{"id":3987,"date":"2026-05-21T04:55:21","date_gmt":"2026-05-21T03:55:21","guid":{"rendered":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/mass-spectrometry\/"},"modified":"2026-06-28T05:53:01","modified_gmt":"2026-06-28T04:53:01","slug":"mass-spectrometry","status":"publish","type":"page","link":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/mass-spectrometry\/","title":{"rendered":"Mass Spectrometry"},"content":{"rendered":"\n<section class=\"ols-revision-page ols-mass-spectrometry-landing-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-revision-layout {\n      display: grid;\n      grid-template-columns: 310px minmax(0, 1fr);\n      gap: 34px;\n      max-width: 1450px;\n      margin: 0 auto;\n      padding: 24px 20px 60px;\n    }\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n    .ols-main {\n      min-width: 0;\n      max-width: 970px;\n    }\n\n    .ols-breadcrumbs {\n      display: flex;\n      flex-wrap: wrap;\n      gap: 8px;\n      margin: 10px 0 22px;\n      font-size: 15px;\n      color: var(--grey-text);\n    }\n\n    .ols-breadcrumbs a,\n    .ols-breadcrumbs span {\n      color: var(--grey-text);\n      text-decoration: none;\n      font-weight: 600;\n    }\n\n    .ols-breadcrumbs a:hover {\n      color: var(--blue);\n      text-decoration: underline;\n      text-underline-offset: 3px;\n    }\n\n    .ols-title-card,\n    .ols-note-card,\n    .ols-related-card,\n    .ols-attribution-card {\n      background: #ffffff;\n      border: 1px solid var(--border);\n      border-radius: 28px;\n      box-shadow: var(--shadow);\n      padding: 34px;\n      margin-bottom: 24px;\n      overflow: hidden;\n    }\n\n    .ols-title-card {\n      background: linear-gradient(135deg, #ffffff 0%, #f8fbff 100%);\n    }\n\n    .ols-title-card h1 {\n      margin: 0 0 18px;\n      font-size: clamp(36px, 5vw, 58px);\n      line-height: 1.08;\n      font-weight: 800;\n      letter-spacing: -0.04em;\n      color: #111827;\n    }\n\n    .ols-page-intro {\n      font-size: 19px;\n      line-height: 1.7;\n      font-weight: 300;\n      color: var(--body-text);\n      margin: 0 0 22px;\n    }\n\n    .ols-badges {\n      display: flex;\n      flex-wrap: wrap;\n      gap: 12px;\n      margin-bottom: 22px;\n    }\n\n    .ols-badge {\n      display: inline-flex;\n      align-items: center;\n      padding: 9px 14px;\n      border-radius: 999px;\n      background: #ffffff;\n      border: 1px solid var(--border);\n      font-size: 15px;\n      font-weight: 600;\n      color: var(--navy);\n    }\n\n    .ols-author {\n      display: flex;\n      align-items: center;\n      gap: 20px;\n      padding: 28px;\n      border-radius: 28px;\n      background: linear-gradient(135deg, #ffffff 0%, #f8fbff 100%);\n      border: 1px solid rgba(28,36,75,0.12);\n      box-shadow: 0 18px 45px rgba(28,36,75,0.10);\n      margin-top: 22px;\n    }\n\n    .ols-author-avatar-img {\n      width: 92px;\n      height: 92px;\n      border-radius: 50%;\n      object-fit: cover;\n      object-position: center;\n      flex-shrink: 0;\n      border: 4px solid #ffffff;\n      box-shadow: 0 14px 32px rgba(28,36,75,0.18), 0 0 0 1px rgba(28,36,75,0.10);\n      transition: transform 0.25s ease, box-shadow 0.25s ease;\n    }\n\n    .ols-author:hover .ols-author-avatar-img {\n      transform: scale(1.04);\n      box-shadow: 0 20px 42px rgba(28,36,75,0.22), 0 0 0 1px rgba(28,36,75,0.10);\n    }\n\n    .ols-author-content { min-width: 0; }\n\n    .ols-author-title {\n      margin: 0 0 4px;\n      font-size: clamp(24px,3vw,34px);\n      line-height: 1.15;\n      font-weight: 700;\n      color: var(--navy);\n      letter-spacing: -0.03em;\n    }\n\n    .ols-author-description {\n      margin: 0;\n      font-size: 17px;\n      line-height: 1.7;\n      font-weight: 300;\n      color: var(--grey-text);\n    }\n\n    .ols-linkedin-pill {\n      display: inline-flex;\n      align-items: center;\n      justify-content: center;\n      gap: 10px;\n      margin-top: 16px;\n      padding: 11px 18px;\n      border-radius: 999px;\n      background: linear-gradient(135deg,#0A66C2,#004182);\n      color: #ffffff;\n      text-decoration: none;\n      font-size: 14px;\n      line-height: 1;\n      font-weight: 700;\n      letter-spacing: 0.01em;\n      box-shadow: 0 10px 22px rgba(10,102,194,0.24);\n      position: relative;\n      overflow: hidden;\n      transition: transform 0.22s ease, box-shadow 0.22s ease;\n    }\n\n    .ols-linkedin-pill::before {\n      content: \"\";\n      position: absolute;\n      top: 0;\n      left: -120%;\n      width: 100%;\n      height: 100%;\n      background: linear-gradient(120deg, rgba(255,255,255,0) 0%, rgba(255,255,255,0.28) 50%, rgba(255,255,255,0) 100%);\n      transition: left 0.7s ease;\n    }\n\n    .ols-linkedin-pill:hover {\n      transform: translateY(-3px) scale(1.03);\n      box-shadow: 0 16px 34px rgba(10,102,194,0.34), 0 0 0 6px rgba(10,102,194,0.10);\n      color: #ffffff;\n    }\n\n    .ols-linkedin-pill:hover::before { left: 120%; }\n\n    .ols-linkedin-icon {\n      width: 18px;\n      height: 18px;\n      display: block;\n      flex-shrink: 0;\n    }\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\n    .ols-note-title {\n      display: flex;\n      align-items: center;\n      gap: 14px;\n      margin-bottom: 20px;\n    }\n\n    .ols-note-icon {\n      width: 52px;\n      height: 52px;\n      border-radius: 16px;\n      background: var(--navy);\n      color: #ffffff;\n      display: grid;\n      place-items: center;\n      font-size: 24px;\n      font-weight: 800;\n      flex-shrink: 0;\n    }\n\n    .ols-note-title h2,\n    .ols-related-card h2 {\n      margin: 0;\n      font-size: clamp(28px, 3.5vw, 42px);\n      line-height: 1.15;\n      font-weight: 800;\n      color: #111827;\n      letter-spacing: -0.03em;\n    }\n\n    .ols-related-card h2 { margin-bottom: 14px; }\n\n    .ols-note-card p,\n    .ols-note-card li,\n    .ols-related-card p,\n    .ols-attribution-card p {\n      font-size: clamp(15px, 1.3vw, 18px);\n      line-height: 1.65;\n      font-weight: 300;\n      color: var(--body-text);\n    }\n\n    .ols-note-card strong,\n    .ols-related-card strong,\n    .ols-attribution-card strong {\n      font-weight: 700;\n      color: var(--navy);\n    }\n\n    .ols-key-box {\n      margin-top: 20px;\n      background: var(--soft-green);\n      border: 1px solid rgba(63, 143, 70, 0.25);\n      border-radius: 20px;\n      padding: 18px 20px;\n    }\n\n    .ols-key-box p {\n      margin: 0;\n      font-weight: 400;\n      color: var(--navy);\n    }\n\n    .ols-ms-grid {\n      display: grid;\n      grid-template-columns: repeat(2, minmax(0, 1fr));\n      gap: 18px;\n      margin-top: 26px;\n    }\n\n    .ols-ms-card {\n      position: relative;\n      display: grid;\n      grid-template-rows: auto 1fr auto;\n      min-height: 285px;\n      padding: 24px;\n      border-radius: 24px;\n      border: 1px solid rgba(28, 36, 75, 0.13);\n      background:\n        radial-gradient(circle at top right, rgba(37, 99, 235, 0.13), transparent 34%),\n        linear-gradient(135deg, #ffffff 0%, #f8fbff 100%);\n      color: var(--navy);\n      text-decoration: none;\n      overflow: hidden;\n      box-shadow: var(--inner-shadow);\n      transition: transform 0.24s ease, box-shadow 0.24s ease, border-color 0.24s ease, background 0.24s ease;\n    }\n\n    .ols-ms-card:hover {\n      transform: translateY(-6px);\n      border-color: rgba(37, 99, 235, 0.28);\n      box-shadow: 0 24px 52px rgba(28, 36, 75, 0.15);\n      color: var(--navy);\n    }\n\n    .ols-ms-card::before {\n      content: \"\";\n      position: absolute;\n      top: -60px;\n      right: -60px;\n      width: 145px;\n      height: 145px;\n      border-radius: 50%;\n      background: rgba(37, 99, 235, 0.08);\n      transition: transform 0.28s ease, background 0.28s ease;\n    }\n\n    .ols-ms-card:hover::before {\n      transform: scale(1.22);\n      background: rgba(37, 99, 235, 0.13);\n    }\n\n    .ols-ms-visual {\n      position: relative;\n      z-index: 1;\n      min-height: 94px;\n      display: flex;\n      align-items: center;\n      justify-content: center;\n      margin-bottom: 18px;\n    }\n\n    .ols-ms-icon {\n      position: relative;\n      