:#e9efff;\r\n}\r\n\r\n.ols-combined-stage{\r\n  position:relative;\r\n  width:100vw;\r\n  height:100vh;\r\n  overflow:hidden;\r\n  background:\r\n    radial-gradient(circle at top left,rgba(70,127,247,0.14),transparent 34%),\r\n    linear-gradient(135deg,#f8fbff 0%,#e9efff 100%);\r\n}\r\n\r\n.ols-scene{\r\n  position:absolute;\r\n  inset:0;\r\n  width:100vw;\r\n  height:100vh;\r\n  opacity:0;\r\n  visibility:hidden;\r\n  pointer-events:none;\r\n}\r\n\r\n.ols-scene.active{\r\n  opacity:1;\r\n  visibility:visible;\r\n  pointer-events:auto;\r\n}\r\n\r\n.ols-scene.fade-out{\r\n  animation:olsSceneFadeOut 0.85s ease forwards;\r\n}\r\n\r\n@keyframes olsSceneFadeOut{\r\n  to{\r\n    opacity:0;\r\n    visibility:hidden;\r\n  }\r\n}\r\n\r\n.ols-title-cursor{\r\n  display:inline-block;\r\n  width:5px;\r\n  height:0.85em;\r\n  background:#1C244B;\r\n  margin-left:8px;\r\n  transform:translateY(8px);\r\n  animation:olsBlink 0.8s infinite;\r\n}\r\n\r\n.cursor{\r\n  display:inline-block;\r\n  width:3px;\r\n  height:28px;\r\n  background:#1c244b;\r\n  margin-left:3px;\r\n  transform:translateY(5px);\r\n  animation:olsBlink 0.8s infinite;\r\n}\r\n\r\n@keyframes olsBlink{\r\n  0%,45%{opacity:1;}\r\n  46%,100%{opacity:0;}\r\n}\r\n\r\n.ols-video-stage,\r\n.ols-mcq-stage,\r\n.ols-saq-stage{\r\n  width:100vw;\r\n  height:100vh;\r\n  display:flex;\r\n  justify-content:center;\r\n  align-items:center;\r\n  padding:0;\r\n  overflow:hidden;\r\n  background:\r\n    radial-gradient(circle at top left,rgba(70,127,247,0.14),transparent 34%),\r\n    linear-gradient(135deg,#f8fbff 0%,#e9efff 100%);\r\n}\r\n\r\n.ols-video-title-screen,\r\n.ols-mcq-intro-screen,\r\n.ols-saq-intro{\r\n  position:absolute;\r\n  inset:0;\r\n  z-index:50;\r\n  display:flex;\r\n  justify-content:center;\r\n  align-items:center;\r\n  background:\r\n    radial-gradient(circle at top left,rgba(70,127,247,0.14),transparent 34%),\r\n    linear-gradient(135deg,#f8fbff 0%,#e9efff 100%);\r\n  opacity:1;\r\n  visibility:visible;\r\n  pointer-events:none;\r\n}\r\n\r\n.ols-video-title-screen.hide{animation:olsVideoTitleFadeOut 0.85s ease forwards;}\r\n.ols-mcq-intro-screen.hide{animation:olsMcqIntroFadeOut 0.85s ease forwards;}\r\n.ols-saq-intro.hide{animation:olsSaqIntroFadeOut 0.85s ease forwards;}\r\n\r\n@keyframes olsVideoTitleFadeOut{to{opacity:0;visibility:hidden;}}\r\n@keyframes olsMcqIntroFadeOut{to{opacity:0;visibility:hidden;}}\r\n@keyframes olsSaqIntroFadeOut{to{opacity:0;visibility:hidden;}}\r\n\r\n.ols-video-title-wrap,\r\n.ols-mcq-intro-title-wrap,\r\n.ols-saq-intro-title-wrap{\r\n  max-width:1250px;\r\n  padding:0 34px;\r\n  text-align:center;\r\n}\r\n\r\n.ols-video-title,\r\n.ols-mcq-intro-title,\r\n.ols-saq-intro-title{\r\n  margin:0;\r\n  font-family:Poppins,Arial,sans-serif;\r\n  font-size:clamp(52px,8vw,124px);\r\n  font-weight:600;\r\n  line-height:1.08;\r\n  color:#1C244B;\r\n  text-shadow:-9px 0 9px rgba(28,36,75,0.16);\r\n  letter-spacing:-0.045em;\r\n}\r\n\r\n#videoTitleText,\r\n#mcqIntroTitleText,\r\n#saqIntroTitleText{\r\n  white-space:pre-wrap;\r\n}\r\n\r\n.ols-video-scene{\r\n  width:100%;\r\n  height:100%;\r\n  display:flex;\r\n  justify-content:center;\r\n  