{"id":4573,"date":"2026-05-30T06:09:13","date_gmt":"2026-05-30T05:09:13","guid":{"rendered":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/polar-molecules\/"},"modified":"2026-06-01T09:56:12","modified_gmt":"2026-06-01T08:56:12","slug":"polar-molecules","status":"publish","type":"page","link":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/polar-molecules\/","title":{"rendered":"Polar Molecules"},"content":{"rendered":"\n<section class=\"ols-revision-page ols-polar-nonpolar-molecules-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, 0.14);\n      --shadow: 0 18px 45px rgba(28, 36, 75, 0.10);\n      --inner-shadow: 0 10px 26px rgba(28, 36, 75, 0.08);\n      font-family: Poppins, Arial, sans-serif;\n      color: var(--navy);\n      background: #ffffff;\n    }\n\n    .ols-revision-page * { box-sizing: border-box; }\n\n    .ols-main { min-width: 0; max-width: 970px; }\n    .ols-breadcrumbs { display: flex; flex-wrap: wrap; gap: 8px; margin: 10px 0 22px; font-size: 15px; color: var(--grey-text); }\n    .ols-breadcrumbs a, .ols-breadcrumbs span { color: var(--grey-text); text-decoration: none; font-weight: 600; }\n    .ols-breadcrumbs a:hover { color: var(--blue); text-decoration: underline; text-underline-offset: 3px; }\n\n    .ols-title-card, .ols-note-card, .ols-h5p-card, .ols-related-card, .ols-faq-card { background: #ffffff; border: 1px solid var(--border); border-radius: 28px; box-shadow: var(--shadow); padding: 34px; margin-bottom: 24px; overflow: hidden; }\n    .ols-title-card { background: linear-gradient(135deg, #ffffff 0%, #f8fbff 100%); }\n    .ols-title-card h1 { margin: 0 0 18px; font-size: clamp(36px, 5vw, 58px); line-height: 1.08; font-weight: 800; letter-spacing: -0.04em; color: #111827; }\n    .ols-page-intro { font-size: 19px; line-height: 1.7; font-weight: 300; color: var(--body-text); margin: 0 0 22px; }\n    .ols-badges { display: flex; flex-direction: column; align-items: flex-start; gap: 12px; margin-bottom: 22px; }\n    .ols-badge { display: inline-flex; align-items: center; padding: 9px 14px; border-radius: 999px; background: #ffffff; border: 1px solid var(--border); font-size: 15px; font-weight: 600; color: var(--navy); }\n\n    .ols-author { display: flex; align-items: center; gap: 20px; padding: 28px; border-radius: 28px; background: linear-gradient(135deg, #ffffff 0%, #f8fbff 100%); border: 1px solid rgba(28,36,75,0.12); box-shadow: 0 18px 45px rgba(28,36,75,0.10); margin-top: 22px; }\n    .ols-author-avatar-img { width: 92px; height: 92px; border-radius: 50%; object-fit: cover; object-position: center; flex-shrink: 0; border: 4px solid #ffffff; box-shadow: 0 14px 32px rgba(28,36,75,0.18), 0 0 0 1px rgba(28,36,75,0.10); transition: transform 0.25s ease, box-shadow 0.25s ease; }\n    .ols-author:hover .ols-author-avatar-img { transform: scale(1.04); box-shadow: 0 20px 42px rgba(28,36,75,0.22), 0 0 0 1px rgba(28,36,75,0.10); }\n    .ols-author-content { min-width: 0; }\n    .ols-author-title { margin: 0 0 4px; font-size: clamp(24px,3vw,34px); line-height: 1.15; font-weight: 700; color: var(--navy); letter-spacing: -0.03em; }\n    .ols-author-description { margin: 0; font-size: 17px; line-height: 1.7; font-weight: 300; color: var(--grey-text); }\n    .ols-linkedin-pill { display: inline-flex; align-items: center; justify-content: center; gap: 10px; margin-top: 16px; padding: 11px 18px; border-radius: 999px; background: linear-gradient(135deg,#0A66C2,#004182); color: #ffffff; text-decoration: none; font-size: 14px; line-height: 1; font-weight: 700; letter-spacing: 0.01em; box-shadow: 0 10px 22px rgba(10,102,194,0.24); position: relative; overflow: hidden; transition: transform 0.22s ease, box-shadow 0.22s ease; }\n    .ols-linkedin-pill::before { content: \"\"; position: absolute; top: 0; left: -120%; width: 100%; height: 100%; background: linear-gradient(120deg, rgba(255,255,255,0) 0%, rgba(255,255,255,0.28) 50%, rgba(255,255,255,0) 100%); transition: left 0.7s ease; }\n    .ols-linkedin-pill:hover { transform: translateY(-3px) scale(1.03); box-shadow: 0 16px 34px rgba(10,102,194,0.34), 0 0 0 6px rgba(10,102,194,0.10); color: #ffffff; }\n    .ols-linkedin-pill:hover::before { left: 120%; }\n    .ols-linkedin-icon { width: 18px; height: 18px; display: block; flex-shrink: 0; }\n\n    .ols-note-card.soft { background: linear-gradient(135deg, #ffffff 0%, var(--soft-red) 100%); }\n    .ols-note-card.purple { background: linear-gradient(135deg, #ffffff 0%, var(--soft-purple) 100%); }\n    .ols-note-card.orange { background: linear-gradient(135deg, #ffffff 0%, var(--soft-orange) 100%); }\n    .ols-note-title { display: flex; align-items: center; gap: 14px; margin-bottom: 20px; }\n    .ols-note-icon { width: 52px; height: 52px; border-radius: 16px; background: var(--navy); color: #ffffff; display: grid; place-items: center; font-size: 24px; font-weight: 800; flex-shrink: 0; }\n    .ols-note-title h2, .ols-h5p-card h2, .ols-related-card h2, .ols-faq-card h2 { margin: 0; font-size: clamp(28px, 3.5vw, 42px); line-height: 1.15; font-weight: 800; color: #111827; letter-spacing: -0.03em; }\n    .ols-h5p-card h2, .ols-related-card h2, .ols-faq-card h2 { margin-bottom: 14px; }\n    .ols-note-card p, .ols-note-card li { font-size: clamp(15px, 1.25vw, 17px); line-height: 1.65; font-weight: 300; color: var(--body-text); }\n    .ols-h5p-card p, .ols-related-card p, .ols-faq-card p { font-size: clamp(15px, 1.3vw, 18px); line-height: 1.65; font-weight: 300; color: var(--body-text); }\n    .ols-note-card strong, .ols-h5p-card strong, .ols-related-card strong, .ols-faq-card strong { font-weight: 700; color: var(--navy); }\n    .ols-note-card ul, .ols-note-card ol { margin: 0; padding-left: 22px; }\n\n    .ols-key-box { margin-top: 20px; background: var(--soft-green); border: 1px solid rgba(63, 143, 70, 0.25); border-radius: 20px; padding: 18px 20px; }\n    .ols-key-box p { margin: 0; font-weight: 400; color: var(--navy); }\n    .ols-definition-box { background: linear-gradient(135deg, #ffffff, var(--soft-purple)); border: 2px dashed rgba(122, 62, 157, 0.35); border-radius: 24px; padding: 22px 24px; margin-top: 22px; }\n    .ols-definition-box p { margin: 0; color: var(--navy); font-weight: 400; }\n\n    .ols-rule-list { display: grid; gap: 14px; margin-top: 18px; }\n    .ols-rule-item { background: #ffffff; border: 1px solid var(--border); border-left: 5px solid var(--blue); border-radius: 18px; padding: 18px; box-shadow: var(--inner-shadow); }\n    .ols-rule-item h3 { margin: 0 0 8px; font-size: 20px; line-height: 1.25; color: var(--navy); }\n    .ols-rule-item p { margin: 0; font-size: 15px; line-height: 1.6; }\n\n    .ols-figure-card { margin: 26px auto 4px; border: 1px solid var(--border); border-radius: 26px; overflow: hidden; background: #ffffff; box-shadow: var(--inner-shadow); max-width: 100%; }\n    .ols-figure-card.medium { max-width: 820px; }\n    .ols-figure-card.compact { max-width: 700px; }\n    .ols-figure-card.wide { max-width: 940px; }\n    .ols-figure-card.slim { max-width: 600px; }\n    .ols-figure-image { width: 100%; min-height: 240px; display: flex; align-items: center; justify-content: center; background: #ffffff; padding: 20px; }\n    .ols-figure-image img { max-width: 100%; height: auto; display: block; }\n    .ols-figure-card.slim .ols-figure-image { min-height: 170px; }\n    .ols-figure-caption { padding: 18px 24px 22px; background: linear-gradient(135deg, #ffffff, #f8fbff); border-top: 1px solid var(--border); }\n    .ols-figure-caption p { margin: 0; color: #5f6b85; font-size: clamp(15px, 1.3vw, 17px); line-height: 1.6; font-weight: 300; font-style: italic; }\n    .ols-zoom-card, .ols-zoom-card * { box-sizing: border-box; }\n    .ols-zoom-card { display: block !important; margin: 26px auto 34px !important; border: 1px solid rgba(28, 36, 75, 0.14) !important; border-radius: 26px !important; background: #ffffff !important; box-shadow: 0 18px 45px rgba(28, 36, 75, 0.10) !important; overflow: visible !important; position: relative !important; z-index: 1 !important; isolation: isolate !important; }\n    .ols-zoom-card.medium { max-width: 820px; }\n    .ols-zoom-card.compact { max-width: 700px; }\n    .ols-zoom-card.wide { max-width: 940px; }\n    .ols-zoom-card.slim { max-width: 600px; }\n    .ols-zoom-card:hover { z-index: 50 !important; }\n    .ols-zoom-card-image { display: flex !important; align-items: center !important; justify-content: center !important; width: 100% !important; min-height: 240px !important; padding: 20px !important; background: #ffffff !important; overflow: visible !important; border-top-left-radius: 26px !important; border-top-right-radius: 26px !important; position: relative !important; z-index: 2 !important; }\n    .ols-zoom-card img.ols-zoomable-img { display: block !important; max-width: 100% !important; height: auto !important; border-radius: 18px !important; cursor: zoom-in !important; pointer-events: auto !important; user-select: none !important; -webkit-user-drag: none !important; transform: translateZ(0) scale(1) !important; transform-origin: center center !important; transition: transform 0.32s ease, box-shadow 0.32s ease, filter 0.32s ease !important; position: relative !important; z-index: 2 !important; }\n    @media (hover: hover) and (pointer: fine) { .ols-zoom-card img.ols-zoomable-img:hover { transform: translateZ(0) scale(1.35) !important; box-shadow: 0 28px 70px rgba(28, 36, 75, 0.34) !important; filter: saturate(1.02) contrast(1.01) !important; z-index: 100 !important; } }\n    .ols-zoom-card-caption { padding: 18px 22px 20px !important; background: linear-gradient(135deg, #ffffff, #f8fbff) !important; border-bottom-left-radius: 26px !important; border-bottom-right-radius: 26px !important; position: relative !important; z-index: 1 !important; }\n    .ols-zoom-card-caption p { margin: 0 !important; color: #5f6b85 !important; font-size: 15px !important; line-height: 1.65 !important; font-weight: 300 !important; font-style: italic !important; font-family: Poppins, Arial, sans-serif !important; }\n    .ols-image-lightbox { position: fixed; inset: 0; z-index: 999999; display: none; align-items: center; justify-content: center; padding: 34px; background: rgba(10, 15, 35, 0.86); backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); }\n    .ols-image-lightbox.is-open { display: flex; }\n    .ols-image-lightbox-inner { position: relative; width: min(96vw, 1500px); max-height: 92vh; display: flex; align-items: center; justify-content: center; }\n    .ols-image-lightbox-img { display: block; max-width: 100%; max-height: 92vh; height: auto; width: auto; border-radius: 22px; background: #ffffff; box-shadow: 0 32px 90px rgba(0, 0, 0, 0.45); object-fit: contain; }\n    .ols-image-lightbox-close { position: absolute; top: -18px; right: -18px; width: 46px; height: 46px; border: 0; border-radius: 50%; background: #ffffff; color: var(--navy); font-family: Poppins, Arial, sans-serif; font-size: 28px; line-height: 1; font-weight: 700; cursor: pointer; box-shadow: 0 16px 34px rgba(0, 0, 0, 0.28); display: flex; align-items: center; justify-content: center; transition: transform 0.2s ease, background 0.2s ease, color 0.2s ease; }\n    .ols-image-lightbox-close:hover { transform: scale(1.08); background: var(--blue); color: #ffffff; }\n    @media (max-width: 760px) { .ols-zoom-card { border-radius: 22px !important; overflow: hidden !important; } .ols-zoom-card-image { min-height: auto !important; padding: 12px !important; overflow: hidden !important; border-top-left-radius: 22px !important; border-top-right-radius: 22px !important; } .ols-zoom-card img.ols-zoomable-img, .ols-zoom-card img.ols-zoomable-img:hover { transform: none !important; box-shadow: none !important; } .ols-zoom-card-caption { border-bottom-left-radius: 22px !important; border-bottom-right-radius: 22px !important; } .ols-image-lightbox { padding: 