{"id":7919,"date":"2026-09-14T21:37:41","date_gmt":"2026-09-14T20:37:41","guid":{"rendered":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/"},"modified":"2026-09-14T22:02:37","modified_gmt":"2026-09-14T21:02:37","slug":"topic-1-atomic-structure","status":"publish","type":"page","link":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/","title":{"rendered":"Topic 1 Atomic Structure"},"content":{"rendered":"\n<div class=\"ols-cie1-page\">\n\n  <aside class=\"ols-sidebar\">\n  <div class=\"ols-sidebar-header\">\n    <h3>Revision Notes<\/h3>\n    <p>Cambridge International AS Level Chemistry<\/p>\n  <\/div>\n  <div class=\"ols-topic-group\">\n    <h4>Topic 1 Atomic Structure<\/h4>\n    <ul class=\"ols-topic-list\">\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/\">Topic overview<\/a><\/li>\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/atomic-structure\/\">1.1 \/ 1.2 Atomic Structure and Isotopes<\/a><\/li>\n<li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/charged-particles-in-electric-fields\/\">1.1 Charged Particles in Electric Fields<\/a><\/li>\n<li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/atomic-and-ionic-radii\/\">1.1 Atomic and Ionic Radii<\/a><\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/mass-spectrometry\/\">1.2 Mass Spectrometry<\/a>\n        <ul class=\"ols-subtopic-list\">\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/mass-spectrometry\/the-mass-spectrometer\/\">The Mass Spectrometer<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/mass-spectrometry\/ram-calculations\/\">RAM Calculations<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/mass-spectrometry\/predicting-diatomic-mass-spectra\/\">Predicting Diatomic Mass Spectra<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/mass-spectrometry\/identifying-compounds-from-mass-spectra\/\">Identifying Compounds from Mass Spectra<\/a><\/li>\n        <\/ul>\n      <\/li>\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/electron-configuration\/\">1.3 Electron Configuration<\/a><\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/ionisation-energy\/\">1.4 Ionisation Energy<\/a>\n        <ul class=\"ols-subtopic-list\">\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/ionisation-energy\/introduction-to-ionisation-energy\/\">Introduction to Ionisation Energy<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/ionisation-energy\/successive-ionisation-energies\/\">Successive Ionisation Energies<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/ionisation-energy\/trends-in-a-period\/\">Trends in a Period<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/ionisation-energy\/trends-in-a-group\/\">Trends in a Group<\/a><\/li>\n        <\/ul>\n      <\/li>\n    <\/ul>\n  <\/div>\n  <div class=\"ols-topic-group\">\n    <h4>Other Topics<\/h4>\n    <ul class=\"ols-topic-list\">\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-3-chemical-bonding\/\">Topic 3 Chemical Bonding<\/a><\/li>\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-4-states-of-matter\/\">Topic 4 States of Matter<\/a><\/li>\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-9-the-periodic-table-chemical-periodicity\/\">Topic 9 Chemical Periodicity<\/a><\/li>\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-13-an-introduction-to-as-level-organic-chemistry\/\">Topic 13 Introduction to Organic Chemistry<\/a><\/li>\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-14-hydrocarbons\/\">Topic 14 Hydrocarbons<\/a><\/li>\n    <\/ul>\n  <\/div>\n<\/aside>\n<script>\r\n(function() {\r\n  function normalisePath(path) {\r\n    return String(path || '')\r\n      .split('?')[0]\r\n      .split('#')[0]\r\n      .replace(\/\\\/+$\/, '')\r\n      .toLowerCase();\r\n  }\r\n\r\n  function highlightActive() {\r\n    var sidebar = document.querySelector('.ols-sidebar');\r\n    if (!sidebar) return false;\r\n\r\n    var currentPath = 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linear-gradient(135deg, #064e3b 0%, #059669 55%, #6ee7b7 100%); }\n    .ols-cie1-visual--waste { background: linear-gradient(135deg, #334155 0%, #64748b 55%, #cbd5e1 100%); }\n    .ols-cie1-visual--alkane { background: linear-gradient(135deg, #1f2937 0%, #4b5563 55%, #9ca3af 100%); }\n    .ols-cie1-visual--naming { background: linear-gradient(135deg, #0f766e 0%, #14b8a6 55%, #99f6e4 100%); }\n    .ols-cie1-card--soon { opacity: 0.62; cursor: default; }\n    .ols-cie1-card-status--soon { background: #e5e7eb; color: #374151; }\n<\/style>\n\n  <!