{"id":10537,"date":"2026-09-26T11:33:38","date_gmt":"2026-09-26T10:33:38","guid":{"rendered":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/aqa\/3-2-2-group-2-the-alkaline-earth-metals\/trends-down-groups-1-and-2\/"},"modified":"2026-09-26T13:34:18","modified_gmt":"2026-09-26T12:34:18","slug":"trends-down-groups-1-and-2","status":"publish","type":"page","link":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/aqa\/3-2-2-group-2-the-alkaline-earth-metals\/trends-down-groups-1-and-2\/","title":{"rendered":"Trends Down Groups 1 and 2"},"content":{"rendered":"\n<section class=\"ols-revision-page ols-nature-of-covalent-bonding-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      --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    .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    .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    .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-image { width: 100%; min-height: 260px; 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-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-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-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-course-cta-covalent {\n      width: 100%;\n      margin: 30px 0 24px;\n      font-family: Poppins, Arial, sans-serif;\n    }\n    .ols-course-cta-covalent, .ols-course-cta-covalent * { box-sizing: border-box; }\n    .ols-course-cta-card {\n      overflow: hidden;\n      border-radius: 30px;\n      border: 1px solid var(--border);\n      background: radial-gradient(circle at top left, rgba(37, 99, 235, 0.16), transparent 34%), linear-gradient(135deg, #ffffff 0%, #f8fbff 100%);\n      box-shadow: var(--shadow);\n      padding: 30px;\n    }\n    .ols-course-cta-top {\n      display: grid;\n      grid-template-columns: minmax(260px, 0.9fr) minmax(0, 1.1fr);\n      gap: 28px;\n      align-items: center;\n      margin-bottom: 24px;\n    }\n    .ols-course-cta-image-link { display: block; text-decoration: none; border-radius: 24px; }\n    .ols-course-cta-image {\n      width: 100%;\n      border-radius: 24px;\n      overflow: hidden;\n      border: 1px solid var(--border);\n      background: #ffffff;\n      box-shadow: var(--inner-shadow);\n      transition: transform 0.35s ease, box-shadow 0.35s ease;\n    }\n    .ols-course-cta-image img { width: 100%; height: auto; display: block; transition: transform 0.45s ease; }\n    .ols-course-cta-image-link:hover .ols-course-cta-image { transform: translateY(-8px) scale(1.015); box-shadow: 0 26px 60px rgba(28, 36, 75, 0.18), 0 0 0 1px rgba(37, 99, 235, 0.12); }\n    .ols-course-cta-image-link:hover .ols-course-cta-image img { transform: scale(1.03); }\n    .ols-course-cta-header-row { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 14px; margin-bottom: 18px; }\n    .ols-course-cta-kicker { display: inline-flex; align-items: center; padding: 8px 14px; border-radius: 999px; background: #ffffff; border: 1px solid rgba(37, 99, 235, 0.18); color: var(--blue); font-size: 14px; line-height: 1.2; font-weight: 700; box-shadow: var(--inner-shadow); }\n    .ols-course-cta-covalent h2 { margin: 0 0 14px; font-size: clamp(28px, 3.5vw, 42px); line-height: 1.15; font-weight: 800; letter-spacing: -0.03em; color: #111827; }\n    .ols-course-cta-intro { margin: 0 0 24px; color: var(--body-text); font-size: clamp(16px, 1.4vw, 18px); line-height: 1.7; font-weight: 300; }\n    .ols-course-cta-features { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px; margin: 0 0 30px; }\n    .ols-course-feature { background: rgba(255, 255, 255, 0.78); border: 1px solid var(--border); border-radius: 18px; padding: 16px 18px; }\n    .ols-course-feature h3 { margin: 0 0 6px; color: var(--navy); font-size: 18px; line-height: 1.3; font-weight: 800; }\n    .ols-course-feature p { margin: 0; color: var(--body-text); font-size: 15px; line-height: 1.6; font-weight: 300; }\n    .ols-course-cta-bottom { display: flex; justify-content: center; padding-top: 22px; border-top: 1px solid var(--border); }\n    .ols-course-button { display: inline-flex; align-items: center; justify-content: center; padding: 15px 28px; border-radius: 999px; background: var(--navy); color: #ffffff; text-decoration: none; font-size: 16px; line-height: 1.2; font-weight: 800; box-shadow: 0 12px 26px rgba(28, 36, 75, 0.18); transition: transform 0.2s ease, background 0.2s ease, box-shadow 0.2s ease; }\n    .ols-course-button:hover { transform: translateY(-2px); background: var(--blue); color: #ffffff; box-shadow: 0 16px 32px rgba(37, 99, 235, 0.24); }\n    .ols-course-button-top { flex-shrink: 0; padding: 12px 22px; font-size: 15px; }\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      .ols-course-cta-top { grid-template-columns: 1fr; }\n      .ols-course-cta-image-link { max-width: 520px; margin: 0 auto; }\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 { padding: 24px 18px; border-radius: 22px; }\n      .ols-note-title { align-items: flex-start; }\n      .ols-related-grid, .ols-course-cta-features { grid-template-columns: 1fr; }\n      .ols-figure-card { border-radius: 22px; }\n      .ols-figure-image { min-height: 210px; padding: 14px; }\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: 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border-radius: 22px; padding: 14px; margin: 18px 0 6px; }\n    .ols-figure-placeholder .ols-figure-caption p { margin: 10px 0 0; font-size: 14px; color: #667085; text-align: center; }\n\n    \/* inline checks (H5P re-flow, Sep 2026) *\/\n    .ols-h5p-card.ols-h5p-inline { padding: 26px 28px; border-left: 6px solid #7c3aed; }\n    .ols-h5p-card.ols-h5p-inline h2 { font-size: clamp(20px, 2.2vw, 27px); letter-spacing: -0.02em; }\n    .ols-h5p-card.ols-h5p-inline > p { margin: 8px 0 0; }\n    .ols-h5p-card.ols-h5p-inline .ols-h5p-frame { margin-top: 16px; padding: 14px; border-radius: 20px; }\n    .ols-h5p-kicker { display: inline-block; margin-bottom: 10px; padding: 5px 12px; border-radius: 999px; background: #ede9fe; color: #5b21b6; font-size: 12px; font-weight: 700; letter-spacing: 0.06em; text-transform: uppercase; }\n    .ols-h5p-card.ols-h5p-recap { border-left-color: #c9973a; background: linear-gradient(135deg, #ffffff 0%, #fff8e8 100%); }\n    .ols-h5p-recap .ols-h5p-kicker { background: #fdf0d2; color: #8a5a00; }\n    @media (max-width: 760px) { .ols-h5p-card.ols-h5p-inline { padding: 20px 16px; } }\n<\/style>\n\n  <aside class=\"ols-sidebar\">\n  <div class=\"ols-sidebar-header\">\n    <h3>Revision Notes<\/h3>\n    <p>A Level Chemistry<\/p>\n  <\/div>\n\n  <div class=\"ols-topic-group\">\n    <h4>3.2.2 Group 2<\/h4>\n\n    <ul class=\"ols-topic-list\">\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/aqa\/3-2-2-group-2-the-alkaline-earth-metals\/\">3.2.2 Overview<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/aqa\/3-2-2-group-2-the-alkaline-earth-metals\/trends-down-groups-1-and-2\/\">Trends Down Groups 1 and 2<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/aqa\/3-2-2-group-2-the-alkaline-earth-metals\/reactions-of-the-group-1-and-2-elements\/\">Reactions