16px; } .ols-image-lightbox-inner { width: 100%; max-height: 88vh; } .ols-image-lightbox-img { max-height: 88vh; border-radius: 16px; } .ols-image-lightbox-close { top: 10px; right: 10px; width: 42px; height: 42px; font-size: 26px; } }\n\n\n    .ols-molecule-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; align-items: stretch; margin-top: 24px; }\n    .ols-molecule-grid .ols-figure-card { margin: 0; }\n    .ols-molecule-grid .ols-figure-image { min-height: 220px; padding: 18px; }\n\n    .ols-table-wrap { overflow: hidden; border-radius: 22px; border: 1px solid var(--border); background: #ffffff; margin-top: 18px; }\n    .ols-table { width: 100%; border-collapse: collapse; table-layout: fixed; }\n    .ols-table th { background: var(--navy); color: #ffffff; padding: 16px; text-align: left; font-size: clamp(14px, 1.2vw, 17px); font-weight: 600; overflow-wrap: anywhere; }\n    .ols-table td { padding: 16px; border-bottom: 1px solid var(--border); font-size: clamp(14px, 1.15vw, 16px); line-height: 1.45; color: var(--body-text); vertical-align: top; overflow-wrap: anywhere; }\n    .ols-table tr:last-child td { border-bottom: none; }\n\n    .ols-h5p-card { background: linear-gradient(135deg, #ffffff 0%, #f7f0ff 100%); }\n    .ols-h5p-frame { margin-top: 22px; padding: 18px; border-radius: 24px; background: #ffffff; border: 1px solid var(--border); box-shadow: inset 0 0 0 1px rgba(28, 36, 75, 0.03); }\n\n    .ols-infographic-full { width: 100%; max-width: 100%; margin: 6px 0 30px; overflow: hidden; }\n    .ols-infographic-title { margin: 0 0 18px; font-size: clamp(28px, 3.5vw, 42px); line-height: 1.15; font-weight: 800; color: #111827; letter-spacing: -0.03em; }\n    .ols-infographic-full-frame { width: 100%; max-width: 100%; border-radius: 22px; overflow: hidden; box-shadow: 0 18px 42px rgba(28, 36, 75, 0.13); background: #ffffff; border: 1px solid var(--border); padding: 0; }\n    .ols-infographic-full-frame a { display: block; }\n    .ols-infographic-full-frame img { width: 100%; max-width: 100%; height: auto; display: block; object-fit: contain; transition: transform 0.3s ease; }\n    .ols-infographic-full-frame a:hover img { transform: scale(1.015); }\n\n    .ols-course-cta { background: linear-gradient(135deg, var(--navy), #0f4fa8); border-radius: 30px; padding: 36px; color: #ffffff; box-shadow: var(--shadow); text-align: center; margin: 30px 0 24px; }\n    .ols-course-cta h2 { margin: 0 0 12px; font-size: clamp(30px, 4vw, 46px); line-height: 1.15; font-weight: 800; color: #ffffff; text-align: center; }\n    .ols-course-cta p { margin: 0 auto 24px; max-width: 740px; font-size: 20px; line-height: 1.6; font-weight: 300; text-align: center; color: #ffffff; }\n    .ols-course-cta .ols-cta-button { display: inline-flex; align-items: center; justify-content: center; padding: 14px 26px; border-radius: 999px; background: #ffffff; color: var(--navy); text-decoration: none; font-weight: 700; transition: transform 0.2s ease, box-shadow 0.2s ease; }\n    .ols-course-cta .ols-cta-button:hover { transform: translateY(-2px); box-shadow: 0 12px 24px rgba(0,0,0,0.18); }\n\n    .ols-faq-list { display: grid; gap: 14px; margin-top: 18px; }\n    .ols-faq-item { background: #ffffff; border: 1px solid var(--border); border-radius: 18px; padding: 18px 20px; box-shadow: var(--inner-shadow); }\n    .ols-faq-item h3 { margin: 0 0 8px; font-size: 20px; line-height: 1.3; color: var(--navy); }\n    .ols-faq-item p { margin: 0; font-size: 16px; line-height: 1.65; color: var(--body-text); }\n\n    .ols-related-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; margin-top: 18px; }\n    .ols-related-item { border: 1px solid var(--border); border-radius: 18px; padding: 18px; background: #ffffff; color: var(--navy); text-decoration: none; font-weight: 600; line-height: 1.5; transition: transform 0.2s ease, box-shadow 0.2s ease; }\n    .ols-related-item:hover { transform: translateY(-2px); box-shadow: 0 10px 22px rgba(28, 36, 75, 0.08); }\n\n    .ols-attribution-card {\n      background: linear-gradient(135deg, #ffffff, #f8fbff);\n      border: 1px solid rgba(28, 36, 75, 0.14);\n      border-radius: 28px;\n      box-shadow: 0 18px 45px rgba(28, 36, 75, 0.10);\n      padding: 34px;\n      margin-bottom: 24px;\n      overflow: hidden;\n      font-family: Poppins, Arial, sans-serif;\n      box-sizing: border-box;\n    }\n    .ols-attribution-card, .ols-attribution-card * { box-sizing: border-box; }\n    .ols-attribution-card p { margin: 0; font-size: 14px; line-height: 1.65; font-weight: 300; color: #667085; }\n    .ols-attribution-card strong { font-weight: 700; color: #1C244B; }\n\n    @media (max-width: 1050px) {\n      .ols-main { max-width: none; }\n      .ols-related-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }\n    }\n\n    @media (max-width: 760px) {\n      .ols-title-card, .ols-note-card, .ols-h5p-card, .ols-related-card, .ols-faq-card, .ols-attribution-card, .ols-course-cta { padding: 24px 18px; border-radius: 22px; }\n      .ols-note-title { align-items: flex-start; }\n      .ols-related-grid, .ols-molecule-grid { grid-template-columns: 1fr; }\n      .ols-figure-card { border-radius: 22px; }\n      .ols-figure-image { min-height: 190px; padding: 12px; }\n      .ols-figure-caption { padding: 16px; }\n      .ols-table-wrap { border: none; background: transparent; }\n      .ols-table, .ols-table thead, .ols-table tbody, .ols-table th, .ols-table td, .ols-table tr { display: block; width: 100%; }\n      .ols-table { border-collapse: separate; border-spacing: 0; }\n      .ols-table thead { display: none; }\n      .ols-table tr { margin-bottom: 14px; border: 1px solid var(--border); border-radius: 18px; 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\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        <span>Non-Polar &amp; Polar Molecules<\/span>\n      <\/nav>\n\n      <header class=\"ols-title-card\">\n        <h1>Non-Polar &amp; Polar Molecules<\/h1>\n        <p class=\"ols-page-intro\">A concise revision guide to molecular polarity, bond dipole cancellation, symmetrical molecules, lone pair effects and the charged rod experiment used to test polar liquids.<\/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          <img decoding=\"async\"\n            class=\"ols-author-avatar-img\"\n            src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/Author-Profile.jpeg\"\n            alt=\"Dr. Mohammed Al-Fatah\"\n          >\n\n          <div class=\"ols-author-content\">\n            <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\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          <\/div>\n        <\/div>\n      <\/header>\n\n      <article class=\"ols-note-card soft\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">1<\/div>\n          <h2>What Makes a Molecule Polar?<\/h2>\n        <\/div>\n\n        <p>A <strong>polar molecule<\/strong> has an <strong>overall dipole<\/strong>. This means there is a permanent separation of charge across the whole molecule.<\/p>\n        <p>Molecular polarity depends on two linked ideas: the polarity of the individual bonds and the <strong>3D shape<\/strong> of the molecule.<\/p>\n        <p>A molecule can contain polar bonds but still be non-polar overall if the bond dipoles cancel out.<\/p>\n\n        <div class=\"ols-definition-box\">\n          <p><strong>Definition:<\/strong> A polar molecule has an uneven distribution of electron density, giving one side of the molecule a partial negative character and another side a partial positive character.<\/p>\n        <\/div>\n\n        <div class=\"ols-key-box\">\n          <p><strong>Key idea:<\/strong> Do not decide molecular polarity from bond polarity alone. Always check the 3D shape and whether the bond dipoles cancel.<\/p>\n        <\/div>\n\n        <div class=\"ols-figure-card ols-zoom-card wide\">\n          <div class=\"ols-figure-image ols-zoom-card-image\">\n            <img decoding=\"async\" class=\"ols-zoomable-img ols-lightbox-target\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/Polarity-comparison-of-molecular-structures.webp\" alt=\"Comparison of non-polar and polar molecular structures with bond dipoles\">\n          <\/div>\n          <div class=\"ols-figure-caption ols-zoom-card-caption\">\n            <p>Overall polarity depends on whether the bond dipoles cancel in the 3D structure.<\/p>\n          <\/div>\n        <\/div>\n      <\/article>\n\n      <article class=\"ols-note-card\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">2<\/div>\n          <h2>When Polar Bonds Cancel Out<\/h2>\n        <\/div>\n\n        <p>Some molecules contain polar covalent bonds but are <strong>non-polar molecules<\/strong> overall.<\/p>\n        <p>This happens when the molecule is symmetrical, the same atoms or groups are arranged evenly around the central atom, and there are no lone pairs causing an uneven shape.<\/p>\n        <p>The bond dipoles point in different directions and cancel, leaving <strong>no overall dipole moment<\/strong>.<\/p>\n\n        <div class=\"ols-rule-list\">\n          <div class=\"ols-rule-item\">\n            <h3>Symmetry cancels equal dipoles<\/h3>\n            <p>If equal polar bonds are arranged symmetrically in 3D, the molecule has no net dipole.<\/p>\n          <\/div>\n          <div class=\"ols-rule-item\">\n            <h3>Shape matters<\/h3>\n            <p>Dipoles cancel in three dimensions, not just on a flat paper diagram.<\/p>\n          <\/div>\n        <\/div>\n\n        <div class=\"ols-molecule-grid\">\n          <div class=\"ols-figure-card ols-zoom-card\">\n            <div class=\"ols-figure-image ols-zoom-card-image\">\n              <img decoding=\"async\" class=\"ols-zoomable-img ols-lightbox-target\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/CCl4.webp\" alt=\"Tetrahedral carbon tetrachloride molecule with symmetrical bond dipoles\">\n            <\/div>\n            <div class=\"ols-figure-caption ols-zoom-card-caption\">\n              <p>CCl<sub>4<\/sub> has four polar C-Cl bonds, but the tetrahedral arrangement makes the dipoles cancel.<\/p>\n            <\/div>\n          <\/div>\n\n          <div class=\"ols-figure-card ols-zoom-card\">\n            <div class=\"ols-figure-image ols-zoom-card-image\">\n              <img decoding=\"async\" class=\"ols-zoomable-img ols-lightbox-target\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/BF3.webp\" alt=\"Trigonal planar boron trifluoride molecule with symmetrical bond dipoles\">\n            <\/div>\n            <div class=\"ols-figure-caption ols-zoom-card-caption\">\n              <p>BF<sub>3<\/sub> is trigonal planar and symmetrical, so the B-F bond dipoles cancel.