{"id":7685,"date":"2026-09-12T11:56:48","date_gmt":"2026-09-12T10:56:48","guid":{"rendered":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/shapes-of-molecules\/seesaw\/"},"modified":"2026-09-26T10:25:09","modified_gmt":"2026-09-26T09:25:09","slug":"seesaw","status":"publish","type":"page","link":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/shapes-of-molecules\/seesaw\/","title":{"rendered":"SeeSaw Molecular Shape"},"content":{"rendered":"\n<section class=\"ols-revision-page ols-seesaw-9ch0-page\">\n  <style>\n    .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      --gold: #c9973a;\n      --grey-text: #667085;\n      --body-text: #1f2937;\n      --border: rgba(28, 36, 75, 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.ols-author-avatar-img { width: 72px; height: 72px; }\n      .ols-author-title { font-size: 24px; }\n      .ols-author-description { font-size: 15px; }\n    }\n  \n    .ols-figure-placeholder .ols-placeholder-box { border: 2px dashed #c9973a; background: #fffaf0; border-radius: 16px; padding: 26px 22px; font-weight: 700; color: #7a4b12; text-align: center; line-height: 1.6; }\n    .ols-figure-placeholder .ols-figure-image { background: transparent; }\n    .ols-figure-placeholder { background: #ffffff; border: 1px solid rgba(28, 36, 75, 0.12); border-radius: 22px; padding: 14px; margin: 18px 0 6px; }\n    .ols-figure-placeholder .ols-figure-caption p { margin: 10px 0 0; font-size: 14px; color: #667085; text-align: center; }\n<\/style>\n\n  <aside class=\"ols-sidebar\">\n  <div class=\"ols-sidebar-header\">\n    <h3>Revision Notes<\/h3>\n    <p>OCR A Level Chemistry A<\/p>\n  <\/div>\n  <div class=\"ols-topic-group\">\n    <h4>2.2.2 Bonding and Structure<\/h4>\n    <ul class=\"ols-topic-list\">\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/\">Section overview<\/a><\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/ionic-bonding\/\">Ionic Bonding<\/a>\n        <ul class=\"ols-subtopic-list\">\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/ionic-bonding\/nature-of-ionic-bonding\/\">Nature of Ionic Bonding<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/ionic-bonding\/polarisation-of-ions\/\">Polarisation of Ions<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/ionic-bonding\/physical-properties-of-ionic-compounds\/\">Physical Properties of Ionic Compounds<\/a><\/li>\n        <\/ul>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/covalent-bonding\/\">Covalent Bonding<\/a>\n        <ul class=\"ols-subtopic-list\">\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/covalent-bonding\/nature-of-covalent-bonding\/\">Nature of Covalent Bonding<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/covalent-bonding\/dative-covalent-bonding\/\">Dative Covalent Bonding<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/covalent-bonding\/electronegativity\/\">Electronegativity<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/covalent-bonding\/giant-covalent-structures\/\">Giant Covalent Structures<\/a><\/li>\n        <\/ul>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/shapes-of-molecules\/\">Shapes of Molecules<\/a>\n        <ul class=\"ols-subtopic-list\">\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/shapes-of-molecules\/linear\/\">Linear<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/shapes-of-molecules\/trigonal-planar\/\">Trigonal Planar<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/shapes-of-molecules\/tetrahedral\/\">Tetrahedral<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/shapes-of-molecules\/trigonal-pyramidal\/\">Trigonal Pyramidal<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/shapes-of-molecules\/bent\/\">Bent<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/shapes-of-molecules\/trigonal-bipyramidal\/\">Trigonal Bipyramidal<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/shapes-of-molecules\/octahedral\/\">Octahedral<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/shapes-of-molecules\/square-planar\/\">Square Planar<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/shapes-of-molecules\/square-pyramidal\/\">Square Pyramidal<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/shapes-of-molecules\/distorted-t\/\">Distorted T<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/shapes-of-molecules\/seesaw\/\">SeeSaw<\/a><\/li>\n        <\/ul>\n      <\/li>\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/polar-molecules\/\">Non-Polar and Polar Molecules<\/a><\/li>\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/bond-enthalpy-and-pauling-values\/\">Bond Enthalpy and Pauling Values<\/a><\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/metallic-bonding\/\">Metallic Bonding<\/a>\n        <ul class=\"ols-subtopic-list\">\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/metallic-bonding\/metallic-bonding-and-structure\/\">Metallic Bonding and