-- BREADCRUMB BAR -->\n  <div class=\"ols-cie1-breadcrumb-bar\">\n    <div class=\"ols-cie1-container\">\n      <nav class=\"ols-cie1-breadcrumb\" 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\/cie\/\">Cambridge International (CIE)<\/a> \/\n          <span>Topic 1 Atomic Structure<\/span>\n        <\/nav>\n    <\/div>\n  <\/div>\n\n  <!-- INTRO -->\n  <section class=\"ols-cie1-intro\">\n    <div class=\"ols-cie1-container\">\n      <div class=\"ols-cie1-intro-inner\">\n        <div>\n          <div class=\"ols-cie1-eyebrow\">Cambridge International AS Level Chemistry<\/div>\n          <h1>Topic 1<br>Atomic Structure<\/h1>\n          <div class=\"ols-cie1-accent-bar\"><\/div>\n          <p class=\"ols-cie1-intro-lead\">Topic 1 covers the particles in the atom, isotopes, the arrangement of electrons in shells, sub-shells and orbitals, and ionisation energy as evidence for electronic structure. These pages cover all four parts, with the mass spectrometry pages included because they build on isotopes (the spectra themselves are examined in Topic 22).<\/p>\n        <\/div>\n        <div class=\"ols-cie1-info-grid\">\n          <div class=\"ols-cie1-info-card\"><div class=\"ols-cie1-info-card-label\">Exam Papers<\/div><div class=\"ols-cie1-info-card-value\">Papers 1 &amp; 2<\/div><div class=\"ols-cie1-info-card-sub\">9701\/1 and 9701\/2 (AS Level)<\/div><\/div>\n          <div class=\"ols-cie1-info-card\"><div class=\"ols-cie1-info-card-label\">Learning Outcomes<\/div><div class=\"ols-cie1-info-card-value\">1.1.1 &#8211; 1.4.8<\/div><div class=\"ols-cie1-info-card-sub\">4 parts<\/div><\/div>\n          <div class=\"ols-cie1-info-card\"><div class=\"ols-cie1-info-card-label\">Topic Parts<\/div><div class=\"ols-cie1-info-card-value\">4 of 4 live<\/div><div class=\"ols-cie1-info-card-sub\">1.1, 1.2, 1.3, 1.4<\/div><\/div>\n          <div class=\"ols-cie1-info-card\"><div class=\"ols-cie1-info-card-label\">Exam Board<\/div><div class=\"ols-cie1-info-card-value\">Cambridge<\/div><div class=\"ols-cie1-info-card-sub\">CIE 9701 (2025-2027)<\/div><\/div>\n        <\/div>\n      <\/div>\n    <\/div>\n  <\/section>\n\n  <!-- TOPIC CARDS -->\n  <section class=\"ols-cie1-topics\">\n    <div class=\"ols-cie1-container\">\n      <div class=\"ols-cie1-section-header\">\n        <h2 class=\"ols-cie1-section-title\">Revision Notes<\/h2>\n        <p class=\"ols-cie1-section-sub\">Work through each part of Cambridge Topic 1 in a structured sequence.<\/p>\n      <\/div>\n      <div class=\"ols-cie1-cards-grid\">\n        <!-- Card 1: 1.1 \/ 1.2 Atomic Structure and Isotopes -->\n        <a class=\"ols-cie1-card ols-cie1-card--available\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/atomic-structure\/\">\n          <div class=\"ols-cie1-card-img-wrap\">\n            <div class=\"ols-cie1-visual ols-cie1-visual--ionic\">\n              <div class=\"ols-cie1-visual-panel\">\n                <div class=\"ols-cie1-visual-kicker\">Particles<\/div>\n                <div class=\"ols-cie1-visual-main\">Atomic<br>Structure<\/div>\n                <div class=\"ols-cie1-config-line\" aria-hidden=\"true\"><span>p\u207a n\u2070 e\u207b<\/span><\/div>\n              <\/div>\n            <\/div>\n            <div class=\"ols-cie1-card-num\">1<\/div>\n          <\/div>\n          <div class=\"ols-cie1-card-body\">\n            <p class=\"ols-cie1-card-title\">1.1 \/ 1.2 Atomic Structure and Isotopes<\/p>\n            <p class=\"ols-cie1-card-desc\">Protons, neutrons and electrons, atomic and nucleon number, particle numbers in atoms and ions, and isotopes (1.1.1 to 1.1.6, 1.2.1 to 1.2.4).