<\/p>\n            <\/div>\n          <\/div>\n        <\/div>\n      <\/article>\n\n      <section id=\"ols-ccl4-polarisation-card\" class=\"ols-ccl4-card\">\n  <style>\n    #ols-ccl4-polarisation-card {\n      --ols-navy: #1C244B;\n      --ols-gold: #c9973a;\n      --ols-blue: #1f7ae0;\n      --ols-red: #c81e1e;\n      --ols-soft-blue: #eef6ff;\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-ccl4-polarisation-card * {\n      box-sizing: border-box;\n    }\n\n    #ols-ccl4-polarisation-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-ccl4-polarisation-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-ccl4-polarisation-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-ccl4-polarisation-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-ccl4-polarisation-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-ccl4-polarisation-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-ccl4-polarisation-card #olsCCl4Viewer {\n      width: 100%;\n      height: 100%;\n      display: block;\n    }\n\n    #ols-ccl4-polarisation-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-ccl4-polarisation-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-ccl4-polarisation-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-ccl4-polarisation-card .ols-btn:hover {\n      transform: translateY(-2px);\n      box-shadow: 0 8px 20px rgba(28, 36, 75, 0.12);\n    }\n\n    #ols-ccl4-polarisation-card .ols-btn.is-active {\n      background: var(--ols-navy);\n      color: #ffffff;\n      border-color: var(--ols-navy);\n    }\n\n    #ols-ccl4-polarisation-card .ols-btn.ols-blue {\n      background: var(--ols-blue);\n      color: #ffffff;\n      border-color: var(--ols-blue);\n    }\n\n    #ols-ccl4-polarisation-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-ccl4-polarisation-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-ccl4-polarisation-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-ccl4-polarisation-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-ccl4-polarisation-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-ccl4-polarisation-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-ccl4-polarisation-card .ols-key-message strong {\n      font-weight: 700;\n      color: var(--ols-navy);\n    }\n\n    @media (max-width: 820px) {\n      #ols-ccl4-polarisation-card .ols-viewer-wrap {\n        height: 470px;\n      }\n\n      #ols-ccl4-polarisation-card .ols-explanation-grid {\n        grid-template-columns: 1fr;\n      }\n\n      #ols-ccl4-polarisation-card .ols-viewer-badge {\n        top: 12px;\n        right: 12px;\n        font-size: 12px;\n      }\n    }\n\n    @media (max-width: 520px) {\n      #ols-ccl4-polarisation-card .ols-model-header,\n      #ols-ccl4-polarisation-card .ols-explanation {\n        padding-left: 18px;\n        padding-right: 18px;\n      }\n\n      #ols-ccl4-polarisation-card .ols-viewer-wrap {\n        height: 420px;\n      }\n\n      #ols-ccl4-polarisation-card .ols-controls {\n        padding: 14px;\n      }\n\n      #ols-ccl4-polarisation-card .ols-btn {\n        width: 100%;\n      }\n    }\n  <\/style>\n\n  <div class=\"ols-model-card\">\n    <div class=\"ols-model-header\">\n      <div class=\"ols-pill\">3D dot-cloud model<\/div>\n      <h2 class=\"ols-model-title\">Bond dipole cancellation in CCl\u2084<\/h2>\n      <p class=\"ols-model-subtitle\">\n        A 3D model showing four identical polar C-Cl bonds arranged symmetrically around carbon. Each C-Cl bond is polar, but the tetrahedral shape makes the bond dipoles cancel, so CCl\u2084 is non-polar overall.\n      <\/p>\n    <\/div>\n\n    <div class=\"ols-viewer-wrap\">\n      <div id=\"olsCCl4Viewer\"><\/div>\n      <div class=\"ols-viewer-badge\">Drag to rotate \u2022 Scroll to zoom<\/div>\n    <\/div>\n\n    <div class=\"ols-controls\">\n      <button type=\"button\" class=\"ols-btn is-active\" id=\"olsCCl4RotateBtn\">Pause rotation<\/button>\n      <button type=\"button\" class=\"ols-btn ols-blue\" id=\"olsCCl4PolarBtn\">Show normal cloud<\/button>\n      <button type=\"button\" class=\"ols-btn\" id=\"olsCCl4DipoleBtn\">Hide bond arrows<\/button>\n      <button type=\"button\" class=\"ols-btn\" id=\"olsCCl4ResetBtn\">Reset view<\/button>\n    <\/div>\n\n    <div class=\"ols-explanation\">\n      <p class=\"ols-key-message\">\n        <strong>Key idea:<\/strong> CCl\u2084 contains four polar C-Cl bonds, but the molecule is tetrahedral and symmetrical. The equal bond dipoles point in different directions and cancel each other. Therefore, there is <strong>no overall dipole<\/strong>, so <strong>CCl\u2084 is non-polar<\/strong>.\n      <\/p>\n\n      <div class=\"ols-explanation-grid\">\n        <div class=\"ols-info-box\">\n          <strong>Polar C-Cl bonds<\/strong>\n          <span>Chlorine is more electronegative than carbon, so each C-Cl bond has electron density pulled towards chlorine.<\/span>\n        <\/div>\n\n        <div class=\"ols-info-box\">\n          <strong>Symmetrical tetrahedron<\/strong>\n          <span>The four chlorine atoms are arranged evenly around the central carbon atom in a tetrahedral shape.<\/span>\n        <\/div>\n\n        <div class=\"ols-info-box\">\n          <strong>Overall result<\/strong>\n          <span>The equal bond dipoles cancel in three dimensions, leaving no net dipole across the whole molecule.<\/span>\n        <\/div>\n      <\/div>\n    <\/div>\n  <\/div>\n\n  <script src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/JS\/CCl4.js\"><\/script>\n<\/section>\n\n      <article class=\"ols-note-card orange\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">3<\/div>\n          <h2>When a Molecule Is Polar Overall<\/h2>\n        <\/div>\n\n        <p>A molecule becomes polar when the individual bond dipoles do <strong>not<\/strong> cancel out.<\/p>\n        <p>This commonly happens when the molecule is not symmetrical, or when lone pairs create an uneven distribution of electron density.<\/p>\n        <p>If the polar bonds point roughly towards the same side of a molecule, there will be a net dipole across the molecule.<\/p>\n\n        <div class=\"ols-key-box\">\n          <p><strong>Exam focus:<\/strong> Explain both parts: the molecule has polar bonds, and the shape means the dipoles do not cancel.<\/p>\n        <\/div>\n      <\/article>\n\n      <section id=\"ols-chcl3-polarisation-card\" class=\"ols-chcl3-card\">\n  <style>\n    #ols-chcl3-polarisation-card {\n      --ols-navy: #1C244B;\n      --ols-gold: #c9973a;\n      --ols-blue: #1f7ae0;\n      --ols-red: #c81e1e;\n      --ols-soft-blue: #eef6ff;\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-chcl3-polarisation-card * {\n      box-sizing: border-box;\n    }\n\n    #ols-chcl3-polarisation-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-chcl3-polarisation-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-chcl3-polarisation-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-chcl3-polarisation-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-chcl3-polarisation-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-chcl3-polarisation-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-chcl3-polarisation-card #olsCHCl3Viewer {\n      width: 100%;\n      height: 100%;\n      display: block;\n    }\n\n    #ols-chcl3-polarisation-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-chcl3-polarisation-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-chcl3-polarisation-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-chcl3-polarisation-card .ols-btn:hover {\n      transform: translateY(-2px);\n      box-shadow: 0 8px 20px rgba(28, 36, 75, 0.12);\n    }\n\n    #ols-chcl3-polarisation-card .ols-btn.is-active {\n      background: var(--ols-navy);\n      color: #ffffff;\n      border-color: var(--ols-navy);\n    }\n\n    #ols-chcl3-polarisation-card .ols-btn.ols-blue {\n      background: var(--ols-blue);\n      color: #ffffff;\n      border-color: var(--ols-blue);\n    }\n\n    #ols-chcl3-polarisation-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-chcl3-polarisation-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-chcl3-polarisation-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-chcl3-polarisation-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-chcl3-polarisation-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-chcl3-polarisation-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-chcl3-polarisation-card .ols-key-message strong {\n      font-weight: 700;\n      color: var(--ols-navy);\n    }\n\n    @media (max-width: 820px) {\n      #ols-chcl3-polarisation-card .ols-viewer-wrap {\n        height: 470px;\n      }\n\n      #ols-chcl3-polarisation-card .ols-explanation-grid {\n        grid-template-columns: 1fr;\n      }\n\n      #ols-chcl3-polarisation-card .ols-viewer-badge {\n        top: 12px;\n        right: 12px;\n        font-size: 12px;\n      }\n    }\n\n    @media (max-width: 520px) {\n      #ols-chcl3-polarisation-card .ols-model-header,\n      #ols-chcl3-polarisation-card .ols-explanation {\n        padding-left: 18px;\n        padding-right: 18px;\n      }\n\n      #ols-chcl3-polarisation-card .ols-viewer-wrap {\n        height: 420px;\n      }\n\n      #ols-chcl3-polarisation-card .ols-controls {\n        padding: 14px;\n      }\n\n      #ols-chcl3-polarisation-card .ols-btn {\n        width: 100%;\n      }\n    }\n  <\/style>\n\n  <div class=\"ols-model-card\">\n    <div class=\"ols-model-header\">\n      <div class=\"ols-pill\">3D dot-cloud model<\/div>\n      <h2 class=\"ols-model-title\">Polarisation in CHCl\u2083<\/h2>\n      <p class=\"ols-model-subtitle\">\n        A 3D model showing the electron cloud density pulled towards the average direction of the three chlorine atoms. The C-Cl bonds are polar and their dipoles do not cancel, so CHCl\u2083 is a polar molecule.\n      <\/p>\n    <\/div>\n\n    <div class=\"ols-viewer-wrap\">\n      <div id=\"olsCHCl3Viewer\"><\/div>\n      <div class=\"ols-viewer-badge\">Drag to rotate \u2022 Scroll to zoom<\/div>\n    <\/div>\n\n    <div class=\"ols-controls\">\n      <button type=\"button\" class=\"ols-btn is-active\" id=\"olsCHCl3RotateBtn\">Pause rotation<\/button>\n      <button type=\"button\" class=\"ols-btn ols-blue\" id=\"olsCHCl3PolarBtn\">Show normal cloud<\/button>\n      <button type=\"button\" class=\"ols-btn\" id=\"olsCHCl3DipoleBtn\">Hide dipole arrow<\/button>\n      <button type=\"button\" class=\"ols-btn\" id=\"olsCHCl3ResetBtn\">Reset view<\/button>\n    <\/div>\n\n    <div class=\"ols-explanation\">\n      <p class=\"ols-key-message\">\n        <strong>Key idea:<\/strong> CHCl\u2083 has three polar C-Cl bonds and one C-H bond arranged tetrahedrally around carbon. Because the molecule is not symmetrical, the bond dipoles do not cancel. The overall electron density is shifted towards the chlorine side, making <strong>CHCl\u2083 polar<\/strong>.\n      <\/p>\n\n      <div class=\"ols-explanation-grid\">\n        <div class=\"ols-info-box\">\n          <strong>Chlorine side<\/strong>\n          <span>Chlorine atoms are more electronegative than carbon and hydrogen, so the shared electron density is pulled towards the Cl atoms.<\/span>\n        <\/div>\n\n        <div class=\"ols-info-box\">\n          <strong>Asymmetrical tetrahedron<\/strong>\n          <span>CHCl\u2083 has three Cl atoms and one H atom, so the molecule does not have equal electron pull in all directions.<\/span>\n        <\/div>\n\n        <div class=\"ols-info-box\">\n          <strong>Overall polarity<\/strong>\n          <span>The average pull of the three C-Cl bonds gives a net dipole towards the chlorine-rich side of the molecule.<\/span>\n        <\/div>\n      <\/div>\n    <\/div>\n  <\/div>\n\n  <script src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/JS\/CHCl3.js\"><\/script>\n<\/section>\n\n      <article class=\"ols-note-card purple\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">4<\/div>\n          <h2>Lone Pairs Can Make Polarity Trickier<\/h2>\n        <\/div>\n\n        <p>Some molecules are polar even when their bonds are weakly polar or treated as essentially non-polar at this level.<\/p>\n        <p>The reason is that lone pairs occupy regions of electron density and can make the overall electron distribution uneven.<\/p>\n        <p>PH<sub>3<\/sub> is a useful tricky example: the P-H electronegativity difference is very small, but the molecule is trigonal pyramidal with a lone pair on phosphorus, so it has a small overall dipole.<\/p>\n\n        <div class=\"ols-definition-box\">\n          <p><strong>Important distinction:<\/strong> Bond polarity is about individual bonds. Molecular polarity is about the overall electron distribution across the entire molecule.