of the Group 1 and 2 Elements<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/aqa\/3-2-2-group-2-the-alkaline-earth-metals\/oxides-hydroxides-and-carbonates\/\">Oxides, Hydroxides and Carbonates<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/aqa\/3-2-2-group-2-the-alkaline-earth-metals\/solubility-trends-and-the-sulfate-test\/\">Solubility Trends and the Sulfate Test<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/aqa\/3-2-2-group-2-the-alkaline-earth-metals\/thermal-stability-and-flame-colours\/\">Thermal Stability and Flame Colours<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/aqa\/3-2-2-group-2-the-alkaline-earth-metals\/tests-for-ions\/\">Tests for Ions<\/a>\n      <\/li>\n    <\/ul>\n  <\/div>\n\n  <div class=\"ols-topic-group\">\n    <h4>Other Sections<\/h4>\n\n    <ul class=\"ols-topic-list\">\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/aqa\/3-1-7-oxidation-reduction-and-redox-equations\/\">3.1.7 Oxidation, Reduction and Redox Equations<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/aqa\/3-2-3-group-7-17-the-halogens\/\">3.2.3 Group 7 (17)<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/aqa\/3-1-2-amount-of-substance\/\">3.1.2 Amount of Substance<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/aqa\/3-2-1-periodicity\/\">3.2.1 Periodicity<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/aqa\/3-1-4-energetics\/\">3.1.4 Energetics<\/a>\n      <\/li>\n    <\/ul>\n  <\/div>\n<\/aside>\n\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      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<h1>Trends Down Groups 1 and 2<\/h1>\n        <p class=\"ols-page-intro\">A concise revision guide to the trends down Groups 1 and 2: electron configurations, atomic radius, first and second ionisation energies and melting points, and why reactivity increases down each group. Group 2 is the examined group; Group 1 is kept for comparison.<\/p>\n\n        <div class=\"ols-badges\">\n<div class=\"ols-badge\">Paper 1 and 3 AQA<\/div>\n<div class=\"ols-badge\">3.2.2 Group 2, the Alkaline Earth Metals<\/div>\n<div class=\"ols-badge\">7405\/1 and 7405\/3<\/div>\n<\/div>\n\n        <div class=\"ols-author\">\n\n    <img decoding=\"async\"\n      class=\"ols-author-avatar-img\"\n      src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/Author-Profile.jpeg\"\n      alt=\"Dr. Mohammed Al-Fatah\"\n    >\n\n    <div class=\"ols-author-content\">\n\n      <h2 class=\"ols-author-title\">\n        Written by:<br><span>Dr. Mohammed Al-Fatah<\/span>\n      <\/h2>\n\n      <p class=\"ols-author-description\">\n        Chemistry specialist revision notes for A Level Chemistry.\n      <\/p>\n\n      <a class=\"ols-linkedin-pill\" href=\"https:\/\/www.linkedin.com\/in\/doctormohammedfatah\/\" target=\"_blank\" rel=\"noopener noreferrer\">\n        <svg class=\"ols-linkedin-icon\" viewBox=\"0 0 24 24\" fill=\"currentColor\" aria-hidden=\"true\">\n          <path d=\"M4.98 3.5C4.98 4.88 3.86 6 2.48 6S0 4.88 0 3.5 1.12 1 2.48 1s2.5 1.12 2.5 2.5zM.5 8h4V24h-4V8zm7 0h3.8v2.2h.1c.5-.9 1.8-2.2 3.9-2.2 4.2 0 5 2.8 5 6.4V24h-4v-7.6c0-1.8 0-4.2-2.6-4.2s-3 2-3 4v7.8h-4V8z\"\/>\n        <\/svg>\n        View LinkedIn Profile\n      <\/a>\n\n    <\/div>\n\n  <\/div>\n      <\/header>\n\n      <section class=\"ols-h5p-card ols-h5p-inline ols-h5p-recap\">\n<span class=\"ols-h5p-kicker\">Before you start<\/span>\n<h2>GCSE Recap: The Alkali Metals<\/h2>\n<p>Three quick questions on what you already know about Group 1: their electron configurations, their ions and why potassium is more reactive than lithium.