width: 142px;\n      height: 94px;\n    }\n\n    .ols-ms-line,\n    .ols-ms-axis,\n    .ols-ms-curve,\n    .ols-ms-peak,\n    .ols-ms-tube,\n    .ols-ms-detector,\n    .ols-ms-ion,\n    .ols-ms-dot,\n    .ols-ms-arrow,\n    .ols-ms-label-mini {\n      position: absolute;\n      display: block;\n    }\n\n    .ols-ms-tube {\n      left: 6px;\n      top: 32px;\n      width: 92px;\n      height: 28px;\n      border-radius: 999px;\n      border: 3px solid rgba(28, 36, 75, 0.28);\n      background: linear-gradient(180deg, #ffffff, #edf4ff);\n    }\n\n    .ols-ms-detector {\n      right: 7px;\n      top: 25px;\n      width: 24px;\n      height: 44px;\n      border-radius: 8px;\n      background: var(--navy);\n      box-shadow: 0 8px 18px rgba(28, 36, 75, 0.22);\n    }\n\n    .ols-ms-ion {\n      width: 20px;\n      height: 20px;\n      border-radius: 50%;\n      background: var(--blue);\n      box-shadow: 0 6px 14px rgba(37, 99, 235, 0.24);\n    }\n\n    .ols-ms-ion::after {\n      content: \"+\";\n      position: absolute;\n      inset: 0;\n      display: grid;\n      place-items: center;\n      color: #ffffff;\n      font-size: 14px;\n      font-weight: 800;\n    }\n\n    .ols-ms-device .ols-ms-ion.i1 { left: 18px; top: 36px; }\n    .ols-ms-device .ols-ms-ion.i2 { left: 52px; top: 36px; transform: scale(0.82); opacity: 0.85; }\n    .ols-ms-device .ols-ms-arrow { left: 72px; top: 45px; width: 44px; height: 3px; border-radius: 999px; background: rgba(201, 151, 58, 0.86); }\n    .ols-ms-device .ols-ms-arrow::after { content: \"\"; position: absolute; right: -1px; top: 50%; transform: translateY(-50%); border-left: 10px solid rgba(201,151,58,0.86); border-top: 6px solid transparent; border-bottom: 6px solid transparent; }\n\n    .ols-ms-ram .ols-ms-axis.x { left: 13px; right: 10px; bottom: 20px; height: 3px; background: rgba(28,36,75,0.32); border-radius: 999px; }\n    .ols-ms-ram .ols-ms-axis.y { left: 18px; top: 14px; bottom: 18px; width: 3px; background: rgba(28,36,75,0.32); border-radius: 999px; }\n    .ols-ms-ram .ols-ms-peak.p1 { left: 44px; bottom: 20px; width: 7px; height: 30px; background: var(--blue); border-radius: 999px 999px 0 0; }\n    .ols-ms-ram .ols-ms-peak.p2 { left: 72px; bottom: 20px; width: 7px; height: 58px; background: var(--navy); border-radius: 999px 999px 0 0; }\n    .ols-ms-ram .ols-ms-peak.p3 { left: 102px; bottom: 20px; width: 7px; height: 42px; background: var(--gold); border-radius: 999px 999px 0 0; }\n\n    .ols-ms-diatomic .ols-ms-axis.x { left: 13px; right: 10px; bottom: 20px; height: 3px; background: rgba(28,36,75,0.32); border-radius: 999px; }\n    .ols-ms-diatomic .ols-ms-axis.y { left: 18px; top: 14px; bottom: 18px; width: 3px; background: rgba(28,36,75,0.32); border-radius: 999px; }\n    .ols-ms-diatomic .ols-ms-peak.p1 { left: 47px; bottom: 20px; width: 8px; height: 55px; background: var(--blue); border-radius: 999px 999px 0 0; }\n    .ols-ms-diatomic .ols-ms-peak.p2 { left: 72px; bottom: 20px; width: 8px; height: 36px; background: var(--navy); border-radius: 999px 999px 0 0; }\n    .ols-ms-diatomic .ols-ms-peak.p3 { left: 97px; bottom: 20px; width: 8px; height: 14px; background: var(--gold); border-radius: 999px 999px 0 0; }\n    .ols-ms-diatomic .ols-ms-label-mini { left: 43px; top: 7px; color: var(--blue); font-size: 12px; font-weight: 800; }\n\n    .ols-ms-fragment .ols-ms-axis.x { left: 13px; right: 10px; bottom: 20px; height: 3px; background: rgba(28,36,75,0.32); border-radius: 999px; }\n    .ols-ms-fragment .ols-ms-axis.y { left: 18px; top: 14px; bottom: 18px; width: 3px; background: rgba(28,36,75,0.32); border-radius: 999px; }\n    .ols-ms-fragment .ols-ms-peak.p1 { left: 38px; bottom: 20px; width: 7px; height: 25px; background: var(--blue); border-radius: 999px 999px 0 0; }\n    .ols-ms-fragment .ols-ms-peak.p2 { left: 63px; bottom: 20px; width: 7px; height: 62px; background: var(--navy); border-radius: 999px 999px 0 0; }\n    .ols-ms-fragment .ols-ms-peak.p3 { left: 91px; bottom: 20px; width: 7px; height: 35px; background: var(--gold); border-radius: 999px 999px 0 0; }\n    .ols-ms-fragment .ols-ms-peak.p4 { left: 