<\/p>\n        <\/div>\n      <\/article>\n\n      <section id=\"ols-ph3-polarisation-card\" class=\"ols-ph3-card\">\n  <style>\n    #ols-ph3-polarisation-card {\n      --ols-navy: #1C244B;\n      --ols-gold: #c9973a;\n      --ols-blue: #1f7ae0;\n      --ols-red: #c81e1e;\n      --ols-soft-blue: #eef6ff;\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-ph3-polarisation-card * {\n      box-sizing: border-box;\n    }\n\n    #ols-ph3-polarisation-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-ph3-polarisation-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-ph3-polarisation-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-ph3-polarisation-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-ph3-polarisation-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-ph3-polarisation-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-ph3-polarisation-card #olsPH3Viewer {\n      width: 100%;\n      height: 100%;\n      display: block;\n    }\n\n    #ols-ph3-polarisation-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-ph3-polarisation-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-ph3-polarisation-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-ph3-polarisation-card .ols-btn:hover {\n      transform: translateY(-2px);\n      box-shadow: 0 8px 20px rgba(28, 36, 75, 0.12);\n    }\n\n    #ols-ph3-polarisation-card .ols-btn.is-active {\n      background: var(--ols-navy);\n      color: #ffffff;\n      border-color: var(--ols-navy);\n    }\n\n    #ols-ph3-polarisation-card .ols-btn.ols-blue {\n      background: var(--ols-blue);\n      color: #ffffff;\n      border-color: var(--ols-blue);\n    }\n\n    #ols-ph3-polarisation-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-ph3-polarisation-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-ph3-polarisation-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-ph3-polarisation-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-ph3-polarisation-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-ph3-polarisation-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-ph3-polarisation-card .ols-key-message strong {\n      font-weight: 700;\n      color: var(--ols-navy);\n    }\n\n    @media (max-width: 820px) {\n      #ols-ph3-polarisation-card .ols-viewer-wrap {\n        height: 470px;\n      }\n\n      #ols-ph3-polarisation-card .ols-explanation-grid {\n        grid-template-columns: 1fr;\n      }\n\n      #ols-ph3-polarisation-card .ols-viewer-badge {\n        top: 12px;\n        right: 12px;\n        font-size: 12px;\n      }\n    }\n\n    @media (max-width: 520px) {\n      #ols-ph3-polarisation-card .ols-model-header,\n      #ols-ph3-polarisation-card .ols-explanation {\n        padding-left: 18px;\n        padding-right: 18px;\n      }\n\n      #ols-ph3-polarisation-card .ols-viewer-wrap {\n        height: 420px;\n      }\n\n      #ols-ph3-polarisation-card .ols-controls {\n        padding: 14px;\n      }\n\n      #ols-ph3-polarisation-card .ols-btn {\n        width: 100%;\n      }\n    }\n  <\/style>\n\n  <div class=\"ols-model-card\">\n    <div class=\"ols-model-header\">\n      <div class=\"ols-pill\">3D dot-cloud model<\/div>\n      <h2 class=\"ols-model-title\">Why PH\u2083 is polar despite non-polar P-H bonds<\/h2>\n      <p class=\"ols-model-subtitle\">\n        A tricky 3D model showing that the P-H bonds in PH\u2083 are almost non-polar, but the molecule is still polar overall because the lone pair on phosphorus creates an uneven electron distribution.\n      <\/p>\n    <\/div>\n\n    <div class=\"ols-viewer-wrap\">\n      <div id=\"olsPH3Viewer\"><\/div>\n      <div class=\"ols-viewer-badge\">Drag to rotate \u2022 Scroll to zoom<\/div>\n    <\/div>\n\n    <div class=\"ols-controls\">\n      <button type=\"button\" class=\"ols-btn is-active\" id=\"olsPH3RotateBtn\">Pause rotation<\/button>\n      <button type=\"button\" class=\"ols-btn ols-blue\" id=\"olsPH3PolarBtn\">Show normal cloud<\/button>\n      <button type=\"button\" class=\"ols-btn\" id=\"olsPH3LonePairBtn\">Hide lone pair<\/button>\n      <button type=\"button\" class=\"ols-btn\" id=\"olsPH3ResetBtn\">Reset view<\/button>\n    <\/div>\n\n    <div class=\"ols-explanation\">\n      <p class=\"ols-key-message\">\n        <strong>Key idea:<\/strong> the P-H bonds in PH\u2083 are usually treated as essentially non-polar because the electronegativity difference is very small. However, PH\u2083 is not symmetrical in electron distribution because phosphorus has a lone pair. The molecule is <strong>trigonal pyramidal<\/strong>, and the electron density is unevenly concentrated towards the lone pair region, making <strong>PH\u2083 weakly polar<\/strong>.\n      <\/p>\n\n      <div class=\"ols-explanation-grid\">\n        <div class=\"ols-info-box\">\n          <strong>P-H bonds<\/strong>\n          <span>The P-H electronegativity difference is very small, so each P-H bond is normally treated as non-polar or only very weakly polar.<\/span>\n        <\/div>\n\n        <div class=\"ols-info-box\">\n          <strong>Lone pair effect<\/strong>\n          <span>The lone pair occupies one region around phosphorus, creating an uneven distribution of electron density.<\/span>\n        <\/div>\n\n        <div class=\"ols-info-box\">\n          <strong>Overall polarity<\/strong>\n          <span>The trigonal pyramidal shape means the electron density is not evenly balanced, so PH\u2083 has a small overall dipole.<\/span>\n        <\/div>\n      <\/div>\n    <\/div>\n  <\/div>\n\n  <script src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/JS\/PH3.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 Decide if a Molecule Is Polar<\/h2>\n        <\/div>\n\n        <p>Use a step-by-step approach rather than guessing from the formula.<\/p>\n\n        <div class=\"ols-table-wrap\">\n          <table class=\"ols-table\">\n            <thead>\n              <tr>\n                <th>Step<\/th>\n                <th>What to check<\/th>\n                <th>Exam conclusion<\/th>\n              <\/tr>\n            <\/thead>\n            <tbody>\n              <tr>\n                <td data-label=\"Step\"><strong>1<\/strong><\/td>\n                <td data-label=\"What to check\">Decide whether the individual bonds are polar using electronegativity differences.<\/td>\n                <td data-label=\"Exam conclusion\">More electronegative atoms attract bonding electrons more strongly.<\/td>\n              <\/tr>\n              <tr>\n                <td data-label=\"Step\"><strong>2<\/strong><\/td>\n                <td data-label=\"What to check\">Work out the 3D shape of the molecule, including lone pairs.<\/td>\n                <td data-label=\"Exam conclusion\">The same formula drawn flat can hide the real direction of the dipoles.<\/td>\n              <\/tr>\n              <tr>\n                <td data-label=\"Step\"><strong>3<\/strong><\/td>\n                <td data-label=\"What to check\">Check whether the dipoles cancel due to symmetry.<\/td>\n                <td data-label=\"Exam conclusion\">If the dipoles cancel, the molecule is non-polar overall.<\/td>\n              <\/tr>\n              <tr>\n                <td data-label=\"Step\"><strong>4<\/strong><\/td>\n                <td data-label=\"What to check\">If the dipoles do not cancel, identify the direction of the overall dipole.<\/td>\n                <td data-label=\"Exam conclusion\">If there is a net dipole, the molecule is polar.<\/td>\n              <\/tr>\n            <\/tbody>\n          <\/table>\n        <\/div>\n      <\/article>\n\n      <article class=\"ols-note-card soft\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">6<\/div>\n          <h2>Experiment: Charged Rod and Polar Liquids<\/h2>\n        <\/div>\n\n        <p>A simple demonstration of molecular polarity uses a charged rod brought close to a thin jet of liquid flowing from a burette.<\/p>\n        <p>If the liquid is polar, its molecules contain permanent dipoles. These dipoles align in the electric field from the charged rod, causing the jet of liquid to be attracted and deflected.<\/p>\n        <p>The stronger the overall dipole in the liquid molecules, the greater the deflection of the liquid jet. Non-polar liquids show little or no significant deflection.<\/p>\n\n        <div class=\"ols-figure-card ols-zoom-card compact\">\n          <div class=\"ols-figure-image ols-zoom-card-image\">\n            <img decoding=\"async\" class=\"ols-zoomable-img ols-lightbox-target\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/experiment-of-polar-liquid.webp\" alt=\"Charged rod deflecting a thin jet of polar liquid from a burette\">\n          <\/div>\n          <div class=\"ols-figure-caption ols-zoom-card-caption\">\n            <p>A polar liquid can be attracted towards a charged rod because its molecular dipoles align with the electric field.<\/p>\n          <\/div>\n        <\/div>\n      <\/article>\n\n      <article class=\"ols-note-card\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">7<\/div>\n          <h2>Common Exam Points<\/h2>\n        <\/div>\n\n        <p>Strong answers use the words <strong>polar bonds<\/strong>, <strong>3D shape<\/strong>, <strong>symmetrical<\/strong>, <strong>dipoles cancel<\/strong> and <strong>overall dipole<\/strong> accurately.<\/p>\n\n        <div class=\"ols-rule-list\">\n          <div class=\"ols-rule-item\">\n            <h3>Do not stop at \u201cthe bonds are polar\u201d<\/h3>\n            <p>A molecule with polar bonds may still be non-polar overall if the dipoles cancel.<\/p>\n          <\/div>\n          <div class=\"ols-rule-item\">\n            <h3>Use cancellation language<\/h3>\n            <p>For CCl<sub>4<\/sub> and BF<sub>3<\/sub>, state that the bond dipoles cancel because the molecule is symmetrical.<\/p>\n          <\/div>\n          <div class=\"ols-rule-item\">\n            <h3>Mention lone pairs where relevant<\/h3>\n            <p>Lone pairs can distort the shape or make electron density uneven, so the molecule may have an overall dipole.<\/p>\n          <\/div>\n          <div class=\"ols-rule-item\">\n            <h3>Experimental deflection<\/h3>\n            <p>A polar liquid is attracted to a charged rod because permanent dipoles align with the electric field.<\/p>\n          <\/div>\n        <\/div>\n      <\/article>\n\n      <section class=\"ols-h5p-card\">\n        <h2>Check Your Understanding<\/h2>\n        <p>Use these short activities to check molecular polarity, dipole cancellation, lone pair effects and the charged rod experiment.<\/p>\n\n        <div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-220\" class=\"h5p-iframe\" data-content-id=\"220\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"T3.2.4.1 Drag: Non-Polar and Polar Molecules Key Concepts\"><\/iframe><\/div><\/div>\n        <div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-221\" class=\"h5p-iframe\" data-content-id=\"221\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"T3.2.4.2 MCQ: Why CCl4 Is Non-Polar\"><\/iframe><\/div><\/div>\n        <div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-222\" class=\"h5p-iframe\" data-content-id=\"222\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"T3.2.4.3 MCQ: Why CHCl3 Is Polar\"><\/iframe><\/div><\/div>\n        <div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-223\" class=\"h5p-iframe\" data-content-id=\"223\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"T3.2.4.4 MCQ: The Tricky Polarity of PH3\"><\/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\n        <p>Molecular polarity is decided by both bond polarity and molecular shape. Symmetrical molecules can contain polar bonds but be non-polar overall because the dipoles cancel. Unsymmetrical molecules, or molecules with lone pair effects that create uneven electron density, can be polar overall.<\/p>\n\n        <div class=\"ols-rule-list\">\n          <div class=\"ols-rule-item\">\n            <h3>Polar molecule<\/h3>\n            <p>Has an overall dipole due to uneven electron density across the molecule.<\/p>\n          <\/div>\n          <div class=\"ols-rule-item\">\n            <h3>Non-polar molecule<\/h3>\n            <p>Has no overall dipole because the bond dipoles cancel or the bonds are non-polar.