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-content\" data-content-id=\"863\"><\/div><\/div>\n<\/section>\n<article class=\"ols-note-card soft\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">1<\/div>\n<h2>Where This Sits in Your Specification<\/h2>\n<\/div>\n<p>AQA 3.2.2 examines Group 2 only. The Group 1 metals are kept in the tables for comparison, because the same reasoning explains both groups, but questions will be set on magnesium to barium.<\/p>\n<\/article>\n<article class=\"ols-note-card\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">2<\/div>\n<h2>Electron Configurations and the Ions Formed<\/h2>\n<\/div>\n<p>Every <strong>Group 1<\/strong> element has one electron in its outer s sub-shell (ns\u00b9) and every <strong>Group 2<\/strong> element has two (ns\u00b2). Sodium is 1s\u00b2 2s\u00b2 2p\u2076 3s\u00b9 and magnesium is 1s\u00b2 2s\u00b2 2p\u2076 3s\u00b2. Losing those outer electrons leaves the stable configuration of the noble gas before, so the metals form <strong>M\u207a<\/strong> and <strong>M\u00b2\u207a<\/strong> ions in every compound and their chemistry is a series of oxidations.<\/p>\n<p>Both groups are the <strong>s-block<\/strong>, and their reactions are alike because the same outer electrons are lost each time. The differences between the two groups come from the number of electrons lost, and the differences down each group come from how far those electrons sit from the nucleus.<\/p>\n<div class=\"ols-key-box\">\n<p><strong>Key idea:<\/strong> Group 1 loses one electron to give +1 ions; Group 2 loses two to give +2 ions. Every reaction of these metals is an oxidation of the metal.<\/p>\n<\/div>\n<\/article>\n<article class=\"ols-note-card soft\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">3<\/div>\n<h2>Atomic Radius<\/h2>\n<\/div>\n<p><strong>Atomic radius increases down each group<\/strong> because each element has one more occupied shell than the one above it. The extra inner shells also <strong>shield<\/strong> the outer electron from the nucleus, so the rise in nuclear charge does not pull the outer shell in.<\/p>\n<div class=\"ols-table-wrap\">\n<table class=\"ols-table\">\n<thead>\n<tr><th>Element<\/th><th>Atomic radius \/ pm<\/th><th>Element<\/th><th>Atomic radius \/ pm<\/th><\/tr>\n<\/thead>\n<tbody>\n<tr><td><strong>Li<\/strong><\/td><td>152<\/td><td>Be<\/td><td>112<\/td><\/tr>\n<tr><td><strong>Na<\/strong><\/td><td>186<\/td><td>Mg<\/td><td>160<\/td><\/tr>\n<tr><td><strong>K<\/strong><\/td><td>227<\/td><td>Ca<\/td><td>197<\/td><\/tr>\n<tr><td><strong>Rb<\/strong><\/td><td>248<\/td><td>Sr<\/td><td>215<\/td><\/tr>\n<tr><td><strong>Cs<\/strong><\/td><td>265<\/td><td>Ba<\/td><td>222<\/td><\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<!-- 3D card: atomic-radii (reused from 7978, 26 Sep 2026) -->\n<section class=\"ols-rad-001\" id=\"olsRad001\">\n<style>\n@import url('https:\/\/fonts.googleapis.com\/css2?family=Poppins:wght@300;400;500;600&display=swap');\n\n.ols-rad-001{\n  font-family:'Poppins',system-ui,-apple-system,'Segoe UI',Roboto,Helvetica,Arial,sans-serif;\n  color:#1C244B; 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font-size:11.5px; color:#7d8399; font-weight:400; margin-bottom:3px;}\n.ols-rad-001 .rad-fact strong{display:block; font-size:15px; font-weight:600; color:#1C244B;}\n\n.ols-rad-001 .rad-key{\n  margin-top:16px; display:flex; gap:20px; flex-wrap:wrap;\n  font-size:12.5px; font-weight:400; color:#5a6180;\n}\n.ols-rad-001 .rad-key i{\n  