<\/p>\n            <span class=\"ols-cie1-card-cta\">Start revising<svg viewBox=\"0 0 16 16\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M3 8h10M9 4l4 4-4 4\"><\/path><\/svg><\/span>\n          <\/div>\n        <\/a>\n\n        <a class=\"ols-cie1-card ols-cie1-card--available\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/charged-particles-in-electric-fields\/\">\n          <div class=\"ols-cie1-card-img-wrap\">\n            <div class=\"ols-cie1-visual ols-cie1-visual--ionic\">\n              <div class=\"ols-cie1-visual-panel\">\n                <div class=\"ols-cie1-visual-kicker\">Deflection<\/div>\n                <div class=\"ols-cie1-visual-main\">Charged<br>Particles<\/div>\n                <div class=\"ols-cie1-config-line\" aria-hidden=\"true\"><span>e\u207b \u2191 p\u207a \u2193 n\u2070 \u2192<\/span><\/div>\n              <\/div>\n            <\/div>\n            <div class=\"ols-cie1-card-num\">2<\/div>\n          <\/div>\n          <div class=\"ols-cie1-card-body\">\n            <p class=\"ols-cie1-card-title\">1.1 Charged Particles in Electric Fields<\/p>\n            <p class=\"ols-cie1-card-desc\">How beams of protons, neutrons and electrons behave in an electric field, and what the deflections show about charge and mass (1.1.5).<\/p>\n            <span class=\"ols-cie1-card-cta\">Start revising<svg viewBox=\"0 0 16 16\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M3 8h10M9 4l4 4-4 4\"><\/path><\/svg><\/span>\n          <\/div>\n        <\/a>\n\n        <a class=\"ols-cie1-card ols-cie1-card--available\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/atomic-and-ionic-radii\/\">\n          <div class=\"ols-cie1-card-img-wrap\">\n            <div class=\"ols-cie1-visual ols-cie1-visual--ionic\">\n              <div class=\"ols-cie1-visual-panel\">\n                <div class=\"ols-cie1-visual-kicker\">Trends<\/div>\n                <div class=\"ols-cie1-visual-main\">Atomic and<br>Ionic Radii<\/div>\n                <div class=\"ols-cie1-config-line\" aria-hidden=\"true\"><span>Na\u207a &lt; Na &lt; Cl\u207b<\/span><\/div>\n              <\/div>\n            <\/div>\n            <div class=\"ols-cie1-card-num\">3<\/div>\n          <\/div>\n          <div class=\"ols-cie1-card-body\">\n            <p class=\"ols-cie1-card-title\">1.1 Atomic and Ionic Radii<\/p>\n            <p class=\"ols-cie1-card-desc\">Atomic radius across a period and down a group, cations and anions compared with their atoms, and the isoelectronic ions of Period 3 (1.1.7, 9.1.1).<\/p>\n            <span class=\"ols-cie1-card-cta\">Start revising<svg viewBox=\"0 0 16 16\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M3 8h10M9 4l4 4-4 4\"><\/path><\/svg><\/span>\n          <\/div>\n        <\/a>\n\n        <!-- Card 2: 1.2 Mass Spectrometry -->\n        <a class=\"ols-cie1-card ols-cie1-card--available\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/mass-spectrometry\/\">\n          <div class=\"ols-cie1-card-img-wrap\">\n            <div class=\"ols-cie1-visual ols-cie1-visual--forces\">\n              <div class=\"ols-cie1-visual-panel\">\n                <div class=\"ols-cie1-visual-kicker\">Instrument<\/div>\n                <div class=\"ols-cie1-visual-main\">Mass<br>Spectrometry<\/div>\n                <div class=\"ols-cie1-config-line\" aria-hidden=\"true\"><span>m\/z<\/span><\/div>\n              <\/div>\n            <\/div>\n            <div class=\"ols-cie1-card-num\">4<\/div>\n          <\/div>\n          <div class=\"ols-cie1-card-body\">\n            <p class=\"ols-cie1-card-title\">1.2 Mass Spectrometry<\/p>\n            <p class=\"ols-cie1-card-desc\">How a mass spectrometer separates isotopes, relative isotopic and atomic mass, RAM from abundances and diatomic spectra (with 2.1.2; spectra examined in Topic 22).<\/p>\n            <span class=\"ols-cie1-card-cta\">Start revising<svg viewBox=\"0 0 16 16\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M3 8h10M9 4l4 4-4 4\"><\/path><\/svg><\/span>\n          <\/div>\n        <\/a>\n\n        <!