align-items:center;\r\n  opacity:0;\r\n  visibility:hidden;\r\n}\r\n\r\n.ols-video-scene.show{\r\n  visibility:visible;\r\n  animation:olsVideoSceneIn 1s ease forwards;\r\n}\r\n\r\n@keyframes olsVideoSceneIn{to{opacity:1;}}\r\n\r\n.ols-video-scale-wrap{\r\n  width:calc(var(--ols-video-screen-w) * 1px);\r\n  height:calc(var(--ols-video-screen-h) * 1px);\r\n  transform:scale(var(--ols-video-screen-scale));\r\n  transform-origin:center center;\r\n  display:flex;\r\n  justify-content:center;\r\n  align-items:center;\r\n}\r\n\r\n.ols-video-card{\r\n  width:1180px;\r\n  height:664px;\r\n  border-radius:28px;\r\n  overflow:hidden;\r\n  background:#1C244B;\r\n  box-shadow:0 28px 80px rgba(28,36,75,0.28);\r\n  transform:translateY(24px) scale(0.96);\r\n  opacity:0;\r\n}\r\n\r\n.ols-video-scene.show .ols-video-card{\r\n  animation:olsVideoCardIn 1s cubic-bezier(.18,.89,.32,1.12) forwards;\r\n  animation-delay:0.2s;\r\n}\r\n\r\n@keyframes olsVideoCardIn{\r\n  to{\r\n    transform:translateY(0) scale(1);\r\n    opacity:1;\r\n  }\r\n}\r\n\r\n.ols-video-card video{\r\n  display:block;\r\n  width:100%;\r\n  height:100%;\r\n  aspect-ratio:16 \/ 9;\r\n  object-fit:cover;\r\n  border:0;\r\n}\r\n\r\n.ols-mcq-scale-wrap,\r\n.ols-saq-scale-wrap{\r\n  width:calc(var(--ols-mcq-screen-w) * 1px);\r\n  height:calc(var(--ols-mcq-screen-h) * 1px);\r\n  transform:scale(var(--ols-mcq-screen-scale));\r\n  transform-origin:center center;\r\n  display:flex;\r\n  justify-content:center;\r\n  align-items:flex-start;\r\n}\r\n\r\n.ols-saq-scale-wrap{\r\n  width:calc(var(--ols-saq-screen-w) * 1px);\r\n  height:calc(var(--ols-saq-screen-h) * 1px);\r\n  transform:scale(var(--ols-saq-screen-scale));\r\n}\r\n\r\n.ols-mcq-screen{\r\n  width:1360px;\r\n  height:1130px;\r\n  border-radius:22px;\r\n  overflow:hidden;\r\n  background:#eaf0ff;\r\n  box-shadow:0 26px 70px rgba(28,36,75,0.22);\r\n  opacity:0;\r\n  transform:translateY(24px) scale(0.96);\r\n}\r\n\r\n.ols-mcq-screen.show{\r\n  animation:olsMcqScreenEnter 1s ease forwards;\r\n}\r\n\r\n@keyframes olsMcqScreenEnter{\r\n  from{opacity:0;transform:translateY(24px) scale(0.96);}\r\n  to{opacity:1;transform:translateY(0) scale(1);}\r\n}\r\n\r\n.mcq-question-area{\r\n  background:#eaf0ff;\r\n  padding:28px 30px 30px;\r\n  position:relative;\r\n  height:610px;\r\n}\r\n\r\n.mcq-question-lead{\r\n  margin:0 0 14px;\r\n  font-size:24px;\r\n  line-height:1.35;\r\n  color:#111827;\r\n}\r\n\r\n.mcq-ionic-table{\r\n  border-collapse:collapse;\r\n  width:500px;\r\n  margin-bottom:8px;\r\n  font-size:21px;\r\n  color:#111827;\r\n}\r\n\r\n.mcq-ionic-table th,\r\n.mcq-ionic-table td{\r\n  border:1.5px solid #c9ced8;\r\n  padding:12px 18px;\r\n  text-align:center;\r\n}\r\n\r\n.mcq-ionic-table th{\r\n  background:#f2f2f2;\r\n  font-weight:700;\r\n}\r\n\r\n.mcq-ionic-table td{\r\n  background:#eaf0ff;\r\n}\r\n\r\n.mcq-question-main{\r\n  margin:6px 0 28px;\r\n  font-size:24px;\r\n  line-height:1.35;\r\n  color:#111827;\r\n}\r\n\r\n.mcq-options-wrap{\r\n  display:flex;\r\n  flex-direction:column;\r\n  gap:17px;\r\n  max-width:1200px;\r\n}\r\n\r\n.mcq-option-row{\r\n  display:flex;\r\n  align-items:center;\r\n  min-height:34px;\r\n  