display:inline-block; width:13px; height:13px; border-radius:3px;\n  margin-right:7px; vertical-align:-2px; border:1px solid rgba(28,36,75,0.18);\n}\n\n@media (max-width:760px){\n  .ols-rad-001{padding:26px; border-radius:22px;}\n  .ols-rad-001 h2.rad-title{font-size:20.5px;}\n  .ols-rad-001 p.rad-sub{font-size:13.5px;}\n  .ols-rad-001 .rad-stage{height:400px;}\n  .ols-rad-001 .rad-rowlab{min-width:100%;}\n  .ols-rad-001 .rad-seg button{padding:9px 12px; font-size:12.5px;}\n  .ols-rad-001 .rad-caption{font-size:10.5px; padding:5px 9px; max-width:68%;}\n  .ols-rad-001 .rad-info{padding:18px;}\n}\n@media (prefers-reduced-motion:reduce){\n  .ols-rad-001 .rad-seg button,.ols-rad-001 .rad-pill{transition:none;}\n}\n\n.ols-cc-rad-001{\n  font-family:'Poppins',system-ui,-apple-system,'Segoe UI',Roboto,Helvetica,Arial,sans-serif;\n  margin:10px auto 0; text-align:center; font-size:11px; font-style:italic; color:#aab0c0;\n}\n.ols-cc-rad-001 a{color:#aab0c0; text-decoration:none;}\n.ols-cc-rad-001 a:hover{text-decoration:underline;}\n<\/style>\n\n<div class=\"rad-head\">\n  <h2 class=\"rad-title\">Atomic and Ionic Radii Across Period 3 and Down Group 1<\/h2>\n  <p class=\"rad-sub\">Every sphere is drawn to scale against the 0.1 nm ruler, so the sizes can be compared directly. Drag to rotate, scroll or pinch to zoom.<\/p>\n<\/div>\n\n<div class=\"rad-stage\" id=\"radStage\">\n  <canvas class=\"rad-canvas\" id=\"radCanvas\"><\/canvas>\n  <div class=\"rad-caption\" id=\"radCaption\"><\/div>\n  <div class=\"rad-hint\" id=\"radHint\">Drag to rotate<\/div>\n<\/div>\n\n<div class=\"rad-controls\">\n  <div class=\"rad-row\">\n    <span class=\"rad-rowlab\">View<\/span>\n    <div class=\"rad-seg\" role=\"group\" aria-label=\"View\">\n      <button type=\"button\" data-v=\"p3\" aria-pressed=\"true\">Period 3<\/button>\n      <button type=\"button\" data-v=\"iso\" aria-pressed=\"false\">Isoelectronic ions<\/button>\n      <button type=\"button\" data-v=\"g1\" aria-pressed=\"false\">Down Group 1<\/button>\n    <\/div>\n  <\/div>\n\n  <div class=\"rad-row\">\n    <span class=\"rad-rowlab\">Show<\/span>\n    <button type=\"button\" class=\"rad-pill\" id=\"radTogIon\" aria-pressed=\"false\"><i class=\"dot\"><\/i>Show ions<\/button>\n    <button type=\"button\" class=\"rad-pill\" id=\"radTogLab\" aria-pressed=\"true\"><i class=\"dot\"><\/i>Labels<\/button>\n    <button type=\"button\" class=\"rad-pill\" id=\"radTogNuc\" aria-pressed=\"false\"><i class=\"dot\"><\/i>Nucleus<\/button>\n  <\/div>\n\n  <div class=\"rad-row\">\n    <span class=\"rad-rowlab\">Animate<\/span>\n    <button type=\"button\" class=\"rad-pill act\" id=\"radPlay\">Shrink with nuclear charge<\/button>\n    <button type=\"button\" class=\"rad-pill\" id=\"radResetA\">Reset animation<\/button>\n  <\/div>\n\n  <div class=\"rad-row\">\n    <span class=\"rad-rowlab\">Motion<\/span>\n    <button type=\"button\" class=\"rad-pill\" id=\"radSpin\" aria-pressed=\"false\"><i class=\"dot\"><\/i>Rotation<\/button>\n    <button type=\"button\" class=\"rad-pill\" id=\"radResetV\">Reset view<\/button>\n  <\/div>\n<\/div>\n\n<div class=\"rad-info\">\n  <h3 id=\"radInfoTitle\"><\/h3>\n  <p id=\"radInfoText\"><\/p>\n  <div class=\"rad-facts\" id=\"radFacts\"><\/div>\n  <div class=\"rad-key\" id=\"radKey\"><\/div>\n<\/div>\n<\/section>\n\n<p class=\"ols-cc-rad-001\">&copy; Dr. Mohammed Al-Fatah &#8211; <a href=\"https:\/\/www.onlinelearningsystem.net\" target=\"_blank\" rel=\"noopener\">onlinelearningsystem.net<\/a><\/p>\n\n<script src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/JS\/atomic-radii.js\"><\/script>\n<div class=\"ols-key-box\">\n<p><strong>Exam wording:<\/strong> &#8220;More shells&#8221; and &#8220;more shielding&#8221; are both needed. A larger atom is one whose outer electrons are in a higher energy level, further from the nucleus.