<\/p>\n          <\/div>\n          <div class=\"ols-rule-item\">\n            <h3>Symmetry<\/h3>\n            <p>Equal bond dipoles arranged symmetrically cancel in three dimensions.<\/p>\n          <\/div>\n          <div class=\"ols-rule-item\">\n            <h3>Charged rod test<\/h3>\n            <p>Polar liquids are deflected because their permanent dipoles align with the charged rod.<\/p>\n          <\/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    .ols-course-cta-covalent-shapes {\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      font-family: Poppins, Arial, sans-serif;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-cta-card {\r\n      overflow: hidden;\r\n      border-radius: 30px;\r\n      border: 1px solid var(--border);\r\n      background:\r\n        radial-gradient(circle at top left, rgba(37, 99, 235, 0.16), transparent 34%),\r\n        linear-gradient(135deg, #ffffff 0%, #f8fbff 100%);\r\n      box-shadow: var(--shadow);\r\n      padding: 30px;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-cta-top {\r\n      display: grid;\r\n      grid-template-columns: minmax(260px, 0.9fr) minmax(0, 1.1fr);\r\n      gap: 28px;\r\n      align-items: center;\r\n      margin-bottom: 24px;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-cta-image-link {\r\n      display: block;\r\n      text-decoration: none;\r\n      border-radius: 24px;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-cta-image {\r\n      width: 100%;\r\n      border-radius: 24px;\r\n      overflow: hidden;\r\n      border: 1px solid var(--border);\r\n      background: #ffffff;\r\n      box-shadow: var(--inner-shadow);\r\n      transition:\r\n        transform 0.35s ease,\r\n        box-shadow 0.35s ease;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-cta-image img {\r\n      width: 100%;\r\n      height: auto;\r\n      display: block;\r\n      transition: transform 0.45s ease;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-cta-image-link:hover .ols-course-cta-image {\r\n      transform: translateY(-8px) scale(1.015);\r\n      box-shadow:\r\n        0 26px 60px rgba(28, 36, 75, 0.18),\r\n        0 0 0 1px rgba(37, 99, 235, 0.12);\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-cta-image-link:hover .ols-course-cta-image img {\r\n      transform: scale(1.03);\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-cta-header-row {\r\n      display: flex;\r\n      flex-wrap: wrap;\r\n      align-items: center;\r\n      justify-content: space-between;\r\n      gap: 14px;\r\n      margin-bottom: 18px;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-cta-kicker {\r\n      display: inline-flex;\r\n      align-items: center;\r\n      padding: 8px 14px;\r\n      border-radius: 999px;\r\n      background: #ffffff;\r\n      border: 1px solid rgba(37, 99, 235, 0.18);\r\n      color: var(--blue);\r\n      font-size: 14px;\r\n      line-height: 1.2;\r\n      font-weight: 700;\r\n      box-shadow: var(--inner-shadow);\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes h2 {\r\n      margin: 0 0 14px;\r\n      font-size: clamp(28px, 3.5vw, 42px);\r\n      line-height: 1.15;\r\n      font-weight: 800;\r\n      letter-spacing: -0.03em;\r\n      color: #111827;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-cta-intro-stats {\r\n      display: grid;\r\n      grid-template-columns: minmax(0, 1.08fr) minmax(320px, 0.92fr);\r\n      gap: 24px;\r\n      align-items: stretch;\r\n      margin: 0 0 30px;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-cta-intro {\r\n      margin: 0;\r\n      color: var(--body-text);\r\n      font-size: clamp(16px, 1.4vw, 18px);\r\n      line-height: 1.7;\r\n      font-weight: 300;\r\n      align-self: center;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-cta-stats {\r\n      display: grid;\r\n      grid-template-columns: repeat(2, minmax(0, 1fr));\r\n      gap: 14px;\r\n      margin: 0;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-stat {\r\n      background: #ffffff;\r\n      border: 1px solid var(--border);\r\n      border-radius: 18px;\r\n      padding: 16px;\r\n      box-shadow: var(--inner-shadow);\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-stat span {\r\n      display: block;\r\n      margin-bottom: 6px;\r\n      color: var(--grey-text);\r\n      font-size: 13px;\r\n      line-height: 1.35;\r\n      font-weight: 700;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-stat strong {\r\n      display: block;\r\n      color: var(--navy);\r\n      font-size: 18px;\r\n      line-height: 1.35;\r\n      font-weight: 800;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-cta-features {\r\n      display: grid;\r\n      grid-template-columns: repeat(2, minmax(0, 1fr));\r\n      gap: 14px;\r\n      margin: 0 0 30px;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-feature {\r\n      background: rgba(255, 255, 255, 0.78);\r\n      border: 1px solid var(--border);\r\n      border-radius: 18px;\r\n      padding: 16px 18px;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-feature h3 {\r\n      margin: 0 0 6px;\r\n      color: var(--navy);\r\n      font-size: 18px;\r\n      line-height: 1.3;\r\n      font-weight: 800;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-feature p {\r\n      margin: 0;\r\n      color: var(--body-text);\r\n      font-size: 15px;\r\n      line-height: 1.6;\r\n      font-weight: 300;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-animation-wrap {\r\n      position: relative;\r\n      margin: 0 0 30px;\r\n      border-radius: 0;\r\n      overflow: visible;\r\n      border: 0;\r\n      background: transparent;\r\n      box-shadow: none;\r\n      padding: 0;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-animation-title {\r\n      margin: 0 0 18px;\r\n      text-align: center;\r\n      color: var(--navy);\r\n      font-size: clamp(26px, 3.2vw, 40px);\r\n      line-height: 1.15;\r\n      font-weight: 700;\r\n      letter-spacing: -0.03em;\r\n      text-shadow: -9px 0 9px rgba(28, 36, 75, 0.10);\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-animation-frame-shell {\r\n      position: relative;\r\n      width: 100%;\r\n      height: 620px;\r\n      border-radius: 24px;\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      box-shadow: 0 24px 64px rgba(28, 36, 75, 0.18);\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-animation-frame-shell iframe {\r\n      display: block;\r\n      width: 100%;\r\n      height: 100%;\r\n      border: 0;\r\n      background: #e9efff;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-animation-start-overlay {\r\n      position: absolute;\r\n      inset: 0;\r\n      z-index: 5;\r\n      display: flex;\r\n      align-items: center;\r\n      justify-content: center;\r\n      border: 0;\r\n      cursor: pointer;\r\n      background:\r\n        radial-gradient(circle at center, rgba(255, 255, 255, 0.26), rgba(28, 36, 75, 0.28)),\r\n        url(\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/T2AB-Covalent-Bonding-Structure-Shapes-of-Molecules.jpg\");\r\n      background-size: cover;\r\n      background-position: center;\r\n      transition:\r\n        opacity 0.35s ease,\r\n        visibility 0.35s ease;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-animation-start-overlay::before {\r\n      content: \"\";\r\n      position: absolute;\r\n      inset: 0;\r\n      background: rgba(28, 36, 75, 0.30);\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-animation-start-overlay.is-hidden {\r\n      opacity: 0;\r\n      visibility: hidden;\r\n      pointer-events: none;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-animation-start-content {\r\n      position: relative;\r\n      z-index: 2;\r\n      display: grid;\r\n      justify-items: center;\r\n      gap: 16px;\r\n      padding: 24px;\r\n      text-align: center;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-animation-play-circle {\r\n      width: 96px;\r\n      height: 96px;\r\n      border-radius: 50%;\r\n      background: #ffffff;\r\n      color: var(--navy);\r\n      display: flex;\r\n      align-items: center;\r\n      justify-content: center;\r\n      box-shadow:\r\n        0 18px 40px rgba(28, 36, 75, 0.30),\r\n        0 0 0 12px rgba(255, 255, 255, 0.22);\r\n      animation: olsAnimationPlayPulse001 1.8s ease-in-out infinite;\r\n      transition:\r\n        transform 0.25s ease,\r\n        background 0.25s ease,\r\n        color 0.25s ease;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-animation-start-overlay:hover .ols-animation-play-circle {\r\n      transform: scale(1.08);\r\n      background: var(--navy);\r\n      color: #ffffff;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-animation-play-icon {\r\n      width: 0;\r\n      height: 0;\r\n      margin-left: 7px;\r\n      border-top: 18px solid transparent;\r\n      border-bottom: 18px solid transparent;\r\n      border-left: 28px solid currentColor;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-animation-start-text {\r\n      max-width: 540px;\r\n      margin: 0;\r\n      color: #ffffff;\r\n      font-size: clamp(20px, 3vw, 32px);\r\n      line-height: 1.2;\r\n      font-weight: 800;\r\n      text-shadow: 0 8px 20px rgba(0, 0, 0, 0.28);\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-animation-pause-button {\r\n      position: absolute;\r\n      left: 16px;\r\n      bottom: 16px;\r\n      z-index: 7;\r\n      display: none;\r\n      align-items: center;\r\n      justify-content: center;\r\n      min-width: 92px;\r\n      padding: 10px 16px;\r\n      border: 0;\r\n      border-radius: 999px;\r\n      background: rgba(28, 36, 75, 0.92);\r\n      color: #ffffff;\r\n      font-family: Poppins, Arial, sans-serif;\r\n      font-size: 14px;\r\n      line-height: 1.2;\r\n      font-weight: 800;\r\n      cursor: pointer;\r\n      box-shadow: 0 12px 28px rgba(28, 36, 75, 0.24);\r\n      transition:\r\n        transform 0.2s ease,\r\n        background 0.2s ease,\r\n        box-shadow 0.2s ease;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-animation-pause-button:hover {\r\n      transform: translateY(-2px);\r\n      background: var(--blue);\r\n      box-shadow: 0 16px 34px rgba(37, 99, 235, 0.28);\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-animation-pause-button.is-visible {\r\n      display: inline-flex;\r\n    }\r\n\r\n    @keyframes olsAnimationPlayPulse001 {\r\n      0% {\r\n        box-shadow:\r\n          0 18px 40px rgba(28, 36, 75, 0.30),\r\n          0 0 0 0 rgba(255, 255, 255, 0.40);\r\n      }\r\n\r\n      70% {\r\n        box-shadow:\r\n          0 18px 40px rgba(28, 36, 75, 0.30),\r\n          0 0 0 18px rgba(255, 255, 255, 0);\r\n      }\r\n\r\n      100% {\r\n        box-shadow:\r\n          0 18px 40px rgba(28, 36, 75, 0.30),\r\n          0 0 0 0 rgba(255, 255, 255, 0);\r\n      }\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-video-status {\r\n      margin: 14px 0 0;\r\n      text-align: center;\r\n      color: var(--grey-text);\r\n      font-size: 13px;\r\n      line-height: 1.5;\r\n      font-weight: 500;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-cta-bottom {\r\n      display: flex;\r\n      justify-content: center;\r\n      padding-top: 22px;\r\n      border-top: 1px solid var(--border);\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-button {\r\n      display: inline-flex;\r\n      align-items: center;\r\n      justify-content: center;\r\n      padding: 15px 28px;\r\n      border-radius: 999px;\r\n      background: var(--navy);\r\n      color: #ffffff;\r\n      text-decoration: none;\r\n      font-size: 16px;\r\n      line-height: 1.2;\r\n      font-weight: 800;\r\n      box-shadow: 0 12px 26px rgba(28, 36, 75, 0.18);\r\n      transition:\r\n        transform 0.2s ease,\r\n        background 0.2s ease,\r\n        box-shadow 0.2s