-- Card 3: 1.3 Electrons in Atoms -->\n        <a class=\"ols-cie1-card ols-cie1-card--available\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/electron-configuration\/\">\n          <div class=\"ols-cie1-card-img-wrap\">\n            <div class=\"ols-cie1-visual ols-cie1-visual--shapes\">\n              <div class=\"ols-cie1-visual-panel\">\n                <div class=\"ols-cie1-visual-kicker\">Orbitals<\/div>\n                <div class=\"ols-cie1-visual-main\">Electron<br>Configuration<\/div>\n                <div class=\"ols-cie1-config-line\" aria-hidden=\"true\"><span>1s\u00b2 2s\u00b2 2p\u2076<\/span><\/div>\n              <\/div>\n            <\/div>\n            <div class=\"ols-cie1-card-num\">5<\/div>\n          <\/div>\n          <div class=\"ols-cie1-card-body\">\n            <p class=\"ols-cie1-card-title\">1.3 Electrons in Atoms<\/p>\n            <p class=\"ols-cie1-card-desc\">Shells, sub-shells and orbitals, s and p orbital shapes, filling order and the configurations of atoms and ions using s p d notation and electrons in boxes (1.3.1 to 1.3.9).<\/p>\n            <span class=\"ols-cie1-card-cta\">Start revising<svg viewBox=\"0 0 16 16\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M3 8h10M9 4l4 4-4 4\"><\/path><\/svg><\/span>\n          <\/div>\n        <\/a>\n\n        <!-- Card 4: 1.4 Ionisation Energy -->\n        <a class=\"ols-cie1-card ols-cie1-card--available\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/ionisation-energy\/\">\n          <div class=\"ols-cie1-card-img-wrap\">\n            <div class=\"ols-cie1-visual ols-cie1-visual--polarity\">\n              <div class=\"ols-cie1-visual-panel\">\n                <div class=\"ols-cie1-visual-kicker\">Energy<\/div>\n                <div class=\"ols-cie1-visual-main\">Ionisation<br>Energy<\/div>\n                <div class=\"ols-cie1-config-line\" aria-hidden=\"true\"><span>X(g) \u2192 X\u207a(g) + e\u207b<\/span><\/div>\n              <\/div>\n            <\/div>\n            <div class=\"ols-cie1-card-num\">6<\/div>\n          <\/div>\n          <div class=\"ols-cie1-card-body\">\n            <p class=\"ols-cie1-card-title\">1.4 Ionisation Energy<\/p>\n            <p class=\"ols-cie1-card-desc\">First and successive ionisation energies, the factors that decide them, and the trends across a period and down a group as evidence for electronic structure (1.4.1 to 1.4.8).<\/p>\n            <span class=\"ols-cie1-card-cta\">Start revising<svg viewBox=\"0 0 16 16\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M3 8h10M9 4l4 4-4 4\"><\/path><\/svg><\/span>\n          <\/div>\n        <\/a>\n\n      \n\n      <\/div>\n    <\/div>\n  <\/section>\n\n  <!-- SPECIFICATION -->\n  <section class=\"ols-cie1-spec-section\">\n    <div class=\"ols-cie1-container\">\n      <div class=\"ols-cie1-spec-wrap\">\n        <div class=\"ols-cie1-spec-pill\">Specification Coverage<\/div>\n        <h2 class=\"ols-cie1-spec-heading\">Topic 1 Atomic Structure &#8211; Cambridge International AS Level Chemistry<\/h2>\n        <p class=\"ols-cie1-spec-intro-text\">The following Cambridge learning outcomes state what candidates should be able to do for Topic 1. Wording is taken from the Cambridge International AS &amp; A Level Chemistry 9701 syllabus (2025-2027).<\/p>\n\n        <h3 class=\"ols-cie1-spec-group-title\">1.1 Particles in the atom and atomic radius<\/h3>\n<div class=\"ols-cie1-spec-rows\">\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--light\"><div class=\"ols-cie1-spec-code\">1.1.1<\/div><div class=\"ols-cie1-spec-text\">understand that atoms are mostly empty space surrounding a very small, dense nucleus that contains protons and neutrons; electrons are found in shells in the empty space around the nucleus<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--mid\"><div class=\"ols-cie1-spec-code ols-cie1-spec-code--mid\">1.1.2<\/div><div class=\"ols-cie1-spec-text\">identify and describe protons, neutrons and electrons in terms of their relative charges and relative masses<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--light\"><div class=\"ols-cie1-spec-code\">1.1.3<\/div><div class=\"ols-cie1-spec-text\">understand the terms atomic and proton number; mass and nucleon number<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--mid\"><div class=\"ols-cie1-spec-code ols-cie1-spec-code--mid\">1.1.4<\/div><div