<\/p>\n<\/div>\n<\/article>\n<article class=\"ols-note-card purple\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">4<\/div>\n<h2>First and Second Ionisation Energies<\/h2>\n<\/div>\n<p><strong>First ionisation energy<\/strong> decreases down each group. The outer electron is further from the nucleus and shielded by more inner shells, so the attraction holding it is weaker and less energy is needed to remove it. The increase in nuclear charge is outweighed by the extra distance and shielding.<\/p>\n<div class=\"ols-table-wrap\">\n<table class=\"ols-table\">\n<thead>\n<tr><th>Element<\/th><th>1st IE \/ kJ mol\u207b\u00b9<\/th><th>Element<\/th><th>1st IE \/ kJ mol\u207b\u00b9<\/th><th>2nd IE \/ kJ mol\u207b\u00b9<\/th><\/tr>\n<\/thead>\n<tbody>\n<tr><td><strong>Li<\/strong><\/td><td>520<\/td><td>Be<\/td><td>900<\/td><td>1757<\/td><\/tr>\n<tr><td><strong>Na<\/strong><\/td><td>496<\/td><td>Mg<\/td><td>738<\/td><td>1451<\/td><\/tr>\n<tr><td><strong>K<\/strong><\/td><td>419<\/td><td>Ca<\/td><td>590<\/td><td>1145<\/td><\/tr>\n<tr><td><strong>Rb<\/strong><\/td><td>403<\/td><td>Sr<\/td><td>550<\/td><td>1064<\/td><\/tr>\n<tr><td><strong>Cs<\/strong><\/td><td>376<\/td><td>Ba<\/td><td>503<\/td><td>965<\/td><\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>For Group 2 the <strong>second ionisation energy<\/strong> matters too, because both outer electrons are lost. It is larger than the first, because the second electron is removed from a positive ion, but it follows the same downward trend for the same reasons. The sum of the first two ionisation energies is what decides how easily a Group 2 metal forms its 2+ ion.<\/p>\n<div class=\"ols-zoom-card\">\n<div class=\"ols-zoom-card-image\">\n<a class=\"ols-lightbox-link\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/09\/redox-groups-trends-groups-1-and-2-graph.png\" aria-label=\"Open image full screen\">\n<img decoding=\"async\" class=\"ols-zoomable-img ols-lightbox-target\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/09\/redox-groups-trends-groups-1-and-2-graph.png\" alt=\"Graphs of first ionisation energy and atomic radius down Groups 1 and 2\">\n<\/a>\n<\/div>\n<div class=\"ols-zoom-card-caption\"><p>Both groups show the same pattern: ionisation energy falls and atomic radius rises down the group, because each step adds a shell.<\/p><\/div>\n<\/div>\n<div class=\"ols-key-box\">\n<p><strong>Common mistake:<\/strong> Saying the outer electron is &#8220;less attracted because there are more electrons&#8221;. The reason is distance and shielding; the number of electrons on its own is not an explanation.<\/p>\n<\/div>\n<\/article>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Check: Explaining the Ionisation Energy Trend<\/h2>\n<p>Choose the complete explanation for a Group 2 data set and identify the flawed reasons in others.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-864\" class=\"h5p-iframe\" data-content-id=\"864\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Redox and Groups MCQ: Explaining the Ionisation Energy Trend\"><\/iframe><\/div><\/div>\n<\/section>\n<article class=\"ols-note-card\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">5<\/div>\n<h2>Melting Points<\/h2>\n<\/div>\n<p>The s-block metals are held together by <strong>metallic bonding<\/strong>: positive ions in a sea of delocalised electrons. Down each group the ions get larger, so the delocalised electrons are further from the nuclei and the attraction between them is weaker. <strong>Melting points therefore generally fall down the group.