position:relative;\r\n}\r\n\r\n.mcq-radio{\r\n  width:28px;\r\n  height:28px;\r\n  border-radius:50%;\r\n  border:2px solid #6b7280;\r\n  margin-right:16px;\r\n  background:transparent;\r\n  position:relative;\r\n  flex:0 0 auto;\r\n}\r\n\r\n.mcq-radio::after{\r\n  content:\"\";\r\n  position:absolute;\r\n  inset:5px;\r\n  border-radius:50%;\r\n  background:#6b7280;\r\n  opacity:0;\r\n  transform:scale(0.4);\r\n  transition:opacity 0.25s ease,transform 0.25s ease;\r\n}\r\n\r\n.mcq-option-row.selected .mcq-radio::after{\r\n  opacity:1;\r\n  transform:scale(1);\r\n}\r\n\r\n.mcq-radio-ripple{\r\n  position:absolute;\r\n  left:14px;\r\n  top:50%;\r\n  width:28px;\r\n  height:28px;\r\n  border-radius:50%;\r\n  border:2px solid rgba(28,36,75,0.28);\r\n  transform:translate(-50%,-50%) scale(1);\r\n  opacity:0;\r\n  pointer-events:none;\r\n}\r\n\r\n.mcq-option-row.clicking .mcq-radio-ripple{\r\n  animation:mcqRipple 0.75s ease forwards;\r\n}\r\n\r\n@keyframes mcqRipple{\r\n  0%{opacity:0.65;transform:translate(-50%,-50%) scale(1);}\r\n  100%{opacity:0;transform:translate(-50%,-50%) scale(2.5);}\r\n}\r\n\r\n.mcq-option-label{\r\n  font-size:23px;\r\n  color:#111827;\r\n}\r\n\r\n.mcq-specific-feedback{\r\n  display:inline-flex;\r\n  align-items:center;\r\n  margin-left:18px;\r\n  min-height:38px;\r\n  opacity:0;\r\n  transform:translateX(-8px);\r\n}\r\n\r\n.mcq-specific-feedback.show{\r\n  opacity:1;\r\n  transform:translateX(0);\r\n  transition:opacity 0.35s ease,transform 0.35s ease;\r\n}\r\n\r\n.mcq-cross-icon{\r\n  width:26px;\r\n  height:26px;\r\n  border-radius:50%;\r\n  border:2px solid #d83255;\r\n  color:#d83255;\r\n  display:inline-flex;\r\n  justify-content:center;\r\n  align-items:center;\r\n  font-size:18px;\r\n  font-weight:700;\r\n  margin-right:12px;\r\n  opacity:0;\r\n  transform:scale(0.4);\r\n}\r\n\r\n.mcq-cross-icon.show{\r\n  animation:mcqCrossPop 0.35s ease forwards;\r\n}\r\n\r\n@keyframes mcqCrossPop{\r\n  70%{opacity:1;transform:scale(1.18);}\r\n  100%{opacity:1;transform:scale(1);}\r\n}\r\n\r\n.mcq-specific-feedback-text{\r\n  display:inline-block;\r\n  background:#fff4b8;\r\n  color:#111827;\r\n  padding:8px 16px;\r\n  font-size:22px;\r\n  line-height:1.35;\r\n  min-width:850px;\r\n  min-height:44px;\r\n}\r\n\r\n.mcq-submit-button{\r\n  position:absolute;\r\n  right:34px;\r\n  bottom:30px;\r\n  border:0;\r\n  border-radius:999px;\r\n  background:#1C244B;\r\n  color:#ffffff;\r\n  padding:14px 28px;\r\n  font-size:18px;\r\n  font-weight:600;\r\n  box-shadow:0 14px 32px rgba(28,36,75,0.25);\r\n  cursor:default;\r\n  transition:transform 0.2s ease,box-shadow 0.2s ease,background 0.2s ease;\r\n}\r\n\r\n.mcq-submit-button.clicked{\r\n  transform:translateY(2px) scale(0.97);\r\n  background:#26315f;\r\n  box-shadow:0 7px 18px rgba(28,36,75,0.22);\r\n}\r\n\r\n.mcq-general-feedback{\r\n  height:520px;\r\n  background:#fff3c9;\r\n  color:#8a6a00;\r\n  padding:26px 30px 28px;\r\n  font-size:23px;\r\n  line-height:1.34;\r\n  opacity:0;\r\n  transform:translateY(20px);\r\n  transition:opacity 0.7s ease,transform 0.7s ease;\r\n  overflow:hidden;\r\n}\r\n\r\n.mcq-general-feedback.show{\r\n  opacity:1;\r\n  transform:translateY(0);\r\n}\r\n\r\n#mcqGeneralText{\r\n  