ease;\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-button:hover {\r\n      transform: translateY(-2px);\r\n      background: var(--blue);\r\n      color: #ffffff;\r\n      box-shadow: 0 16px 32px rgba(37, 99, 235, 0.24);\r\n    }\r\n\r\n    .ols-course-cta-covalent-shapes .ols-course-button-top {\r\n      flex-shrink: 0;\r\n      padding: 12px 22px;\r\n      font-size: 15px;\r\n    }\r\n\r\n    @media (max-width: 900px) {\r\n      .ols-course-cta-covalent-shapes .ols-course-cta-top {\r\n        grid-template-columns: 1fr;\r\n      }\r\n\r\n      .ols-course-cta-covalent-shapes .ols-course-cta-image-link {\r\n        max-width: 520px;\r\n        margin: 0 auto;\r\n      }\r\n\r\n      .ols-course-cta-covalent-shapes .ols-course-cta-intro-stats {\r\n        grid-template-columns: 1fr;\r\n      }\r\n\r\n      .ols-course-cta-covalent-shapes .ols-animation-frame-shell {\r\n        height: 520px;\r\n      }\r\n    }\r\n\r\n    @media (max-width: 760px) {\r\n      .ols-course-cta-covalent-shapes {\r\n        margin: 26px 0 22px;\r\n      }\r\n\r\n      .ols-course-cta-covalent-shapes .ols-course-cta-card {\r\n        padding: 20px;\r\n        border-radius: 24px;\r\n      }\r\n\r\n      .ols-course-cta-covalent-shapes .ols-course-cta-header-row {\r\n        align-items: stretch;\r\n      }\r\n\r\n      .ols-course-cta-covalent-shapes .ols-course-button-top {\r\n        width: 100%;\r\n      }\r\n\r\n      .ols-course-cta-covalent-shapes .ols-course-cta-stats,\r\n      .ols-course-cta-covalent-shapes .ols-course-cta-features {\r\n        grid-template-columns: 1fr;\r\n      }\r\n\r\n      .ols-course-cta-covalent-shapes .ols-course-animation-wrap {\r\n        padding: 0;\r\n        border-radius: 0;\r\n      }\r\n\r\n      .ols-course-cta-covalent-shapes .ols-animation-frame-shell {\r\n        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            <span id=\"saqTeacherText\"><\/span><span id=\"saqTeacherCursor\" class=\"cursor saq-teacher-cursor\" style=\"display:none;\"><\/span>\r\n          <\/section>\r\n        <\/main>\r\n      <\/div>\r\n    <\/div>\r\n  <\/section>\r\n\r\n<\/div>\r\n\r\n<script>\r\n(function(){\r\n  const nativeSetTimeout=window.setTimeout.bind(window);\r\n  const nativeClearTimeout=window.clearTimeout.bind(window);\r\n  let nextTimerId=1;\r\n  let paused=false;\r\n  const timers=new Map();\r\n\r\n  function runTimer(timerId){\r\n    const timer=timers.get(timerId);\r\n\r\n    if(!timer || timer.cleared){\r\n      return;\r\n    }\r\n\r\n    timers.delete(timerId);\r\n    timer.callback();\r\n  }\r\n\r\n  window.setTimeout=function(callback,delay){\r\n    const timerId=nextTimerId++;\r\n    const safeDelay=Math.max(0,Number(delay) || 0);\r\n\r\n    const timer={\r\n      callback:callback,\r\n      delay:safeDelay,\r\n      remaining:safeDelay,\r\n      startedAt:Date.now(),\r\n      nativeId:null,\r\n      cleared:false\r\n    };\r\n\r\n    if(paused){\r\n      timer.startedAt=null;\r\n    }else{\r\n      timer.nativeId=nativeSetTimeout(function(){\r\n        runTimer(timerId);\r\n      },safeDelay);\r\n    }\r\n\r\n    timers.set(timerId,timer);\r\n    return timerId;\r\n  };\r\n\r\n  window.clearTimeout=function(timerId){\r\n    const timer=timers.get(timerId);\r\n\r\n    if(timer){\r\n      timer.cleared=true;\r\n\r\n      if(timer.nativeId!==null){\r\n        nativeClearTimeout(timer.nativeId);\r\n      }\r\n\r\n      timers.delete(timerId);\r\n      return;\r\n    }\r\n\r\n    nativeClearTimeout(timerId);\r\n  };\r\n\r\n  function pauseVideos(){\r\n    document.querySelectorAll(\"video\").forEach(function(video){\r\n      if(!video.paused && !video.ended){\r\n        video.dataset.olsWasPlaying=\"1\";\r\n        video.pause();\r\n      }\r\n    });\r\n  }\r\n\r\n  function resumeVideos(){\r\n    document.querySelectorAll(\"video\").forEach(function(video){\r\n      if(video.dataset.olsWasPlaying===\"1\"){\r\n        delete video.dataset.olsWasPlaying;\r\n\r\n        const playPromise=video.play();\r\n\r\n        if(playPromise!==undefined){\r\n          playPromise.catch(function(){});\r\n        }\r\n      }\r\n    });\r\n  }\r\n\r\n  function pauseAnimation(){\r\n    if(paused){\r\n      return \"paused\";\r\n    }\r\n\r\n    paused=true;\r\n    document.documentElement.classList.add(\"ols-animation-paused\");\r\n\r\n    timers.forEach(function(timer){\r\n      if(timer.nativeId!==null){\r\n        nativeClearTimeout(timer.nativeId);\r\n        timer.nativeId=null;\r\n      }\r\n\r\n      if(timer.startedAt!==null){\r\n        timer.remaining=Math.max(0,timer.delay-(Date.now()-timer.startedAt));\r\n        timer.startedAt=null;\r\n      }\r\n    });\r\n\r\n    pauseVideos();\r\n    return \"paused\";\r\n  }\r\n\r\n  function resumeAnimation(){\r\n    if(!paused){\r\n      return \"playing\";\r\n    }\r\n\r\n    paused=false;\r\n    document.documentElement.classList.remove(\"ols-animation-paused\");\r\n\r\n    timers.forEach(function(timer,timerId){\r\n      timer.startedAt=Date.now();\r\n      timer.delay=timer.remaining;\r\n      timer.nativeId=nativeSetTimeout(function(){\r\n        runTimer(timerId);\r\n      },timer.remaining);\r\n    });\r\n\r\n    resumeVideos();\r\n    return \"playing\";\r\n  }\r\n\r\n  window.olsToggleAnimationPause=function(){\r\n    if(paused){\r\n      return resumeAnimation();\r\n    }\r\n\r\n    return pauseAnimation();\r\n  };\r\n\r\n  window.olsPauseAnimation=pauseAnimation;\r\n  window.olsResumeAnimation=resumeAnimation;\r\n})();\r\n\r\nfunction typeWriter(target,text,speed,callback){\r\n  let i=0;\r\n\r\n  function typing(){\r\n    if(i<text.length){\r\n      const char=text.charAt(i);\r\n      target.textContent+=char;\r\n      i++;\r\n\r\n      let delay=speed;\r\n\r\n      if(char===\".\"){delay=speed*5;}\r\n      if(char===\",\"){delay=speed*2.5;}\r\n      if(char===\"\\n\"){delay=speed*4;}\r\n\r\n      setTimeout(typing,delay);\r\n    }else{\r\n      if(callback){callback();}\r\n    }\r\n  }\r\n\r\n  typing();\r\n}\r\n\r\nfunction switchScene(currentScene,nextScene,callback){\r\n  currentScene.classList.add(\"fade-out\");\r\n\r\n  setTimeout(function(){\r\n    currentScene.classList.remove(\"active\");\r\n    currentScene.classList.remove(\"fade-out\");\r\n    nextScene.classList.add(\"active\");\r\n\r\n    if(callback){callback();}\r\n  },850);\r\n}\r\n\r\nfunction fitVideoScreen(){\r\n  const baseWidth=1180;\r\n  const baseHeight=664;\r\n  const safePadding=24;\r\n  const availableWidth=window.innerWidth-safePadding;\r\n  const availableHeight=window.innerHeight-safePadding;\r\n  const scaleByWidth=availableWidth\/baseWidth;\r\n  const scaleByHeight=availableHeight\/baseHeight;\r\n  const finalScale=Math.min(scaleByWidth,scaleByHeight,1);\r\n  document.documentElement.style.setProperty(\"--ols-video-screen-scale\",finalScale.toFixed(4));\r\n}\r\n\r\nfunction fitMcqScreen(){\r\n  const baseWidth=1360;\r\n  const baseHeight=1130;\r\n  const safePadding=24;\r\n  const availableWidth=window.innerWidth-safePadding;\r\n  const availableHeight=window.innerHeight-safePadding;\r\n  const scaleByWidth=availableWidth\/baseWidth;\r\n  const scaleByHeight=availableHeight\/baseHeight;\r\n  const finalScale=Math.min(scaleByWidth,scaleByHeight,1);\r\n  document.documentElement.style.setProperty(\"--ols-mcq-screen-scale\",finalScale.toFixed(4));\r\n}\r\n\r\nfunction fitSaqScreen(){\r\n  const baseWidth=1360;\r\n  const baseHeight=965;\r\n  const safePadding=24;\r\n  const availableWidth=window.innerWidth-safePadding;\r\n  const availableHeight=window.innerHeight-safePadding;\r\n  const scaleByWidth=availableWidth\/baseWidth;\r\n  const scaleByHeight=availableHeight\/baseHeight;\r\n  const finalScale=Math.min(scaleByWidth,scaleByHeight,1);\r\n  document.documentElement.style.setProperty(\"--ols-saq-screen-scale\",finalScale.toFixed(4));\r\n}\r\n\r\nfunction fitAllScreens(){\r\n  fitVideoScreen();\r\n  fitMcqScreen();\r\n  fitSaqScreen();\r\n}\r\n\r\nwindow.addEventListener(\"resize\",fitAllScreens);\r\nwindow.addEventListener(\"orientationchange\",fitAllScreens);\r\nfitAllScreens();\r\n\r\nconst sceneVideo=document.getElementById(\"sceneVideo\");\r\nconst sceneMcq=document.getElementById(\"sceneMcq\");\r\nconst sceneSaq=document.getElementById(\"sceneSaq\");\r\n\r\nconst videoTitle=\"Online Chemistry Lessons\";\r\nconst videoTitleText=document.getElementById(\"videoTitleText\");\r\nconst videoTitleCursor=document.getElementById(\"videoTitleCursor\");\r\nconst videoTitleScreen=document.getElementById(\"videoTitleScreen\");\r\nconst videoScene=document.getElementById(\"videoScene\");\r\nconst lessonVideo=document.getElementById(\"lessonVideo\");\r\n\r\nlet videoFallbackTimer=null;\r\nlet videoSceneComplete=false;\r\n\r\nfunction playLessonVideo(){\r\n  lessonVideo.muted=true;\r\n  lessonVideo.currentTime=0;\r\n\r\n  const playPromise=lessonVideo.play();\r\n\r\n  if(playPromise!==undefined){\r\n    playPromise.catch(function(){\r\n      lessonVideo.muted=true;\r\n    });\r\n  }\r\n}\r\n\r\nfunction completeVideoScene(){\r\n  if(videoSceneComplete){return;}\r\n\r\n  videoSceneComplete=true;\r\n\r\n  if(videoFallbackTimer){\r\n    clearTimeout(videoFallbackTimer);\r\n  }\r\n\r\n  lessonVideo.pause();\r\n\r\n  setTimeout(function(){\r\n    switchScene(sceneVideo,sceneMcq,function(){\r\n      startMcqIntro();\r\n    });\r\n  },1400);\r\n}\r\n\r\nlessonVideo.addEventListener(\"ended\",function(){\r\n  lessonVideo.pause();\r\n  completeVideoScene();\r\n});\r\n\r\nfunction startVideoSection(){\r\n  fitVideoScreen();\r\n\r\n  setTimeout(function(){\r\n    typeWriter(videoTitleText,videoTitle,44,function(){\r\n      setTimeout(function(){\r\n        videoTitleCursor.style.display=\"none\";\r\n\r\n        setTimeout(function(){\r\n          videoTitleScreen.classList.add(\"hide\");\r\n\r\n          setTimeout(function(){\r\n            videoScene.classList.add(\"show\");\r\n\r\n            setTimeout(function(){\r\n              playLessonVideo();\r\n\r\n              videoFallbackTimer=setTimeout(function(){\r\n                completeVideoScene();\r\n              },45000);\r\n            },600);\r\n          },850);\r\n        },3000);\r\n      },250);\r\n    });\r\n  },700);\r\n}\r\n\r\nconst mcqIntroTitle=\"Multiple Choice Question Bank\";\r\nconst mcqSpecificFeedbackText=\"CH\u2084 is tetrahedral because it has four bonding pairs and no lone pairs around carbon.\";\r\nconst mcqGeneralFeedbackText=\r\n\"Your answer is incorrect.\\n\\n\"+\r\n\"To decide which species is not tetrahedral, count the electron pairs around the central atom and then consider the molecular shape.\\n\\n\"+\r\n\"\u2022 CH\u2084, NH\u2084\u207a and CCl\u2084 each have four bonding pairs and no lone pairs around the central atom, so they are tetrahedral.\\n\"+\r\n\"\u2022 ICl\u2084\u207b has six electron pairs around iodine: four bonding pairs and two lone pairs. The electron-pair geometry is octahedral, but the two lone pairs occupy opposite positions.\\n\"+\r\n\"\u2022 This leaves the four chlorine atoms arranged in a square plane.