class=\"ols-cie1-spec-text\">describe the distribution of mass and charge within an atom<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--light\"><div class=\"ols-cie1-spec-code\">1.1.5<\/div><div class=\"ols-cie1-spec-text\">describe the behaviour of beams of protons, neutrons and electrons moving at the same velocity in an electric field<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--mid\"><div class=\"ols-cie1-spec-code ols-cie1-spec-code--mid\">1.1.6<\/div><div class=\"ols-cie1-spec-text\">determine the numbers of protons, neutrons and electrons present in both atoms and ions given atomic or proton number, mass or nucleon number and charge<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--light\"><div class=\"ols-cie1-spec-code\">1.1.7<\/div><div class=\"ols-cie1-spec-text\">state and explain qualitatively the variations in atomic radius and ionic radius across a period and down a group<\/div><\/div>\n<\/div>\n<h3 class=\"ols-cie1-spec-group-title\">1.2 Isotopes<\/h3>\n<div class=\"ols-cie1-spec-rows\">\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--mid\"><div class=\"ols-cie1-spec-code ols-cie1-spec-code--mid\">1.2.1<\/div><div class=\"ols-cie1-spec-text\">define the term isotope in terms of numbers of protons and neutrons<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--light\"><div class=\"ols-cie1-spec-code\">1.2.2<\/div><div class=\"ols-cie1-spec-text\">understand the notation (A over Z)X for isotopes, where A is the mass or nucleon number and Z is the atomic or proton number<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--mid\"><div class=\"ols-cie1-spec-code ols-cie1-spec-code--mid\">1.2.3<\/div><div class=\"ols-cie1-spec-text\">state that and explain why isotopes of the same element have the same chemical properties<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--light\"><div class=\"ols-cie1-spec-code\">1.2.4<\/div><div class=\"ols-cie1-spec-text\">state that and explain why isotopes of the same element have different physical properties, limited to mass and density<\/div><\/div>\n<\/div>\n<h3 class=\"ols-cie1-spec-group-title\">1.3 Electrons, energy levels and atomic orbitals<\/h3>\n<div class=\"ols-cie1-spec-rows\">\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--mid\"><div class=\"ols-cie1-spec-code ols-cie1-spec-code--mid\">1.3.1<\/div><div class=\"ols-cie1-spec-text\">understand the terms: \u00e2\u0080\u00a2 shells, sub-shells and orbitals \u00e2\u0080\u00a2 principal quantum number (n) \u00e2\u0080\u00a2 ground state, limited to electronic configuration<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--light\"><div class=\"ols-cie1-spec-code\">1.3.2<\/div><div class=\"ols-cie1-spec-text\">describe the number of orbitals making up s, p and d sub-shells, and the number of electrons that can fill s, p and d sub-shells<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--mid\"><div class=\"ols-cie1-spec-code ols-cie1-spec-code--mid\">1.3.3<\/div><div class=\"ols-cie1-spec-text\">describe the order of increasing energy of the sub-shells within the first three shells and the 4s and 4p sub-shells<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--light\"><div class=\"ols-cie1-spec-code\">1.3.4<\/div><div class=\"ols-cie1-spec-text\">describe the electronic configurations to include the number of electrons in each shell, sub-shell and orbital<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--mid\"><div class=\"ols-cie1-spec-code ols-cie1-spec-code--mid\">1.3.5<\/div><div class=\"ols-cie1-spec-text\">explain the electronic configurations in terms of energy of the electrons and inter-electron repulsion<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--light\"><div class=\"ols-cie1-spec-code\">1.3.6<\/div><div class=\"ols-cie1-spec-text\">determine the electronic configuration of atoms and ions given the atomic or proton number and charge, using either of the following conventions: e.g. for Fe: 1s2 2s2 2p6 3s2 3p6 3d6 4s2 (full electronic configuration) or [Ar] 3d6 4s2 (shorthand electronic configuration)<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--mid\"><div