white-space:pre-wrap;\r\n}\r\n\r\n.mcq-specific-cursor{background:#111827;}\r\n.mcq-general-cursor{background:#8a6a00;}\r\n\r\n.ols-saq-screen{\r\n  width:1360px;\r\n  height:965px;\r\n  border-radius:22px;\r\n  overflow:hidden;\r\n  background:#eaf0ff;\r\n  box-shadow:0 26px 70px rgba(28,36,75,0.22);\r\n  opacity:0;\r\n  transform:translateY(24px) scale(0.96);\r\n}\r\n\r\n.ols-saq-screen.show{\r\n  animation:olsSaqScreenEnter 1s ease forwards;\r\n}\r\n\r\n@keyframes olsSaqScreenEnter{\r\n  from{opacity:0;transform:translateY(24px) scale(0.96);}\r\n  to{opacity:1;transform:translateY(0) scale(1);}\r\n}\r\n\r\n.saq-question-area{\r\n  height:335px;\r\n  background:#eaf0ff;\r\n  padding:30px 40px 32px;\r\n}\r\n\r\n.saq-question-text{\r\n  font-size:25px;\r\n  line-height:1.42;\r\n  color:#111827;\r\n  margin-bottom:22px;\r\n}\r\n\r\n.saq-student-box{\r\n  height:195px;\r\n  background:#f3f4f6;\r\n  border:2px solid #cfd6e3;\r\n  border-radius:8px;\r\n  padding:23px 26px;\r\n  font-size:24px;\r\n  line-height:1.55;\r\n  color:#4b5563;\r\n  position:relative;\r\n  overflow:hidden;\r\n}\r\n\r\n.saq-teacher-feedback{\r\n  height:630px;\r\n  background:#dff3e6;\r\n  color:#075f3b;\r\n  padding:28px 40px 30px;\r\n  font-size:23px;\r\n  line-height:1.47;\r\n  opacity:0;\r\n  transform:translateY(20px);\r\n  transition:opacity 0.7s ease,transform 0.7s ease;\r\n  overflow:hidden;\r\n}\r\n\r\n.saq-teacher-feedback.show{\r\n  opacity:1;\r\n  transform:translateY(0);\r\n}\r\n\r\n#saqTeacherText{\r\n  white-space:pre-wrap;\r\n}\r\n\r\n.saq-teacher-cursor{\r\n  background:#075f3b;\r\n}\r\n\r\n@media(max-width:900px){\r\n  .ols-video-title,\r\n  .ols-mcq-intro-title,\r\n  .ols-saq-intro-title{\r\n    font-size:clamp(42px,11vw,78px);\r\n    line-height:1.12;\r\n  }\r\n\r\n  .ols-title-cursor{\r\n    width:4px;\r\n    margin-left:6px;\r\n  }\r\n\r\n  .ols-video-card{\r\n    border-radius:20px;\r\n  }\r\n}\r\n<\/style>\r\n<\/head>\r\n\r\n<body>\r\n<div class=\"ols-combined-stage\">\r\n\r\n  <section id=\"sceneVideo\" class=\"ols-scene active\">\r\n    <div class=\"ols-video-stage\">\r\n      <div id=\"videoTitleScreen\" class=\"ols-video-title-screen\">\r\n        <div class=\"ols-video-title-wrap\">\r\n          <h1 class=\"ols-video-title\">\r\n            <span id=\"videoTitleText\"><\/span><span id=\"videoTitleCursor\" class=\"ols-title-cursor\"><\/span>\r\n          <\/h1>\r\n        <\/div>\r\n      <\/div>\r\n\r\n      <section id=\"videoScene\" class=\"ols-video-scene\">\r\n        <div class=\"ols-video-scale-wrap\">\r\n          <div class=\"ols-video-card\">\r\n            <video\r\n              id=\"lessonVideo\"\r\n              src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/Virtual-Lesson.mp4\"\r\n              muted\r\n              playsinline\r\n              preload=\"auto\">\r\n            <\/video>\r\n          <\/div>\r\n        <\/div>\r\n      <\/section>\r\n    <\/div>\r\n  <\/section>\r\n\r\n  <section id=\"sceneMcq\" class=\"ols-scene\">\r\n    <div class=\"ols-mcq-stage\">\r\n      <div id=\"mcqIntroScreen\" class=\"ols-mcq-intro-screen\">\r\n        <div class=\"ols-mcq-intro-title-wrap\">\r\n          <h1 class=\"ols-mcq-intro-title\">\r\n            <span id=\"mcqIntroTitleText\"><\/span><span id=\"mcqIntroTitleCursor\" class=\"ols-title-cursor\"><\/span>\r\n          <\/h1>\r\n        <\/div>\r\n      <\/div>\r\n\r\n      <div class=\"ols-mcq-scale-wrap\">\r\n        <main id=\"mcqScreen\" class=\"ols-mcq-screen\">\r\n          <section class=\"mcq-question-area\">\r\n            <p class=\"mcq-question-lead\">The shapes of some species are being compared.