<\/strong> Group 1 shows a smooth fall (lithium 181 \u00b0C, sodium 98 \u00b0C, potassium 63 \u00b0C, rubidium 39 \u00b0C, caesium 28 \u00b0C). Group 2 falls overall (beryllium 1287 \u00b0C, barium 727 \u00b0C) but not smoothly, because magnesium adopts a different crystal structure from the metals below it.<\/p>\n<p>Group 2 metals melt at much higher temperatures than their Group 1 neighbours because each ion contributes two electrons to the sea and carries a 2+ charge, so the metallic bonding is much stronger.<\/p>\n<div class=\"ols-key-box\">\n<p><strong>Exam focus:<\/strong> Explain metallic melting points in terms of the charge on the ion, the size of the ion and the number of delocalised electrons per ion. Never mention covalent bonds or intermolecular forces for a metal.<\/p>\n<\/div>\n<\/article>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Check: Metallic Bonding Down a Group<\/h2>\n<p>Rank and explain melting points for metals from a data set that is not the one printed above.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-content\" data-content-id=\"865\"><\/div><\/div>\n<\/section>\n<article class=\"ols-note-card soft\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">6<\/div>\n<h2>Why Reactivity Increases Down the Group<\/h2>\n<\/div>\n<p>Every reaction of these metals starts with the loss of the outer electrons, so <strong>reactivity increases down the group as ionisation energy falls<\/strong>. Potassium reacts more violently with water than lithium because its outer electron is further from the nucleus, more shielded and more easily lost. Barium reacts with cold water where magnesium barely does, for the same reason.<\/p>\n<p>This is a trend in the ease of forming the ion, not in the stability of the compounds formed. Once formed, Mg\u00b2\u207a and Ba\u00b2\u207a compounds are all stable ionic solids.<\/p>\n<div class=\"ols-key-box\">\n<p><strong>Exam sentence:<\/strong> Reactivity increases down Group 2 because the outer electrons are further from the nucleus and more shielded, so the first and second ionisation energies decrease and the electrons are lost more easily.<\/p>\n<\/div>\n<\/article>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Check: Predicting Reactivity<\/h2>\n<p>Apply the ionisation energy argument to predict and explain the behaviour of an s-block metal you have not been given data for.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-866\" class=\"h5p-iframe\" data-content-id=\"866\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Redox and Groups True or False: Predicting Reactivity\"><\/iframe><\/div><\/div>\n<\/section>\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<h3>Explain the trend in first ionisation energy down Group 2<\/h3><p>Atomic radius increases and shielding increases, so the outer electron is less strongly attracted to the nucleus and less energy is needed to remove it, even though the nuclear charge increases.<\/p>\n<h3>Explain why calcium is more reactive than magnesium<\/h3><p>The outer electrons of calcium are further from the nucleus and more shielded, so the first and second ionisation energies are lower and the electrons are lost more easily.