118px; bottom: 20px; width: 7px; height: 46px; background: #c81e1e; border-radius: 999px 999px 0 0; }\n    .ols-ms-fragment .ols-ms-label-mini { right: 8px; top: 6px; color: #c81e1e; font-size: 12px; font-weight: 800; }\n\n    .ols-ms-card h3 {\n      position: relative;\n      z-index: 1;\n      margin: 0 0 10px;\n      font-size: 23px;\n      line-height: 1.2;\n      font-weight: 800;\n      letter-spacing: -0.02em;\n      color: #111827;\n    }\n\n    .ols-ms-card p {\n      position: relative;\n      z-index: 1;\n      margin: 0;\n      font-size: 15px;\n      line-height: 1.6;\n      font-weight: 300;\n      color: var(--body-text);\n    }\n\n    .ols-ms-card,\n    .ols-ms-card *,\n    .ols-ms-card:hover,\n    .ols-ms-card:hover *,\n    .ols-related-item,\n    .ols-related-item *,\n    .ols-related-item:hover,\n    .ols-related-item:hover * {\n      text-decoration: none !important;\n    }\n\n    .ols-ms-meta {\n      position: relative;\n      z-index: 1;\n      display: inline-flex;\n      align-items: center;\n      justify-content: center;\n      margin-top: 20px;\n      padding: 10px 14px;\n      border-radius: 999px;\n      background: var(--navy);\n      color: #ffffff;\n      font-size: 13px;\n      font-weight: 700;\n      width: fit-content;\n      transition: background 0.22s ease, transform 0.22s ease;\n    }\n\n    .ols-ms-card:hover .ols-ms-meta {\n      background: var(--blue);\n      transform: translateX(4px);\n    }\n\n    .ols-related-grid {\n      display: grid;\n      grid-template-columns: repeat(3, minmax(0, 1fr));\n      gap: 16px;\n      margin-top: 18px;\n    }\n\n    .ols-related-item {\n      border: 1px solid var(--border);\n      border-radius: 18px;\n      padding: 18px;\n      background: #ffffff;\n      color: var(--navy);\n      text-decoration: none;\n      font-weight: 600;\n      line-height: 1.5;\n      transition: transform 0.2s ease, box-shadow 0.2s ease, color 0.2s ease;\n    }\n\n    .ols-related-item:hover {\n      transform: translateY(-2px);\n      box-shadow: 0 10px 22px rgba(28, 36, 75, 0.08);\n      color: var(--blue);\n    }\n\n    .ols-attribution-card {\n      background: linear-gradient(135deg, #ffffff 0%, #f8fbff 100%);\n    }\n\n    .ols-attribution-card p {\n      margin: 0;\n      font-size: 14px;\n      color: var(--grey-text);\n    }\n\n    @media (max-width: 1050px) {\n      .ols-revision-layout { grid-template-columns: 1fr; }\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-revision-layout { padding: 14px 12px 44px; }\n      .ols-title-card, .ols-note-card, .ols-related-card, .ols-attribution-card { padding: 24px 18px; border-radius: 22px; }\n      .ols-note-title { align-items: flex-start; }\n      .ols-ms-grid, .ols-related-grid { grid-template-columns: 1fr; }\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      .ols-ms-card { min-height: 255px; }\n    }\n  <\/style>\n\n  <div class=\"ols-revision-layout\">\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 Atomic Structure and The Periodic Table<\/h4>\r\n\r\n    <ul class=\"ols-topic-list\">\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/atomic-structure\/\">Atomic Structure<\/a>\r\n      <\/li>\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/mass-spectrometry\/\">Mass Spectrometry<\/a>\r\n\r\n        <ul class=\"ols-subtopic-list\">\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/mass-spectrometry\/the-mass-spectrometer\/\">The Mass Spectrometer<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/mass-spectrometry\/ram-calculations\/\">RAM Calculations<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/mass-spectrometry\/predicting-diatomic-mass-spectra\/\">Predicting Diatomic Mass Spectra<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/mass-spectrometry\/identifying-compounds-from-mass-spectra\/\">Identifying Compounds from Mass Spectra<\/a>\r\n          <\/li>\r\n        <\/ul>\r\n      <\/li>\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/quantum-model\/\">Quantum Model<\/a>\r\n      <\/li>\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/ionisation-energy\/\">Ionisation