<\/p>\r\n\r\n            <p class=\"mcq-question-main\">Which species is not tetrahedral?<\/p>\r\n\r\n            <div class=\"mcq-options-wrap\">\r\n              <div id=\"mcqWrongOption\" class=\"mcq-option-row\">\r\n                <span class=\"mcq-radio\"><\/span>\r\n                <span class=\"mcq-radio-ripple\"><\/span>\r\n                <span class=\"mcq-option-label\">methane, CH<sub>4<\/sub><\/span>\r\n\r\n                <span id=\"mcqSpecificFeedback\" class=\"mcq-specific-feedback\">\r\n                  <span id=\"mcqCrossIcon\" class=\"mcq-cross-icon\">\u00d7<\/span>\r\n                  <span class=\"mcq-specific-feedback-text\">\r\n                    <span id=\"mcqSpecificText\"><\/span><span id=\"mcqSpecificCursor\" class=\"cursor mcq-specific-cursor\" style=\"display:none;\"><\/span>\r\n                  <\/span>\r\n                <\/span>\r\n              <\/div>\r\n\r\n              <div class=\"mcq-option-row\"><span class=\"mcq-radio\"><\/span><span class=\"mcq-radio-ripple\"><\/span><span class=\"mcq-option-label\">ammonium ion, NH<sub>4<\/sub><sup>+<\/sup><\/span><\/div>\r\n              <div class=\"mcq-option-row\"><span class=\"mcq-radio\"><\/span><span class=\"mcq-radio-ripple\"><\/span><span class=\"mcq-option-label\">tetrachloroiodate(III) ion, ICl<sub>4<\/sub><sup>\u2212<\/sup><\/span><\/div>\r\n              <div class=\"mcq-option-row\"><span class=\"mcq-radio\"><\/span><span class=\"mcq-radio-ripple\"><\/span><span class=\"mcq-option-label\">tetrachloromethane, CCl<sub>4<\/sub><\/span><\/div>\r\n            <\/div>\r\n\r\n            <button id=\"mcqSubmitButton\" class=\"mcq-submit-button\">Submit answer<\/button>\r\n          <\/section>\r\n\r\n          <section id=\"mcqGeneralFeedback\" class=\"mcq-general-feedback\">\r\n            <span id=\"mcqGeneralText\"><\/span><span id=\"mcqGeneralCursor\" class=\"cursor mcq-general-cursor\" style=\"display:none;\"><\/span>\r\n          <\/section>\r\n        <\/main>\r\n      <\/div>\r\n    <\/div>\r\n  <\/section>\r\n\r\n  <section id=\"sceneSaq\" class=\"ols-scene\">\r\n    <div class=\"ols-saq-stage\">\r\n      <div id=\"saqIntro\" class=\"ols-saq-intro\">\r\n        <div class=\"ols-saq-intro-title-wrap\">\r\n          <h1 class=\"ols-saq-intro-title\">\r\n            <span id=\"saqIntroTitleText\"><\/span><span id=\"saqIntroTitleCursor\" class=\"ols-title-cursor\"><\/span>\r\n          <\/h1>\r\n        <\/div>\r\n      <\/div>\r\n\r\n      <div class=\"ols-saq-scale-wrap\">\r\n        <main id=\"saqScreen\" class=\"ols-saq-screen\">\r\n          <section class=\"saq-question-area\">\r\n            <div class=\"saq-question-text\">\r\n              <strong>(ii)<\/strong>&nbsp;&nbsp; Silicon has a much higher melting temperature than phosphorus.