Structure<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/metallic-bonding\/physical-properties-of-metals\/\">Physical Properties of Metals<\/a><\/li>\n        <\/ul>\n      <\/li>\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/simple-molecular-structures\/\">Simple Molecular Structures<\/a><\/li>\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/structure-types\/\">Structure Types<\/a><\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/intermolecular-forces\/\">Intermolecular Forces<\/a>\n        <ul class=\"ols-subtopic-list\">\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/intermolecular-forces\/london-forces\/\">London Forces<\/a>\n          <\/li>\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/intermolecular-forces\/permanent-dipole-dipole-forces\/\">Permanent Dipole-Dipole Forces<\/a>\n          <\/li>\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/intermolecular-forces\/hydrogen-bonding\/\">Hydrogen Bonding<\/a>\n          <\/li>\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/intermolecular-forces\/anomalous-properties-of-water\/\">Anomalous Properties of Water<\/a>\n          <\/li>\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/intermolecular-forces\/boiling-temperature-trends\/\">Boiling Point Trends<\/a>\n          <\/li>\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/intermolecular-forces\/choosing-solvents\/\">Choosing Solvents<\/a>\n          <\/li>\n        <\/ul>\n      <\/li>\n    <\/ul>\n  <\/div>\n  <div class=\"ols-topic-group\">\n    <h4>Other OCR Sections<\/h4>\n    <ul class=\"ols-topic-list\">\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-1-basic-concepts-of-organic-chemistry\/\">4.1.1 Basic Concepts of Organic Chemistry<\/a><\/li>\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-2-alkanes\/\">4.1.2 Alkanes<\/a><\/li>\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/\">4.1.3 Alkenes<\/a><\/li>\n    <\/ul>\n  <\/div>\n<\/aside>\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 = 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href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/\">2.2.2 Bonding and Structure<\/a> \/\n<a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/shapes-of-molecules\/\">Shapes of Molecules<\/a> \/\n<span>SeeSaw Molecular Shape<\/span>\n<\/nav>\n\n      <header class=\"ols-title-card\">\n        <h1>SeeSaw Molecular Shape<\/h1>\n        <p class=\"ols-page-intro\">A focused revision guide to the SeeSaw molecular shape, using SF<sub>4<\/sub> as the key example. This page explains why four bonding pairs and one lone pair around a central atom give a SeeSaw arrangement with bond angles a little smaller than the ideal 120&deg;, 90&deg; and 180&deg;.<\/p>\n\n        <div class=\"ols-badges\">\n          <div class=\"ols-badge\">Paper 1 and 2<\/div>\n<div class=\"ols-badge\">2.2.2: Bonding and Structure<\/div>\n<div class=\"ols-badge\">H432\/01 and H432\/02<\/div>\n        <\/div>\n\n        <div class=\"ols-author\">\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          <div class=\"ols-author-content\">\n            <h2 class=\"ols-author-title\">Written by:<br><span>Dr. Mohammed Al-Fatah<\/span><\/h2>\n            <p class=\"ols-author-description\">Chemistry specialist revision notes for A Level Chemistry.<\/p>\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\"><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><\/svg>\n              View LinkedIn Profile\n            <\/a>\n          <\/div>\n        <\/div>\n      <\/header>\n\n<style>\n  .ols-seesaw-9ch0-page .ols-spec-grid {\n    display: grid;\n    grid-template-columns: repeat(3, minmax(0, 1fr));\n    gap: 14px;\n    margin-top: 18px;\n  }\n  .ols-seesaw-9ch0-page .ols-spec-box {\n    background: #ffffff;\n    border: 1px solid var(--border);\n    border-radius: 18px;\n    padding: 18px;\n    box-shadow: var(--inner-shadow);\n  }\n  .ols-seesaw-9ch0-page .ols-spec-box strong {\n    display: block;\n    font-size: 15px;\n    color: var(--blue);\n    margin-bottom: 6px;\n  }\n  .ols-seesaw-9ch0-page .ols-spec-box span {\n    display: block;\n    font-size: 17px;\n    line-height: 1.55;\n    color: var(--body-text);\n    font-weight: 300;\n    overflow-wrap: anywhere;\n  }\n  .ols-seesaw-9ch0-page .ols-h5p-grid {\n    display: grid;\n    gap: 18px;\n    margin-top: 22px;\n  }\n  .ols-seesaw-9ch0-page .ols-h5p-frame {\n    margin-top: 0;\n  }\n  .ols-seesaw-9ch0-page .ols-formula {\n    white-space: nowrap;\n  }\n  .ols-seesaw-9ch0-page .ols-seesaw-reference-figure .ols-figure-image {\n    min-height: 0;\n    padding: 12px;\n  }\n  .ols-seesaw-9ch0-page .ols-seesaw-reference-figure .ols-figure-image img {\n    width: auto;\n    max-width: 100%;\n    max-height: 320px;\n    object-fit: contain;\n    margin: 0 auto;\n  }\n  @media (max-width: 760px) {\n    .ols-seesaw-9ch0-page .ols-spec-grid {\n      grid-template-columns: 1fr;\n    }\n  }\n<\/style>\n\n<style>\n  .ols-seesaw-9ch0-page .ols-spec-grid {\n    display: grid;\n    grid-template-columns: repeat(3, minmax(0, 1fr));\n    gap: 14px;\n    margin-top: 18px;\n  }\n  .ols-seesaw-9ch0-page .ols-spec-box {\n    background: #ffffff;\n    border: 1px solid var(--border);\n    border-radius: 18px;\n    padding: 18px;\n    box-shadow: var(--inner-shadow);\n  }\n  .ols-seesaw-9ch0-page .ols-spec-box strong {\n    display: block;\n    font-size: 15px;\n    color: var(--blue);\n    margin-bottom: 6px;\n  }\n  .ols-seesaw-9ch0-page .ols-spec-box span {\n    display: block;\n    font-size: 17px;\n    line-height: 1.55;\n    color: var(--body-text);\n    font-weight: 300;\n    overflow-wrap: anywhere;\n  }\n  .ols-seesaw-9ch0-page .ols-h5p-grid {\n    display: grid;\n    gap: 18px;\n    margin-top: 22px;\n  }\n  .ols-seesaw-9ch0-page .ols-h5p-frame {\n    margin-top: 0;\n  }\n  .ols-seesaw-9ch0-page .ols-formula {\n    white-space: nowrap;\n  }\n  .ols-seesaw-9ch0-page .ols-seesaw-reference-figure .ols-figure-image {\n    min-height: 0;\n    padding: 12px;\n  }\n  .ols-seesaw-9ch0-page .ols-seesaw-reference-figure .ols-figure-image img {\n    width: auto;\n    max-width: 100%;\n    max-height: 320px;\n    object-fit: contain;\n    margin: 0 auto;\n  }\n  @media (max-width: 760px) {\n    .ols-seesaw-9ch0-page .ols-spec-grid {\n      grid-template-columns: 1fr;\n    }\n  }\n<\/style>\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 SeeSaw Means<\/h2>\n        <\/div>\n        <p>A <strong>SeeSaw<\/strong> molecule has four atoms bonded to a central atom, with the bonded atoms arranged like a tilted seesaw. The shape forms when there are <strong>four bonding pairs<\/strong> and <strong>one lone pair<\/strong> around the central atom.<\/p>\n        <p>The key example for this page is <strong>SF<sub>4<\/sub><\/strong>. Sulfur is the central atom, four fluorine atoms are bonded to sulfur, and sulfur also has one lone pair.<\/p>\n\n        <div class=\"ols-spec-grid\">\n          <div class=\"ols-spec-box\">\n            <strong>Bonding pairs<\/strong>\n            <span>4 bonding pairs around the central atom<\/span>\n          <\/div>\n          <div class=\"ols-spec-box\">\n            <strong>Lone pairs<\/strong>\n            <span>1 lone pair on the central atom<\/span>\n          <\/div>\n          <div class=\"ols-spec-box\">\n            <strong>Bond angles<\/strong>\n            <span>About 102&deg;, 87&deg; and 173&deg; in SF<sub>4<\/sub><\/span>\n          <\/div>\n        <\/div>\n\n        <div class=\"ols-key-box\"><p><strong>Key idea:<\/strong> four bonding pairs and one lone pair around a central atom give a SeeSaw shape when the lone pair occupies an equatorial position in a trigonal bipyramidal electron-pair arrangement.<\/p><\/div>\n      <\/article>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Quick Check: Which Species Is SeeSaw-Shaped?<\/h2>\n<p>All four species have four bonded atoms, so count the electrons around each central atom to find the SeeSaw.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-217\" class=\"h5p-iframe\" data-content-id=\"217\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"SeeSaw Shape MCQ: Four Bonded Atoms but Only One SeeSaw\"><\/iframe><\/div><\/div>\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>Why SF<sub>4<\/sub> Is SeeSaw-Shaped<\/h2>\n        <\/div>\n        <p>In SF<sub>4<\/sub>, the central sulfur atom is surrounded by four S-F bonding pairs and one lone pair. This gives five regions of negative charge around sulfur.<\/p>\n        <p>Five electron regions arrange themselves as a <strong>trigonal bipyramidal electron-pair arrangement<\/strong> to minimise repulsion. The lone pair occupies an equatorial position because this gives fewer 90&deg; lone-pair interactions than placing it in an axial position.<\/p>\n        <p>A regular trigonal bipyramid has bond angles of <strong>120&deg;<\/strong> within the equatorial plane, <strong>90&deg;<\/strong> between an axial and an equatorial position and <strong>180&deg;<\/strong> between the two axial positions. A <strong>lone pair repels more strongly<\/strong> than a bonding pair, so in SF<sub>4<\/sub> these angles close up to about <strong>102&deg;<\/strong>, about <strong>87&deg;<\/strong> and about <strong>173&deg;<\/strong>.<\/p>\n        <p>The <strong>molecular shape<\/strong> only describes the positions of the atoms. Therefore, SF<sub>4<\/sub> is described as <strong>SeeSaw-shaped<\/strong>, even though its electron-pair arrangement is trigonal bipyramidal.