Chemistry·Cambridge A-Level

Atomic Structure

Syllabus Learning Objectives

01understand 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

02identify and describe protons, neutrons and electrons in terms of their relative charges and relative masses

03understand the terms atomic and proton number; mass and nucleon number

04describe the distribution of mass and charge within an atom

05define the term isotope in terms of numbers of protons and neutrons

06understand the notation x y A for isotopes, where x is the mass or nucleon number and y is the atomic or proton number

07understand the terms: • shells, sub-shells and orbitals • principal quantum number (n) • ground state, limited to electronic configuration

08describe 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

09describe the order of increasing energy of the sub-shells within the first three shells and the 4s and 4p sub-shells

10describe the electronic configurations to include the number of electrons in each shell, sub-shell and orbital

11understand and use the electrons in boxes notation e.g. for Fe: [Ar]

12describe and sketch the shapes of s and p orbitals

13describe a free radical as a species with one or more unpaired electrons

14define and use the term first ionisation energy, IE

15understand that ionisation energies are due to the attraction between the nucleus and the outer electron

16describe the behaviour of beams of protons, neutrons and electrons moving at the same velocity in an electric field

17determine the numbers of protons, neutrons and electrons present in both atoms and ions given atomic or proton number, mass or nucleon number and charge

18state and explain qualitatively the variations in atomic radius and ionic radius across a period and down a group

19state that and explain why isotopes of the same element have the same chemical properties

20state that and explain why isotopes of the same element have different physical properties, limited to mass and density

21explain the electronic configurations in terms of energy of the electrons and inter-electron repulsion

22determine 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: 1s22s22p63s23p63d64s2 (full electronic configuration) or [Ar] 3d64s2 (shorthand electronic configuration)

23construct equations to represent first, second and subsequent ionisation energies

24identify and explain the trends in ionisation energies across a period and down a group of the Periodic Table

25identify and explain the variation in successive ionisation energies of an element

26explain 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

27deduce the electronic configurations of elements using successive ionisation energy data

28deduce the position of an element in the Periodic Table using successive ionisation energy data