Energy<\/a>\r\n\r\n        <ul class=\"ols-subtopic-list\">\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/ionisation-energy\/introduction-to-ionisation-energy\/\">Introduction to Ionisation Energy<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/ionisation-energy\/successive-ionisation-energy\/\">Successive Ionisation Energy<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/ionisation-energy\/trends-in-a-period\/\">Trends in a Period<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/ionisation-energy\/trends-in-a-group\/\">Trends in a Group<\/a>\r\n          <\/li>\r\n        <\/ul>\r\n      <\/li>\r\n    <\/ul>\r\n  <\/div>\r\n\r\n  <div class=\"ols-topic-group\">\r\n    <h4>Next Topics<\/h4>\r\n\r\n    <ul class=\"ols-topic-list\">\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-3-bonding-structure\/\">Bonding &amp; Structure<\/a>\r\n      <\/li>\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/\">Organic Chemistry &amp; Alkanes<\/a>\r\n      <\/li>\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-5-alkenes\/\">Alkenes<\/a>\r\n      <\/li>\r\n    <\/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\r\n        if (!href || href === '#' || href.charAt(0) === '#') {\r\n          return;\r\n        }\r\n\r\n        var linkPath = normalisePath(new URL(href, window.location.origin).pathname);\r\n\r\n        if (!linkPath) {\r\n          return;\r\n        }\r\n\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\r\n        var parentLi = parentSub.closest('li');\r\n\r\n        if (parentLi) {\r\n          parentLi.classList.add('parent-active', 'active-main');\r\n\r\n          var parentLink = parentLi.querySelector(':scope > a');\r\n\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>\r\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-international\/\">Edexcel International<\/a> \/\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/\">Topic 2 Atomic Structure &amp; The Periodic Table<\/a> \/\n        <span>Mass Spectrometry<\/span>\n      <\/nav>\n\n      <header class=\"ols-title-card\">\n        <h1>Mass Spectrometry<\/h1>\n        <p class=\"ols-page-intro\">Use this landing page to move quickly between the key mass spectrometry revision pages for Topic 2. Each card links to a focused page covering the instrument, RAM calculations, isotopic peak patterns and molecular ion or fragmentation evidence.<\/p>\n\n        <div class=\"ols-badges\">\n          <div class=\"ols-badge\">Exam board: Edexcel International<\/div>\n          <div class=\"ols-badge\">Topic 2: Atomic Structure &amp; The Periodic Table<\/div>\n          <div class=\"ols-badge\">Level: A Level Chemistry<\/div>\n        <\/div>\n\n        <div class=\"ols-author\">\n          <img decoding=\"async\" class=\"ols-author-avatar-img\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/Author-Profile.jpeg\" alt=\"Dr. Mohammed Al-Fatah\">\n\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>Choose a Mass Spectrometry Page<\/h2>\n        <\/div>\n\n        <p>Mass spectrometry separates positive ions according to their <strong>mass-to-charge ratio<\/strong>, written as <strong>m\/z<\/strong>. These pages build from the operation of the mass spectrometer through to isotope abundance, relative atomic mass and interpreting molecular spectra.<\/p>\n\n        <div class=\"ols-key-box\">\n          <p><strong>Key idea:<\/strong> A mass spectrum is evidence. The positions of the peaks show m\/z values, while the peak heights show relative abundance.<\/p>\n        <\/div>\n\n        <div class=\"ols-ms-grid\">\n          <a class=\"ols-ms-card\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/mass-spectrometry\/the-mass-spectrometer\/\">\n            <div class=\"ols-ms-visual\">\n              <div class=\"ols-ms-icon ols-ms-device\" aria-hidden=\"true\">\n                <span class=\"ols-ms-tube\"><\/span>\n                <span class=\"ols-ms-detector\"><\/span>\n                <span class=\"ols-ms-ion i1\"><\/span>\n                <span class=\"ols-ms-ion i2\"><\/span>\n                <span class=\"ols-ms-arrow\"><\/span>\n              <\/div>\n            <\/div>\n            <h3>The Mass Spectrometer<\/h3>\n            <p>Revise vaporisation, ionisation, acceleration, deflection, detection and why ions are separated by m\/z.