<\/p>\n        <div class=\"ols-key-box\"><p><strong>How to count:<\/strong> start with the <strong>outer-shell electrons<\/strong> of the central atom. Add one electron for each negative charge and take one away for each positive charge. Each single bond uses one of those electrons and each double bond uses two, but a double or triple bond still counts as <strong>one bonding region<\/strong>. Divide the electrons left over by two to get the lone pairs. In SF<sub>4<\/sub>: sulfur has <strong>6 outer-shell electrons<\/strong>, the molecule has no charge, and the four S-F single bonds use four of them. Two are left over, which is one lone pair. Four bonding regions and one lone pair give five regions, so the arrangement is trigonal bipyramidal and the shape is SeeSaw. For the ion ClF<sub>4<\/sub><sup>+<\/sup>: chlorine has 7 outer-shell electrons, the positive charge takes one away to leave 6, the four bonds use four, and the two left over are again one lone pair.<\/p><\/div>\n\n        <div class=\"ols-figure-card\">\n<div class=\"ols-figure-image\"><img decoding=\"async\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/09\/fix-27.jpg\" alt=\"Labelled SF\u2084 see-saw shape with one equatorial lone pair and 119 and 89 degree angles\"><\/div>\n<div class=\"ols-figure-caption\"><p>A SeeSaw species has four bonding regions and one lone pair around the central atom. SF4 is the standard example, with simplified exam-table angles close to 119&deg; and 89&deg;.<\/p><\/div>\n<\/div>\n      <\/article>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Quick Check: Axial or Equatorial?<\/h2>\n<p>Drag the words into place to show why a lone pair prefers an equatorial position.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-216\" class=\"h5p-iframe\" data-content-id=\"216\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"SeeSaw Shape Drag: Why the Lone Pair Goes Equatorial\"><\/iframe><\/div><\/div>\n<\/section>\n\n<!-- 3D card: sf4-seesaw (swapped 26 Sep 2026) -->\n<section class=\"ols-ssw-001\" id=\"olsSsw001\">\n<style>\n@import url('https:\/\/fonts.googleapis.com\/css2?family=Poppins:wght@300;400;500;600&display=swap');\n\n.ols-ssw-001{\n  font-family:'Poppins',system-ui,-apple-system,'Segoe UI',Roboto,Helvetica,Arial,sans-serif;\n  color:#1C244B; 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padding:5px 9px; max-width:64%;}\n  .ols-ssw-001 .ssw-badge{font-size:10.5px; padding:4px 9px;}\n  \/* on a phone the caption wraps under the top-right corner, so the readout\n     moves down to the left, above the axis guide *\/\n  .ols-ssw-001 .ssw-read{font-size:11px; padding:4px 10px; top:auto; right:auto; left:14px; bottom:108px; max-width:78%; text-align:left;}\n  .ols-ssw-001 .ssw-badge.b-shape{font-size:12px;}\n  .ols-ssw-001 .ssw-badges{max-width:70%;}\n  .ols-ssw-001 .ssw-info{padding:18px;}\n}\n@media (prefers-reduced-motion:reduce){\n  .ols-ssw-001 .ssw-seg button,.ols-ssw-001 .ssw-pill{transition:none;}\n}\n\n.ols-cc-ssw-001{\n  font-family:'Poppins',system-ui,-apple-system,'Segoe UI',Roboto,Helvetica,Arial,sans-serif;\n  margin:10px auto 0; text-align:center; font-size:11px; font-style:italic; color:#aab0c0;\n}\n.ols-cc-ssw-001 a{color:#aab0c0; text-decoration:none;}\n.ols-cc-ssw-001 a:hover{text-decoration:underline;}\n<\/style>\n\n<div class=\"ssw-head\">\n  <h2 class=\"ssw-title\">Seesaw Shape of SF<sub>4<\/sub><\/h2>\n  <p class=\"ssw-sub\">Build sulfur tetrafluoride one layer at a time, from five electron pairs in a trigonal bipyramid to a seesaw, and see why the lone pair chooses an equatorial position.<\/p>\n<\/div>\n\n<div class=\"ssw-stage\" id=\"sswStage\">\n  <canvas class=\"ssw-canvas\" id=\"sswCanvas\"><\/canvas>\n  <div class=\"ssw-overlay\" id=\"sswOverlay\"><\/div>\n  <div class=\"ssw-caption\" id=\"sswCaption\"><\/div>\n  <div class=\"ssw-hint\" id=\"sswHint\">Drag to rotate<\/div>\n  <div class=\"ssw-read hide\" id=\"sswRead\"><\/div>\n  <div class=\"ssw-badges\" id=\"sswBadges\"><\/div>\n<\/div>\n\n<div class=\"ssw-controls\">\n  <div class=\"ssw-row\">\n    <span class=\"ssw-rowlab\">Step<\/span>\n    <div class=\"ssw-seg\" role=\"group\" aria-label=\"Step\">\n      <button type=\"button\" data-step=\"1\" aria-pressed=\"true\">Electron pairs<\/button>\n      <button type=\"button\" data-step=\"2\" aria-pressed=\"false\">Bonds<\/button>\n      <button type=\"button\" data-step=\"3\" aria-pressed=\"false\">Bond angles<\/button>\n    <\/div>\n  <\/div>\n\n  <div class=\"ssw-row\">\n    <span class=\"ssw-rowlab\">View<\/span>\n    <div class=\"ssw-seg\" role=\"group\" aria-label=\"Camera view\">\n      <button type=\"button\" data-v=\"front\" aria-pressed=\"false\">Front<\/button>\n      <button type=\"button\" data-v=\"side\" aria-pressed=\"false\">Side<\/button>\n      <button type=\"button\" data-v=\"top\" aria-pressed=\"false\">Top<\/button>\n    <\/div>\n  <\/div>\n\n  <div class=\"ssw-row\">\n    <span class=\"ssw-rowlab\">Show<\/span>\n    <button type=\"button\" class=\"ssw-pill\" id=\"sswTogLp\" aria-pressed=\"true\"><i class=\"dot\"><\/i>Lone pairs<\/button>\n    <button type=\"button\" class=\"ssw-pill p-gold\" id=\"sswTogAng\" aria-pressed=\"true\"><i class=\"dot\"><\/i>Bond angles<\/button>\n    <button type=\"button\" class=\"ssw-pill\" id=\"sswTogLab\" aria-pressed=\"true\"><i class=\"dot\"><\/i>Labels<\/button>\n    <button type=\"button\" class=\"ssw-pill\" id=\"sswTogCloud\" aria-pressed=\"false\"><i class=\"dot\"><\/i>Electron-pair cloud outline<\/button>\n    <button type=\"button\" class=\"ssw-pill p-red\" id=\"sswTogWhy\" aria-pressed=\"false\"><i class=\"dot\"><\/i>Why equatorial?