<\/p>\n<h3>Explain the trend in melting point<\/h3><p>Larger ions with the same charge and the same number of delocalised electrons give weaker metallic bonding.<\/p>\n<h3>Do not say<\/h3><p>&#8220;The atom is bigger so it is more reactive&#8221; without mentioning ionisation energy; &#8220;more electrons means more shielding&#8221; as the whole answer.<\/p>\n<\/article>\n<section class=\"ols-faq-card\">\n<h2>FAQs<\/h2>\n<p>Use these quick answers to check the Group 2 trends.<\/p>\n\n<div class=\"ols-faq-list\">\n<div class=\"ols-faq-item\">\n<h3>Why does atomic radius increase down the group?<\/h3>\n<p>Each element has one more occupied shell than the one above it, so the outer electrons are further from the nucleus.<\/p>\n<\/div>\n\n<div class=\"ols-faq-item\">\n<h3>Why does first ionisation energy decrease down the group?<\/h3>\n<p>The outer electron is further from the nucleus and shielded by more inner shells, so it is less strongly attracted and easier to remove, even though the nuclear charge is larger.<\/p>\n<\/div>\n\n<div class=\"ols-faq-item\">\n<h3>Why do Group 2 metals have higher melting points than Group 1 metals?<\/h3>\n<p>Each Group 2 ion is 2+ and gives two delocalised electrons, so the metallic bonding is much stronger.<\/p>\n<\/div>\n\n<div class=\"ols-faq-item\">\n<h3>Why is barium more reactive than magnesium?<\/h3>\n<p>Its outer electrons are further from the nucleus and more shielded, so its first and second ionisation energies are lower and the electrons are lost more easily.<\/p>\n<\/div>\n\n<div class=\"ols-faq-item\">\n<h3>Why is the second ionisation energy of magnesium larger than the first?<\/h3>\n<p>The second electron is removed from a positive ion, so it is held more strongly by the same nuclear charge.<\/p>\n<\/div>\n<\/div>\n<\/section>\n<section class=\"ols-related-card\">\n<h2>Related 3.2.2 Group 2 Pages<\/h2>\n<p>Use these pages to connect the ideas across 3.2.2 Group 2 and the rest of the course.<\/p>\n<div class=\"ols-related-grid\">\n<a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/aqa\/3-2-2-group-2-the-alkaline-earth-metals\/reactions-of-the-group-1-and-2-elements\/\">Reactions of the Group 1 and 2 Elements<\/a>\n<a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/aqa\/3-2-2-group-2-the-alkaline-earth-metals\/oxides-hydroxides-and-carbonates\/\">Oxides, Hydroxides and Carbonates<\/a>\n<a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/aqa\/3-2-2-group-2-the-alkaline-earth-metals\/solubility-trends-and-the-sulfate-test\/\">Solubility Trends and the Sulfate Test<\/a>\n<a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/aqa\/3-2-2-group-2-the-alkaline-earth-metals\/thermal-stability-and-flame-colours\/\">Thermal Stability and Flame Colours<\/a>\n<a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/aqa\/3-2-2-group-2-the-alkaline-earth-metals\/tests-for-ions\/\">Tests for Ions<\/a>\n<a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/aqa\/3-2-2-group-2-the-alkaline-earth-metals\/\">3.2.2 Group 2 Overview<\/a>\n<\/div>\n<\/section>\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      <div class=\"ols-image-lightbox\" id=\"olsImageLightboxNatureCovalentBonding9ch0\" 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-nature-of-covalent-bonding-9ch0-page\");\n          if (!page) { return; }\n          var lightbox = page.querySelector(\"#olsImageLightboxNatureCovalentBonding9ch0\");\n          if (!lightbox) { return; }\n          var lightboxImage = lightbox.querySelector(\".ols-image-lightbox-img\");\n    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