<\/p>\n            <span class=\"ols-ms-meta\">Open revision page<\/span>\n          <\/a>\n\n          <a class=\"ols-ms-card\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/mass-spectrometry\/ram-calculations\/\">\n            <div class=\"ols-ms-visual\">\n              <div class=\"ols-ms-icon ols-ms-ram\" aria-hidden=\"true\">\n                <span class=\"ols-ms-axis x\"><\/span>\n                <span class=\"ols-ms-axis y\"><\/span>\n                <span class=\"ols-ms-peak p1\"><\/span>\n                <span class=\"ols-ms-peak p2\"><\/span>\n                <span class=\"ols-ms-peak p3\"><\/span>\n              <\/div>\n            <\/div>\n            <h3>RAM Calculations<\/h3>\n            <p>Use isotopic mass and percentage abundance data to calculate relative atomic mass using weighted means.<\/p>\n            <span class=\"ols-ms-meta\">Open revision page<\/span>\n          <\/a>\n\n          <a class=\"ols-ms-card\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/mass-spectrometry\/predicting-diatomic-mass-spectra\/\">\n            <div class=\"ols-ms-visual\">\n              <div class=\"ols-ms-icon ols-ms-diatomic\" aria-hidden=\"true\">\n                <span class=\"ols-ms-label-mini\">3 peaks<\/span>\n                <span class=\"ols-ms-axis x\"><\/span>\n                <span class=\"ols-ms-axis y\"><\/span>\n                <span class=\"ols-ms-peak p1\"><\/span>\n                <span class=\"ols-ms-peak p2\"><\/span>\n                <span class=\"ols-ms-peak p3\"><\/span>\n              <\/div>\n            <\/div>\n            <h3>Predicting Diatomic Mass Spectra<\/h3>\n            <p>Predict molecular ion peak patterns for diatomic molecules using isotope combinations and probability ratios.<\/p>\n            <span class=\"ols-ms-meta\">Open revision page<\/span>\n          <\/a>\n\n          <a class=\"ols-ms-card\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/mass-spectrometry\/identifying-compounds-from-mass-spectra\/\">\n            <div class=\"ols-ms-visual\">\n              <div class=\"ols-ms-icon ols-ms-fragment\" aria-hidden=\"true\">\n                <span class=\"ols-ms-label-mini\">M\u207a<\/span>\n                <span class=\"ols-ms-axis x\"><\/span>\n                <span class=\"ols-ms-axis y\"><\/span>\n                <span class=\"ols-ms-peak p1\"><\/span>\n                <span class=\"ols-ms-peak p2\"><\/span>\n                <span class=\"ols-ms-peak p3\"><\/span>\n                <span class=\"ols-ms-peak p4\"><\/span>\n              <\/div>\n            <\/div>\n            <h3>Identifying Compounds from Mass Spectra<\/h3>\n            <p>Use molecular ion peaks and fragment peaks to support compound identification from a mass spectrum.<\/p>\n            <span class=\"ols-ms-meta\">Open revision page<\/span>\n          <\/a>\n        <\/div>\n      <\/article>\n\n      <article class=\"ols-note-card purple\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">\u2713<\/div>\n          <h2>How to Use These Pages<\/h2>\n        <\/div>\n\n        <p>Start with the instrument so that you understand how ions are made and detected. Then move to RAM calculations, because isotope abundance links directly to peak heights. Finally, use the diatomic and compound identification pages to practise interpreting spectra as chemical evidence.<\/p>\n\n        <div class=\"ols-key-box\">\n          <p><strong>Exam focus:<\/strong> When explaining a spectrum, distinguish clearly between peak position and peak height. Peak position is linked to m\/z. Peak height or relative intensity is linked to relative abundance.<\/p>\n        <\/div>\n      <\/article>\n\n      <section class=\"ols-related-card\">\n        <h2>Related Topic 2 Pages<\/h2>\n        <p>Use these pages to connect mass spectrometry with atomic structure, isotopes and ionisation energy.