\\n\\n\"+\r\n\"The correct answer is: tetrachloroiodate(III) ion, ICl\u2084\u207b\";\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 mcqSpecificFeedback=document.getElementById(\"mcqSpecificFeedback\");\r\nconst mcqCrossIcon=document.getElementById(\"mcqCrossIcon\");\r\nconst mcqSpecificText=document.getElementById(\"mcqSpecificText\");\r\nconst mcqSpecificCursor=document.getElementById(\"mcqSpecificCursor\");\r\nconst mcqGeneralFeedback=document.getElementById(\"mcqGeneralFeedback\");\r\nconst mcqGeneralText=document.getElementById(\"mcqGeneralText\");\r\nconst mcqGeneralCursor=document.getElementById(\"mcqGeneralCursor\");\r\n\r\nfunction selectMcqWrongOption(){\r\n  mcqWrongOption.classList.add(\"clicking\");\r\n\r\n  setTimeout(function(){\r\n    mcqWrongOption.classList.add(\"selected\");\r\n  },220);\r\n\r\n  setTimeout(function(){\r\n    mcqWrongOption.classList.remove(\"clicking\");\r\n  },850);\r\n}\r\n\r\nfunction clickMcqSubmit(){\r\n  mcqSubmitButton.classList.add(\"clicked\");\r\n\r\n  setTimeout(function(){\r\n    mcqSubmitButton.classList.remove(\"clicked\");\r\n  },240);\r\n}\r\n\r\nfunction showMcqSpecificFeedback(){\r\n  mcqSpecificFeedback.classList.add(\"show\");\r\n\r\n  setTimeout(function(){\r\n    mcqCrossIcon.classList.add(\"show\");\r\n  },180);\r\n\r\n  setTimeout(function(){\r\n    mcqSpecificCursor.style.display=\"inline-block\";\r\n\r\n    typeWriter(mcqSpecificText,mcqSpecificFeedbackText,12,function(){\r\n      mcqSpecificCursor.style.display=\"none\";\r\n\r\n      setTimeout(function(){\r\n        showMcqGeneralFeedback();\r\n      },650);\r\n    });\r\n  },560);\r\n}\r\n\r\nfunction showMcqGeneralFeedback(){\r\n  mcqGeneralFeedback.classList.add(\"show\");\r\n\r\n  setTimeout(function(){\r\n    mcqGeneralCursor.style.display=\"inline-block\";\r\n\r\n    typeWriter(mcqGeneralText,mcqGeneralFeedbackText,8,function(){\r\n      mcqGeneralCursor.style.display=\"none\";\r\n\r\n      setTimeout(function(){\r\n        switchScene(sceneMcq,sceneSaq,function(){\r\n          startSaqIntro();\r\n        });\r\n      },2600);\r\n    });\r\n  },600);\r\n}\r\n\r\nfunction startMcqAnimation(){\r\n  fitMcqScreen();\r\n  mcqScreen.classList.add(\"show\");\r\n\r\n  setTimeout(function(){\r\n    selectMcqWrongOption();\r\n\r\n    setTimeout(function(){\r\n      clickMcqSubmit();\r\n\r\n      setTimeout(function(){\r\n        showMcqSpecificFeedback();\r\n      },620);\r\n    },1150);\r\n  },1300);\r\n}\r\n\r\nfunction startMcqIntro(){\r\n  fitMcqScreen();\r\n\r\n  setTimeout(function(){\r\n    typeWriter(mcqIntroTitleText,mcqIntroTitle,44,function(){\r\n      setTimeout(function(){\r\n        mcqIntroTitleCursor.style.display=\"none\";\r\n\r\n        setTimeout(function(){\r\n          mcqIntroScreen.classList.add(\"hide\");\r\n\r\n          setTimeout(function(){\r\n            startMcqAnimation();\r\n          },850);\r\n        },3000);\r\n      },250);\r\n    });\r\n  },700);\r\n}\r\n\r\nconst saqIntroTitle=\"Chemistry Specialist\\nMarked Exam Feedback\";\r\nconst saqStudentAnswer=\"Silicon has a higher melting point because it has stronger covalent bonds than phosphorus, so more energy is needed to melt it.\";\r\nconst saqTeacherFeedbackText=\r\n\"Comment:\\n\"+\r\n\"This answer has the right idea that strong covalent bonds are involved, but it needs to compare the structures more precisely.\\n\\n\"+\r\n\"Silicon has a giant covalent structure. 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. Melting phosphorus mainly involves overcoming weak London forces between molecules.\\n\\n\"+\r\n\"Next time, include:\\n\"+\r\n\"\u2022 Silicon: giant covalent lattice with many strong covalent bonds \u2713\\n\"+\r\n\"\u2022 Phosphorus: simple molecular P\u2084 structure \u2713\\n\"+\r\n\"\u2022 Melting phosphorus overcomes weak intermolecular forces, not covalent bonds within P\u2084 \u2713\\n\\n\"+\r\n\"This is why silicon has a much higher melting temperature than phosphorus.\";\r\n\r\nconst saqIntro=document.getElementById(\"saqIntro\");\r\nconst saqIntroTitleText=document.getElementById(\"saqIntroTitleText\");\r\nconst saqIntroTitleCursor=document.getElementById(\"saqIntroTitleCursor\");\r\nconst saqStudentText=document.getElementById(\"saqStudentText\");\r\nconst saqTeacherText=document.getElementById(\"saqTeacherText\");\r\nconst saqStudentCursor=document.getElementById(\"saqStudentCursor\");\r\nconst saqTeacherCursor=document.getElementById(\"saqTeacherCursor\");\r\nconst saqFeedbackBox=document.getElementById(\"saqTeacherFeedback\");\r\nconst saqScreen=document.getElementById(\"saqScreen\");\r\n\r\nfunction startSaqFeedbackAnimation(){\r\n  fitSaqScreen();\r\n  saqScreen.classList.add(\"show\");\r\n\r\n  setTimeout(function(){\r\n    typeWriter(saqStudentText,saqStudentAnswer,27,function(){\r\n      saqStudentCursor.style.display=\"none\";\r\n\r\n      setTimeout(function(){\r\n        saqFeedbackBox.classList.add(\"show\");\r\n        saqTeacherCursor.style.display=\"inline-block\";\r\n\r\n        typeWriter(saqTeacherText,saqTeacherFeedbackText,10,function(){\r\n          saqTeacherCursor.style.display=\"none\";\r\n        });\r\n      },650);\r\n    });\r\n  },850);\r\n}\r\n\r\nfunction startSaqIntro(){\r\n  fitSaqScreen();\r\n\r\n  setTimeout(function(){\r\n    typeWriter(saqIntroTitleText,saqIntroTitle,44,function(){\r\n      setTimeout(function(){\r\n        saqIntroTitleCursor.style.display=\"none\";\r\n\r\n        setTimeout(function(){\r\n          saqIntro.classList.add(\"hide\");\r\n\r\n          setTimeout(function(){\r\n            startSaqFeedbackAnimation();\r\n          },850);\r\n        },3000);\r\n      },250);\r\n    });\r\n  },700);\r\n}\r\n\r\nstartVideoSection();\r\n<\/script>\r\n<\/body>\r\n<\/html>\r\n  <\/template>\r\n\r\n  <script>\r\n    (function(){\r\n      var startButton = document.getElementById(\"olsCourseAnimationStart001\");\r\n      var pauseButton = document.getElementById(\"olsCourseAnimationPause001\");\r\n      var iframe = document.getElementById(\"olsCourseAnimationFrame001\");\r\n      var template = document.getElementById(\"olsCourseAnimationTemplate001\");\r\n\r\n      if (!startButton || !pauseButton || !iframe || !template) {\r\n        return;\r\n      }\r\n\r\n      startButton.addEventListener(\"click\", function(){\r\n        iframe.setAttribute(\"srcdoc\", template.innerHTML);\r\n        startButton.classList.add(\"is-hidden\");\r\n        pauseButton.classList.add(\"is-visible\");\r\n        pauseButton.textContent = \"Pause\";\r\n        pauseButton.setAttribute(\"aria-label\", \"Pause course preview animation\");\r\n      });\r\n\r\n      pauseButton.addEventListener(\"click\", function(){\r\n        if (!iframe.contentWindow || typeof iframe.contentWindow.olsToggleAnimationPause !== \"function\") {\r\n          return;\r\n        }\r\n\r\n        var state = iframe.contentWindow.olsToggleAnimationPause();\r\n\r\n        if (state === \"paused\") {\r\n          pauseButton.textContent = \"Resume\";\r\n          pauseButton.setAttribute(\"aria-label\", \"Resume course preview animation\");\r\n        } else {\r\n          pauseButton.textContent = \"Pause\";\r\n          pauseButton.setAttribute(\"aria-label\", \"Pause course preview animation\");\r\n        }\r\n      });\r\n    })();\r\n  <\/script>\r\n<\/section>\n\n\n<section class=\"ols-faq-card\">\n        <h2>FAQs<\/h2>\n        <p>Use these quick answers to check the common polarity misconceptions that appear in A Level Chemistry questions.<\/p>\n\n        <div class=\"ols-faq-list\">\n          <div class=\"ols-faq-item\">\n            <h3>Can a molecule have polar bonds but be non-polar overall?<\/h3>\n            <p>Yes. If the molecule is symmetrical, the individual bond dipoles can cancel out, leaving no overall dipole. CCl<sub>4<\/sub> and BF<sub>3<\/sub> are common examples.<\/p>\n          <\/div>\n\n          <div class=\"ols-faq-item\">\n            <h3>Why is CHCl<sub>3<\/sub> polar?<\/h3>\n            <p>CHCl<sub>3<\/sub> has three polar C-Cl bonds and one C-H bond arranged tetrahedrally. The molecule is not symmetrical, so the bond dipoles do not cancel and there is an overall dipole towards the chlorine-rich side.<\/p>\n          <\/div>\n\n          <div class=\"ols-faq-item\">\n            <h3>Why is CCl<sub>4<\/sub> non-polar even though C-Cl bonds are polar?<\/h3>\n            <p>CCl<sub>4<\/sub> is tetrahedral and symmetrical. The four equal C-Cl bond dipoles point in different directions and cancel in three dimensions.<\/p>\n          <\/div>\n\n          <div class=\"ols-faq-item\">\n            <h3>How does a charged rod show that a liquid is polar?<\/h3>\n            <p>A polar liquid contains molecules with permanent dipoles. These dipoles align with the electric field from the charged rod, so the liquid jet is attracted and bends towards the rod.<\/p>\n          <\/div>\n\n          <div class=\"ols-faq-item\">\n            <h3>Why can lone pairs affect molecular polarity?<\/h3>\n            <p>Lone pairs occupy regions of electron density and can make the electron distribution uneven. This can create an overall dipole even when the bond polarity is weak.<\/p>\n          <\/div>\n        <\/div>\n      <\/section>\n\n      <section class=\"ols-related-card\">\n        <h2>Related Topics<\/h2>\n        <p>Revise the connected bonding and structure ideas that support molecular polarity questions.<\/p>\n\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\/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\/\">Shapes of Molecules<\/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\/\">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\/dative-covalent-bonding\/\">Dative 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\/metallic-bonding\/metallic-bonding-and-structure\/\">Metallic 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\/\">Topic 2 Bonding and Structure<\/a>\n        <\/div>\n      <\/section>\n\n      <section class=\"ols-attribution-card\">\n        <p><strong>Copyright and author footprint:<\/strong> This OLS revision page was written for Online Learning System by <strong>Dr. Mohammed Al-Fatah<\/strong>. It is designed for A Level Chemistry revision and should not be copied or redistributed without permission.<\/p>\n      <\/section>\n\n\n      <div class=\"ols-image-lightbox\" id=\"olsImageLightboxPolarMolecules9ch0\" aria-hidden=\"true\" role=\"dialog\" aria-modal=\"true\" aria-label=\"Expanded revision image\">\n        <div class=\"ols-image-lightbox-inner\">\n          <button class=\"ols-image-lightbox-close\" type=\"button\" aria-label=\"Close enlarged image\">\u00d7<\/button>\n          <img decoding=\"async\" class=\"ols-image-lightbox-img\" src=\"\" alt=\"\">\n        <\/div>\n      <\/div>\n\n      <script>\n        (function(){\n          var page = document.querySelector(\".ols-polar-nonpolar-molecules-9ch0-page\");\n          if (!page) { return; }\n          var lightbox = page.querySelector(\"#olsImageLightboxPolarMolecules9ch0\");\n          if (!lightbox) { return; }\n          var lightboxImage = lightbox.querySelector(\".ols-image-lightbox-img\");\n          var closeButton = lightbox.querySelector(\".ols-image-lightbox-close\");\n          var clickableImages = page.querySelectorAll(\"img.ols-lightbox-target\");\n          function openLightbox(image) {\n            lightboxImage.src = image.currentSrc || image.src;\n            lightboxImage.alt = image.alt || \"Expanded revision image\";\n            lightbox.classList.add(\"is-open\");\n            lightbox.setAttribute(\"aria-hidden\", \"false\");\n            if (!document.body.dataset.olsPreviousOverflow) {\n              document.body.dataset.olsPreviousOverflow = document.body.style.overflow || \"default\";\n            }\n            document.body.style.overflow = \"hidden\";\n          }\n          function closeLightbox() {\n            lightbox.classList.remove(\"is-open\");\n            lightbox.setAttribute(\"aria-hidden\", \"true\");\n            lightboxImage.src = \"\";\n            if (document.body.dataset.olsPreviousOverflow) {\n              document.body.style.overflow = document.body.dataset.olsPreviousOverflow === \"default\" ? \"\" : document.body.dataset.olsPreviousOverflow;\n              delete document.body.dataset.olsPreviousOverflow;\n            }\n          }\n          clickableImages.forEach(function(image){\n            image.addEventListener(\"click\", function(event){\n              event.preventDefault();\n              event.stopPropagation();\n              openLightbox(image);\n            });\n          });\n          closeButton.addEventListener(\"click\", closeLightbox);\n          lightbox.addEventListener(\"click\", function(event){ if (event.target === lightbox) { closeLightbox(); } });\n          document.addEventListener(\"keydown\", function(event){ if (event.key === \"Escape\" && lightbox.classList.contains(\"is-open\")) { closeLightbox(); } });\n        })();\n      <\/script>\n\n      <script type=\"application\/ld+json\">\n{\n        \"@context\": \"https:\/\/schema.org\",\n        \"@graph\": [\n                {\n                        \"@type\": \"WebPage\",\n                        \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/polar-molecules\/#webpage\",\n                        \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/polar-molecules\/\",\n                        \"name\": \"Non-Polar & Polar Molecules | Edexcel A Level Chemistry Revision Notes\",\n                        \"description\": \"Edexcel A Level Chemistry revision notes on non-polar and polar molecules, molecular dipoles, dipole cancellation, symmetry, lone pair effects and the charged rod experiment.