class=\"ols-cie1-spec-code ols-cie1-spec-code--mid\">1.3.7<\/div><div class=\"ols-cie1-spec-text\">understand and use the electrons in boxes notation, e.g. for Fe: [Ar] with 3d and 4s boxes<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--light\"><div class=\"ols-cie1-spec-code\">1.3.8<\/div><div class=\"ols-cie1-spec-text\">describe and sketch the shapes of s and p orbitals<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--mid\"><div class=\"ols-cie1-spec-code ols-cie1-spec-code--mid\">1.3.9<\/div><div class=\"ols-cie1-spec-text\">describe a free radical as a species with one or more unpaired electrons<\/div><\/div>\n<\/div>\n<h3 class=\"ols-cie1-spec-group-title\">1.4 Ionisation energy<\/h3>\n<div class=\"ols-cie1-spec-rows\">\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--light\"><div class=\"ols-cie1-spec-code\">1.4.1<\/div><div class=\"ols-cie1-spec-text\">define and use the term first ionisation energy, IE<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--mid\"><div class=\"ols-cie1-spec-code ols-cie1-spec-code--mid\">1.4.2<\/div><div class=\"ols-cie1-spec-text\">construct equations to represent first, second and subsequent ionisation energies<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--light\"><div class=\"ols-cie1-spec-code\">1.4.3<\/div><div class=\"ols-cie1-spec-text\">identify and explain the trends in ionisation energies across a period and down a group of the Periodic Table<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--mid\"><div class=\"ols-cie1-spec-code ols-cie1-spec-code--mid\">1.4.4<\/div><div class=\"ols-cie1-spec-text\">identify and explain the variation in successive ionisation energies of an element<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--light\"><div class=\"ols-cie1-spec-code\">1.4.5<\/div><div class=\"ols-cie1-spec-text\">understand that ionisation energies are due to the attraction between the nucleus and the outer electron<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--mid\"><div class=\"ols-cie1-spec-code ols-cie1-spec-code--mid\">1.4.6<\/div><div class=\"ols-cie1-spec-text\">explain the factors influencing the ionisation energies of elements in terms of nuclear charge, atomic\/ionic radius, shielding by inner shells and sub-shells and spin-pair repulsion<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--light\"><div class=\"ols-cie1-spec-code\">1.4.7<\/div><div class=\"ols-cie1-spec-text\">deduce the electronic configurations of elements using successive ionisation energy data<\/div><\/div>\n<div class=\"ols-cie1-spec-row ols-cie1-spec-row--mid\"><div class=\"ols-cie1-spec-code ols-cie1-spec-code--mid\">1.4.8<\/div><div class=\"ols-cie1-spec-text\">deduce the position of an element in the Periodic Table using successive ionisation energy data<\/div><\/div>\n<\/div>\n      <\/div>\n    <\/div>\n  <\/section>\n\n<script type=\"application\/ld+json\">{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@graph\": [\n    {\n      \"@type\": \"WebPage\",\n      \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/#webpage\",\n      \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/cie\/topic-1-atomic-structure\/\",\n      \"name\": \"Topic 1 Atomic Structure - Cambridge International AS Level 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International AS Level Chemistry Topic 1Atomic Structure Topic 1 covers the particles in the atom, isotopes, the arrangement of electrons in shells, sub-shells and orbitals, and ionisation energy as evidence for electronic structure. These pages cover all four parts, [&hellip;]<\/p>\n","protected":false},"author":12,"featured_media":0,"parent":7150,"menu_order":1,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-7919","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/7919","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=7919"}],"version-history":[{"count":0,"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/7919\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/7150"}],"wp:attachment":[{"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/media?parent=7919"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}