<br>\r\n              Explain this difference in terms of structure and bonding.\r\n            <\/div>\r\n\r\n            <div class=\"saq-student-box\">\r\n              <span id=\"saqStudentText\"><\/span><span id=\"saqStudentCursor\" class=\"cursor\"><\/span>\r\n            <\/div>\r\n          <\/section>\r\n\r\n          <section id=\"saqTeacherFeedback\" class=\"saq-teacher-feedback\">\r\n            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Many strong Si-Si covalent bonds extend throughout the whole lattice, so a large amount of energy is needed to overcome these bonds during melting.\\n\\n\"+\r\n\"Phosphorus exists as simple molecular P\u2084 molecules. The covalent bonds within each P\u2084 molecule are strong, but these are not the main forces overcome during melting. 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The bonding pairs repel equally and arrange themselves 180\u00b0 apart.<\/p>\n          <\/div>\n          <div class=\"ols-faq-item\">\n            <h3>Why is BeCl<sub>2<\/sub> linear?<\/h3>\n            <p>BeCl<sub>2<\/sub> has two Be-Cl bonding pairs around the central Be atom and no lone pairs in the shape model. The two bonding pairs repel equally, so the Cl-Be-Cl bond angle is 180\u00b0.<\/p>\n          <\/div>\n          <div class=\"ols-faq-item\">\n            <h3>Do lone pairs affect the linear shape?<\/h3>\n            <p>Yes. Lone pairs repel more strongly than bonding pairs and can reduce bond angles. BeCl<sub>2<\/sub> is linear because there are no lone pairs on the central atom in the shape model.<\/p>\n          <\/div>\n          <div class=\"ols-faq-item\">\n            <h3>What bond angle should I write for a linear molecule?<\/h3>\n            <p>The bond angle for a linear molecule is 180\u00b0.<\/p>\n          <\/div>\n        <\/div>\n      <\/section>\n\n      <section class=\"ols-related-card\">\n        <h2>Related Topics<\/h2>\n        <p>Use these pages to connect linear shape with the wider bonding and structure topic.<\/p>\n        <div class=\"ols-related-grid\">\n          <a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/covalent-bonding\/\">Covalent Bonding<\/a>\n          <a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/covalent-bonding\/electronegativity\/\">Electronegativity<\/a>\n          <a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/shapes-of-molecules\/trigonal-planar\/\">Trigonal Planar<\/a>\n          <a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/shapes-of-molecules\/tetrahedral\/\">Tetrahedral<\/a>\n          <a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/shapes-of-molecules\/bent\/\">Bent<\/a>\n          <a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/polar-molecules\/\">Polar Molecules<\/a>\n        <\/div>\n      <\/section>\n      <section class=\"ols-attribution-card\">\n        <p><strong>Copyright notice:<\/strong> This OLS revision content, including the explanations, layout, diagrams, tables and embedded learning structure, is authored for Online Learning System by Dr. Mohammed Al-Fatah. 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