<\/button>\n  <\/div>\n\n  <div class=\"ssw-row\">\n    <span class=\"ssw-rowlab\">Motion<\/span>\n    <button type=\"button\" class=\"ssw-pill\" id=\"sswSpin\" aria-pressed=\"false\"><i class=\"dot\"><\/i>Rotation<\/button>\n    <button type=\"button\" class=\"ssw-pill\" id=\"sswResetV\">Reset view<\/button>\n  <\/div>\n<\/div>\n\n<div class=\"ssw-info\">\n  <h3 id=\"sswInfoTitle\"><\/h3>\n  <p id=\"sswInfoText\"><\/p>\n  <div class=\"ssw-facts\" id=\"sswFacts\"><\/div>\n  <div class=\"ssw-key\">\n    <span><i style=\"background:rgba(59,120,220,0.45)\"><\/i>Electron pair<\/span>\n    <span><i style=\"background:rgba(59,120,220,0.62)\"><\/i>Lone pair<\/span>\n    <span><i style=\"background:#484e5c\"><\/i>Sulfur, central atom<\/span>\n    <span><i style=\"background:#a9dc8e\"><\/i>Fluorine<\/span>\n    <span><i style=\"background:#8c92a0\"><\/i>Bond<\/span>\n    <span><i style=\"background:#c9961c\"><\/i>Bond angle<\/span>\n    <span><i style=\"background:#d63a3a\"><\/i>Clash at 90&deg;<\/span>\n  <\/div>\n<\/div>\n<\/section>\n\n<p class=\"ols-cc-ssw-001\">&copy; Dr. Mohammed Al-Fatah &#8211; <a href=\"https:\/\/www.onlinelearningsystem.net\" target=\"_blank\" rel=\"noopener\">onlinelearningsystem.net<\/a><\/p>\n\n<script src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/JS\/sf4-seesaw.js?v=20260926\"><\/script>\n\n      <article class=\"ols-note-card purple\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">3<\/div>\n          <h2>Electron-Pair Arrangement vs Molecular Shape<\/h2>\n        <\/div>\n        <p>The electron-pair arrangement in SF<sub>4<\/sub> is based on a <strong>trigonal bipyramidal arrangement<\/strong> because there are five electron regions around sulfur.<\/p>\n        <p>The molecular shape is different. Lone pairs are not counted as atoms when naming the shape, so the visible arrangement of the four fluorine atoms is <strong>SeeSaw-shaped<\/strong>.<\/p>\n        <div class=\"ols-rule-list\">\n          <div class=\"ols-rule-item\">\n            <h3>Five electron regions<\/h3>\n            <p>Four bonding pairs and one lone pair arrange themselves as far apart as possible around sulfur.<\/p>\n          <\/div>\n          <div class=\"ols-rule-item\">\n            <h3>Equatorial lone pair<\/h3>\n            <p>The lone pair occupies an equatorial position in the trigonal bipyramidal arrangement. This reduces the number of close 90&deg; lone-pair interactions.<\/p>\n          <\/div>\n          <div class=\"ols-rule-item\">\n            <h3>SeeSaw bonded atoms<\/h3>\n            <p>The remaining four bonding pairs form two axial bonds and two equatorial bonds, producing a SeeSaw shape.<\/p>\n          <\/div>\n        <\/div>\n      <\/article>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Quick Check: Predict a New Molecule<\/h2>\n<p>Work through the prediction for tellurium tetrachloride one step at a time.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-218\" class=\"h5p-iframe\" data-content-id=\"218\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"SeeSaw Shape Single Choice: Predicting Tellurium Tetrachloride\"><\/iframe><\/div><\/div>\n<\/section>\n\n      <article class=\"ols-note-card\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">4<\/div>\n          <h2>SeeSaw Shape Examples<\/h2>\n        <\/div>\n        <p>The SeeSaw shape is found when the central atom has four bonding pairs and one lone pair. The common exam examples include sulfur, selenium, tellurium and iodine or chlorine species with five electron regions around the central atom.<\/p>\n        <div class=\"ols-table-wrap\">\n          <table class=\"ols-table\">\n            <thead>\n              <tr>\n                <th>Species<\/th>\n                <th>Central atom<\/th>\n                <th>Electron regions<\/th>\n                <th>Shape<\/th>\n                <th>Bond angles<\/th>\n              <\/tr>\n            <\/thead>\n            <tbody>\n              <tr>\n                <td data-label=\"Species\">SF<sub>4<\/sub><\/td>\n                <td data-label=\"Central atom\">S<\/td>\n                <td data-label=\"Electron regions\">4 bonding regions, 1 lone pair<\/td>\n                <td data-label=\"Shape\">SeeSaw<\/td>\n                <td data-label=\"Bond angles\">About 102&deg;, 87&deg; and 173&deg;<\/td>\n              <\/tr>\n              <tr>\n                <td data-label=\"Species\">SeF<sub>4<\/sub><\/td>\n                <td data-label=\"Central atom\">Se<\/td>\n                <td data-label=\"Electron regions\">4 bonding regions, 1 lone pair<\/td>\n                <td data-label=\"Shape\">SeeSaw<\/td>\n                <td data-label=\"Bond angles\">Slightly less than 120&deg;, 90&deg; and 180&deg;<\/td>\n              <\/tr>\n              <tr>\n                <td data-label=\"Species\">TeF<sub>4<\/sub><\/td>\n                <td data-label=\"Central atom\">Te<\/td>\n                <td data-label=\"Electron regions\">4 bonding regions, 1 lone pair<\/td>\n                <td data-label=\"Shape\">SeeSaw<\/td>\n                <td data-label=\"Bond angles\">Slightly less than 120&deg;, 90&deg; and 180&deg;<\/td>\n              <\/tr>\n              <tr>\n                <td data-label=\"Species\">IF<sub>4<\/sub><sup>+<\/sup><\/td>\n                <td data-label=\"Central atom\">I<\/td>\n                <td data-label=\"Electron regions\">4 bonding regions, 1 lone pair<\/td>\n                <td data-label=\"Shape\">SeeSaw<\/td>\n                <td data-label=\"Bond angles\">Slightly less than 120&deg;, 90&deg; and 180&deg;<\/td>\n              <\/tr>\n              <tr>\n                <td data-label=\"Species\">ClF<sub>4<\/sub><sup>+<\/sup><\/td>\n                <td data-label=\"Central atom\">Cl<\/td>\n                <td data-label=\"Electron regions\">4 bonding regions, 1 lone pair<\/td>\n                <td data-label=\"Shape\">SeeSaw<\/td>\n                <td data-label=\"Bond angles\">Slightly less than 120&deg;, 90&deg; and 180&deg;<\/td>\n              <\/tr>\n            <\/tbody>\n          <\/table>\n        <\/div>\n      <\/article>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Quick Check: A SeeSaw with Double Bonds?<\/h2>\n<p>Count the electrons used and the regions around xenon, then choose the correct description.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-655\" class=\"h5p-iframe\" data-content-id=\"655\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"SeeSaw Shape MCQ: Counting Regions in XeO\u2082F\u2082\"><\/iframe><\/div><\/div>\n<\/section>\n\n      <article class=\"ols-note-card orange\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">5<\/div>\n          <h2>How to Explain SeeSaw Shape in an Exam<\/h2>\n        <\/div>\n        <p>A full exam explanation should connect the number of electron regions to electron-pair repulsion, then explain why the lone pair is equatorial and why the bonded atoms form a SeeSaw shape.<\/p>\n\n        <div class=\"ols-rule-list\">\n          <div class=\"ols-rule-item\">\n            <h3>1. Identify the central atom<\/h3>\n            <p>For SF<sub>4<\/sub>, the central atom is sulfur.<\/p>\n          <\/div>\n          <div class=\"ols-rule-item\">\n            <h3>2. Count bonding pairs and lone pairs<\/h3>\n            <p>Sulfur has four bonding pairs and one lone pair around it.<\/p>\n          <\/div>\n          <div class=\"ols-rule-item\">\n            <h3>3. Apply electron-pair repulsion<\/h3>\n            <p>The five electron regions arrange themselves as far apart as possible. The lone pair occupies an equatorial position to reduce repulsion.<\/p>\n          <\/div>\n          <div class=\"ols-rule-item\">\n            <h3>4. State the shape and angles<\/h3>\n            <p>The four bonded atoms form a SeeSaw shape. Start from the regular trigonal bipyramidal angles of 120&deg;, 90&deg; and 180&deg;, then state that the equatorial lone pair pushes them in. In SF<sub>4<\/sub> the equatorial F-S-F angle is about 102&deg;, the axial to equatorial angles are about 87&deg; and the axial to axial angle is about 173&deg;.<\/p>\n          <\/div>\n        <\/div>\n\n        <div class=\"ols-definition-box\">\n          <p><strong>Exam answer model:<\/strong> SF<sub>4<\/sub> has four bonding pairs and one lone pair around the central sulfur atom. The five electron regions arrange themselves as a trigonal bipyramidal electron-pair arrangement. The lone pair occupies an equatorial position to minimise repulsion. Therefore, SF<sub>4<\/sub> is SeeSaw-shaped. The lone pair repels more strongly than the bonding pairs, so the angles are reduced from 120&deg;, 90&deg; and 180&deg; to about 102&deg;, about 87&deg; and about 173&deg;.<\/p>\n        <\/div>\n      <\/article>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Quick Check: Whose Reasoning Is Right?<\/h2>\n<p>In each round, choose the one student statement that is fully correct.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-219\" class=\"h5p-iframe\" data-content-id=\"219\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"SeeSaw Shape Summary: Whose Reasoning Is Right?\"><\/iframe><\/div><\/div>\n<\/section>\n\n      <article class=\"ols-note-card soft\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">6<\/div>\n          <h2>Common Exam Points<\/h2>\n        <\/div>\n        <div class=\"ols-rule-list\">\n          <div class=\"ols-rule-item\">\n            <h3>Do not call SF<sub>4<\/sub> trigonal bipyramidal<\/h3>\n            <p>The electron-pair arrangement is trigonal bipyramidal, but the molecular shape is SeeSaw because the lone pair is not counted as an atom.