\",\n                        \"isPartOf\": {\n                                \"@type\": \"WebSite\",\n                                \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/#website\",\n                                \"name\": \"Online Learning System\",\n                                \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/\"\n                        },\n                        \"about\": [\n                                {\n                                        \"@type\": \"Thing\",\n                                        \"name\": \"Molecular polarity\"\n                                },\n                                {\n                                        \"@type\": \"Thing\",\n                                        \"name\": \"Dipole cancellation\"\n                                },\n                                {\n                                        \"@type\": \"Thing\",\n                                        \"name\": \"Polar molecules\"\n                                },\n                                {\n                                        \"@type\": \"Thing\",\n                                        \"name\": \"Non-polar molecules\"\n                                }\n                        ],\n                        \"educationalLevel\": \"A Level\",\n                        \"learningResourceType\": \"Revision notes\",\n                        \"inLanguage\": \"en-GB\"\n                },\n                {\n                        \"@type\": \"Article\",\n                        \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/polar-molecules\/#article\",\n                        \"headline\": \"Non-Polar & Polar Molecules\",\n                        \"description\": \"Revision notes explaining how molecular polarity depends on bond polarity, 3D shape, symmetry, dipole cancellation and lone pair effects.\",\n                        \"author\": {\n                                \"@type\": \"Person\",\n                                \"name\": \"Dr. Mohammed Al-Fatah\",\n                                \"url\": \"https:\/\/www.linkedin.com\/in\/doctormohammedfatah\/\"\n                        },\n                        \"publisher\": {\n                                \"@type\": \"Organization\",\n                                \"name\": \"Online Learning System\",\n                                \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/\",\n                                \"logo\": {\n                                        \"@type\": \"ImageObject\",\n                                        \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/Author-Profile.jpeg\"\n                                }\n                        },\n                        \"mainEntityOfPage\": {\n                                \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/polar-molecules\/#webpage\"\n                        }\n                },\n                {\n                        \"@type\": \"BreadcrumbList\",\n                        \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/polar-molecules\/#breadcrumb\",\n                        \"itemListElement\": [\n                                {\n                                        \"@type\": \"ListItem\",\n                                        \"position\": 1,\n                                        \"name\": \"Revision Notes\",\n                                        \"item\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/\"\n                                },\n                                {\n                                        \"@type\": \"ListItem\",\n                                        \"position\": 2,\n                                        \"name\": \"A Level Chemistry\",\n                                        \"item\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/\"\n                                },\n                                {\n                                        \"@type\": \"ListItem\",\n                                        \"position\": 3,\n                                        \"name\": \"Edexcel\",\n                                        \"item\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/\"\n                                },\n                                {\n                                        \"@type\": \"ListItem\",\n                                        \"position\": 4,\n                                        \"name\": \"Topic 2 Bonding and Structure\",\n                                        \"item\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/\"\n                                },\n                                {\n                                        \"@type\": \"ListItem\",\n                                        \"position\": 5,\n                                        \"name\": \"Non-Polar & Polar Molecules\",\n                                        \"item\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/polar-molecules\/\"\n                                }\n                        ]\n                },\n                {\n                        \"@type\": \"Course\",\n                        \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/product\/covalent-bonding-shapes-of-molecules-edexcel-t2ab\/#course\",\n                        \"name\": \"Covalent Bonding, Structure and Shapes of Molecules\",\n                        \"description\": \"A paid OLS course covering covalent bonding, structure, molecular shapes, electron-pair repulsion, bond angles, polarity and exam-style practice for Edexcel A Level Chemistry.\",\n                        \"provider\": {\n                                \"@type\": \"Organization\",\n                                \"name\": \"Online Learning System\",\n                                \"sameAs\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/\"\n                        },\n                        \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/product\/covalent-bonding-shapes-of-molecules-edexcel-t2ab\/\"\n                },\n                {\n                        \"@type\": \"FAQPage\",\n                        \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/polar-molecules\/#faq\",\n                        \"mainEntity\": [\n                                {\n                                        \"@type\": \"Question\",\n                                        \"name\": \"Can a molecule have polar bonds but be non-polar overall?\",\n                                        \"acceptedAnswer\": {\n                                                \"@type\": \"Answer\",\n                                                \"text\": \"Yes. If the molecule is symmetrical, the individual bond dipoles can cancel out, leaving no overall dipole. CCl4 and BF3 are common examples.\"\n                                        }\n                                },\n                                {\n                                        \"@type\": \"Question\",\n                                        \"name\": \"Why is CHCl3 polar?\",\n                                        \"acceptedAnswer\": {\n                                                \"@type\": \"Answer\",\n                                                \"text\": \"CHCl3 has three polar C-Cl bonds and one C-H bond arranged tetrahedrally. The molecule is not symmetrical, so the bond dipoles do not cancel and there is an overall dipole towards the chlorine-rich side.\"\n                                        }\n                                },\n                                {\n                                        \"@type\": \"Question\",\n                                        \"name\": \"Why is CCl4 non-polar even though C-Cl bonds are polar?\",\n                                        \"acceptedAnswer\": {\n                                                \"@type\": \"Answer\",\n                                                \"text\": \"CCl4 is tetrahedral and symmetrical. The four equal C-Cl bond dipoles point in different directions and cancel in three dimensions.\"\n                                        }\n                                },\n                                {\n                                        \"@type\": \"Question\",\n                                        \"name\": \"How does a charged rod show that a liquid is polar?\",\n                                        \"acceptedAnswer\": {\n                                                \"@type\": \"Answer\",\n                                                \"text\": \"A polar liquid contains molecules with permanent dipoles. These dipoles align with the electric field from the charged rod, so the liquid jet is attracted and bends towards the rod.\"\n                                        }\n                                },\n                                {\n                                        \"@type\": \"Question\",\n                                        \"name\": \"Why can lone pairs affect molecular polarity?\",\n                                        \"acceptedAnswer\": {\n                                                \"@type\": \"Answer\",\n                                                \"text\": \"Lone pairs occupy regions of electron density and can make the electron distribution uneven. This can create an overall dipole even when the bond polarity is weak.\"\n                                        }\n                                }\n                        ]\n                }\n        ]\n}\n      <\/script>\n    <\/main>\n<\/section>\n","protected":false},"excerpt":{"rendered":"<p>Revision Notes \/ A Level Chemistry \/ Edexcel \/ Topic 2 Bonding and Structure \/ Non-Polar &amp; Polar Molecules Non-Polar &amp; Polar Molecules A concise revision guide to molecular polarity, bond dipole cancellation, symmetrical molecules, lone pair effects and the charged rod experiment used to test polar liquids. Unit: Paper 1 Topic 2: Bonding and [&hellip;]<\/p>\n","protected":false},"author":12,"featured_media":0,"parent":4498,"menu_order":3,"comment_status":"closed","ping_status":"closed","template":"","meta":{"productId":0,"courseId":0,"footnotes":""},"class_list":["post-4573","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/4573","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/users\/12"}],"replies":[{"embeddable":true,"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/comments?post=4573"}],"version-history":[{"count":0,"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/4573\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/4498"}],"wp:attachment":[{"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/media?parent=4573"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}