<\/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-international\/topic-2-atomic-structure-and-the-periodic-table\/atomic-structure\/\">Atomic Structure<\/a>\n          <a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/quantum-model\/\">Quantum Model<\/a>\n          <a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/ionisation-energy\/\">Ionisation Energy<\/a>\n          <a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/ionisation-energy\/introduction-to-ionisation-energy\/\">Introduction to Ionisation Energy<\/a>\n          <a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/ionisation-energy\/successive-ionisation-energy\/\">Successive Ionisation Energy<\/a>\n          <a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/\">Next Topic: Bonding &amp; Structure<\/a>\n        <\/div>\n      <\/section>\n\n      <section class=\"ols-attribution-card\">\n        <p><strong>Copyright notice:<\/strong> This revision page, including its written explanations, layout and teaching sequence, is produced for Online Learning System by Dr. Mohammed Al-Fatah. It is intended for student revision and may not be copied, redistributed or republished without permission.<\/p>\n      <\/section>\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-international\/topic-2-atomic-structure-and-the-periodic-table\/mass-spectrometry\/#webpage\",\n            \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/mass-spectrometry\/\",\n            \"name\": \"Mass Spectrometry Revision Notes\",\n            \"description\": \"A Level Chemistry landing page for mass spectrometry, including the mass spectrometer, RAM calculations, predicting diatomic mass spectra and identifying compounds from mass spectra.\",\n            \"inLanguage\": \"en-GB\",\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\": \"Mass spectrometry\"\n              },\n              {\n                \"@type\": \"Thing\",\n                \"name\": \"Relative atomic mass\"\n              },\n              {\n                \"@type\": \"Thing\",\n                \"name\": \"Mass-to-charge ratio\"\n              }\n            ],\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            }\n          },\n          {\n            \"@type\": \"BreadcrumbList\",\n            \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/mass-spectrometry\/#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 International\",\n                \"item\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/\"\n              },\n              {\n                \"@type\": \"ListItem\",\n                \"position\": 4,\n                \"name\": \"Topic 2 Atomic Structure and The Periodic Table\",\n                \"item\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/\"\n              },\n              {\n                \"@type\": \"ListItem\",\n                \"position\": 5,\n                \"name\": \"Mass Spectrometry\",\n                \"item\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-2-atomic-structure-and-the-periodic-table\/mass-spectrometry\/\"\n              }\n            ]\n          }\n        ]\n      }\n      <\/script>\n    <\/main>\n  <\/div>\n<\/section>\n\n","protected":false},"excerpt":{"rendered":"<p>Revision Notes \/ A Level Chemistry \/ Edexcel International \/ Topic 2 Atomic Structure &amp; The Periodic Table \/ Mass Spectrometry Mass Spectrometry Use this landing page to move quickly between the key mass spectrometry revision pages for Topic 2. Each card links to a focused page covering the instrument, RAM calculations, isotopic peak patterns [&hellip;]<\/p>\n","protected":false},"author":12,"featured_media":0,"parent":3985,"menu_order":1,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-3987","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/3987","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=3987"}],"version-history":[{"count":0,"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/3987\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/3985"}],"wp:attachment":[{"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/media?parent=3987"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}