<\/p>\n          <\/div>\n          <div class=\"ols-rule-item\">\n            <h3>State the lone pair is equatorial<\/h3>\n            <p>The lone pair occupies an equatorial position. This reduces repulsion compared with placing the lone pair in an axial position.<\/p>\n          <\/div>\n          <div class=\"ols-rule-item\">\n            <h3>Give angles below the ideal values<\/h3>\n            <p>Quote the trigonal bipyramidal angles of 120&deg;, 90&deg; and 180&deg;, then say that the equatorial lone pair reduces them. For SF<sub>4<\/sub>, use about 102&deg;, about 87&deg; and about 173&deg;.<\/p>\n          <\/div>\n          <div class=\"ols-rule-item\">\n            <h3>Count around the central atom only<\/h3>\n            <p>The shape is determined by the bonding pairs and lone pairs around the central atom, not by the total number of atoms in the species.<\/p>\n          <\/div>\n        <\/div>\n      <\/article>\n\n      \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 SeeSaw shape is produced when a central atom has <strong>four bonding pairs<\/strong> and <strong>one lone pair<\/strong>. The lone pair occupies an equatorial position in a trigonal bipyramidal electron-pair arrangement, leaving four bonded atoms in a SeeSaw arrangement. The lone pair repels more strongly than the bonding pairs, so the ideal angles of 120&deg;, 90&deg; and 180&deg; are reduced to about <strong>102&deg;<\/strong>, <strong>87&deg;<\/strong> and <strong>173&deg;<\/strong> in SF<sub>4<\/sub>.<\/p>\n        <div class=\"ols-key-box\"><p><strong>Memory line:<\/strong> 4 bonding pairs + 1 lone pair = SeeSaw = about 102&deg;, 87&deg; and 173&deg;.<\/p><\/div>\n      <\/article>\n\n<section class=\"ols-course-cta-covalent\" id=\"olsCourseCtaCovalent001\">\r\n  <style>\r\n    .ols-course-cta-covalent,\r\n    .ols-course-cta-covalent * {\r\n      box-sizing: border-box;\r\n    }\r\n\r\n    .ols-course-cta-covalent {\r\n      --navy: #1C244B;\r\n      --blue: #2563eb;\r\n      --body-text: #1f2937;\r\n      --grey-text: #667085;\r\n      --border: rgba(28, 36, 75, 0.14);\r\n      --shadow: 0 18px 45px rgba(28, 36, 75, 0.12);\r\n      --inner-shadow: 0 10px 26px rgba(28, 36, 75, 0.08);\r\n\r\n      width: 100%;\r\n      margin: 30px 0 24px;\r\n     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<\/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-and-shapes-of-molecules-2-2-2-ocr-a\/\" aria-label=\"Open the OCR A Level Chemistry A 2.2.2 Covalent Bonding 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\/09\/ocr-a-level-chemistry-a-2-2-2-covalent-bonding-shapes-interactive-course-banner.jpg\"\r\n            alt=\"OCR A Level Chemistry A 2.2.2 Covalent Bonding and Shapes of Molecules interactive 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            OCR H432 | 2.2.2 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-and-shapes-of-molecules-2-2-2-ocr-a\/\">\r\n            View Course\r\n          <\/a>\r\n\r\n        <\/div>\r\n\r\n        <h2>\r\n          Master Covalent Bonding and Shapes of Molecules for OCR A Level Chemistry A\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 2.2.2 Covalent Bonding and Shapes of Molecules course. The guided video lessons are ready now; the OCR A MCQ bank, teacher-marked short-answer questions and KASP spec-point report are being written, and the course opens for enrolment as soon as they are complete.\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>Recorded lessons<\/span>\n          <strong>Coming soon<\/strong>\r\n        <\/div>\r\n\r\n        <div class=\"ols-course-stat\">\r\n          <span>Video lessons<\/span>\n          <strong>Coming soon<\/strong>\r\n        <\/div>\r\n\r\n        <div class=\"ols-course-stat\">\r\n          <span>MCQ practice<\/span>\n          <strong>Coming soon<\/strong>\r\n        <\/div>\r\n\r\n        <div class=\"ols-course-stat\">\r\n          <span>SAQ practice<\/span>\n          <strong>Coming soon<\/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 the chemistry and exam technique 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 the full 2.2.2 specification 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-and-shapes-of-molecules-2-2-2-ocr-a\/\">\r\n        View Covalent Bonding and Shapes of Molecules 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\">Some ionic radii are shown.<\/p>\r\n\r\n            <table class=\"mcq-ionic-table\">\r\n              <thead>\r\n                <tr>\r\n                  <th>Ion<\/th>\r\n                  <th>Ionic radius \/ nm<\/th>\r\n                <\/tr>\r\n              <\/thead>\r\n              <tbody>\r\n                <tr><td>Na<sup>+<\/sup><\/td><td>0.102<\/td><\/tr>\r\n                <tr><td>K<sup>+<\/sup><\/td><td>0.138<\/td><\/tr>\r\n                <tr><td>F<sup>\u2212<\/sup><\/td><td>0.133<\/td><\/tr>\r\n                <tr><td>Cl<sup>\u2212<\/sup><\/td><td>0.180<\/td><\/tr>\r\n              <\/tbody>\r\n            <\/table>\r\n\r\n            <p class=\"mcq-question-main\">Which compound has the strongest ionic bonding?<\/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\">sodium chloride<\/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\">potassium chloride<\/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\">sodium fluoride<\/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\">potassium fluoride<\/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; Melting temperature depends on the strength of metallic bonding.<br>\r\n              Explain why the metallic bonding in magnesium is much stronger than that in sodium.\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\" 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the ions can get closer together.\\n\"+\r\n\"\u2022 Smaller ions \u2192 stronger electrostatic attraction \u2192 stronger ionic lattice.\\n\"+\r\n\"\u2022 Na\u207a (0.102 nm) is smaller than K\u207a (0.138 nm).\\n\"+\r\n\"\u2022 F\u207b (0.133 nm) is smaller than Cl\u207b (0.180 nm).\\n\\n\"+\r\n\"Therefore, the strongest ionic bonding occurs in the compound formed by the smallest cation and the smallest anion \u2192 sodium fluoride (NaF).\\n\\n\"+\r\n\"The correct answer is: sodium fluoride\";\r\n\r\nconst mcqIntroScreen=document.getElementById(\"mcqIntroScreen\");\r\nconst mcqIntroTitleText=document.getElementById(\"mcqIntroTitleText\");\r\nconst mcqIntroTitleCursor=document.getElementById(\"mcqIntroTitleCursor\");\r\nconst mcqScreen=document.getElementById(\"mcqScreen\");\r\nconst mcqWrongOption=document.getElementById(\"mcqWrongOption\");\r\nconst mcqSubmitButton=document.getElementById(\"mcqSubmitButton\");\r\nconst 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because it has more atoms packed together and melts at a higher temperature than sodium.\";\r\nconst saqTeacherFeedbackText=\r\n\"Comment:\\n\"+\r\n\"This answer is not correct. Melting temperature is a result of bonding strength, not the cause of it.\\n\\n\"+\r\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\"+\r\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\"+\r\n\"Next time, include:\\n\"+\r\n\"\u2022 Ion charge: magnesium forms Mg\u00b2\u207a, sodium forms Na\u207a \u2713\\n\"+\r\n\"\u2022 Delocalised electrons: magnesium provides more electrons to the sea \u2713\\n\"+\r\n\"\u2022 Charge density: smaller, more highly charged ions create stronger attraction \u2713\\n\\n\"+\r\n\"You were close. 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The five electron regions arrange as trigonal bipyramidal, but the lone pair occupies an equatorial position, leaving two axial S-F bonds and two equatorial S-F bonds.<\/p>\n          <\/div>\n          <div class=\"ols-faq-item\">\n            <h3>What are the bond angles in a SeeSaw molecule?<\/h3>\n            <p>Start from the trigonal bipyramidal angles of 120&deg;, 90&deg; and 180&deg;. The equatorial lone pair repels more strongly than the bonding pairs, so in SF<sub>4<\/sub> the angles are reduced to about 102&deg;, about 87&deg; and about 173&deg;.<\/p>\n          <\/div>\n          <div class=\"ols-faq-item\">\n            <h3>Is SeeSaw the same as trigonal bipyramidal?<\/h3>\n            <p>No. Trigonal bipyramidal is the electron-pair arrangement for five regions of negative charge. SeeSaw is the molecular shape after the single lone pair is ignored when naming the shape.<\/p>\n          <\/div>\n          <div class=\"ols-faq-item\">\n            <h3>Why does the lone pair in SF<sub>4<\/sub> occupy an equatorial position?<\/h3>\n            <p>The lone pair occupies an equatorial position because this minimises repulsion. An equatorial lone pair has fewer 90&deg; interactions with bonding pairs than an axial lone pair.<\/p>\n          <\/div>\n        <\/div>\n      <\/section>\n\n      <section class=\"ols-related-card\">\n        <h2>Related Topics<\/h2>\n        <p>Use these related revision notes to strengthen the surrounding bonding and molecular shape ideas.<\/p>\n        <div class=\"ols-related-grid\">\n          <a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/shapes-of-molecules\/trigonal-bipyramidal\/\">Trigonal Bipyramidal<\/a>\n          <a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/shapes-of-molecules\/distorted-t\/\">Distorted T<\/a>\n          <a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/polar-molecules\/\">Polar &amp; Non-Polar Molecules<\/a>\n        <\/div>\n      <\/section>\n\n      <article class=\"ols-attribution-card\">\n        <p><strong>Copyright notice:<\/strong> This OLS revision page was written and designed by Dr. Mohammed Al-Fatah for Online Learning System. All written explanations, page structure, visual learning design and embedded teaching content are protected by copyright. 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