atomic number, mass number, isotope, Avogadro constant (N_A), relative isotopic mass, relative atomic mass (A_r), relative formula mass and relative molecular mass (M_r)

(i) the concept of amount of substance (moles) and its use to perform calculations involving: masses of substances, empirical and molecular formulae, percentage composition, percentage yields, water of crystallisation

(ii) the techniques and procedures used in experiments to measure masses of solids

Both the classical (carbon-12 based) and revised (Avogadro constant based) definitions of the mole are accepted.

(i) the use of the concept of amount of substance (moles) to perform calculations involving: concentration (including titration calculations and calculations for making and diluting standard solutions)

(ii) the techniques and procedures used in experiments to measure volumes of solutions; the techniques and procedures used in experiments to prepare a standard solution from a solid or more concentrated solution and in acid-base titrations

balanced full and ionic chemical equations, including state symbols

conventions for representing the distribution of electrons in atomic orbitals; the shapes of s- and p-orbitals

The 'electrons in boxes' model.

the electronic configuration, using sub-shells and atomic orbitals, of:

(i) atoms from hydrogen to krypton
(ii) ions of the s- and p-block of Periods 1 to 4
(iii) the outer sub-shell structures of s- and p-block elements of other periods

No explanation required.

how knowledge of the structure of the atom developed in terms of a succession of gradually more sophisticated models; interpretation of these and other examples of such developing models

To include:
- evidence for small dense nucleus (Geiger–Marsden experiment)
- the make-up of atoms and ions in terms of protons, neutrons and electrons
- evidence for electrons shells [from ionisation energies, EL(q), and spectra, EL(w)].

fusion reactions: lighter nuclei join to give heavier nuclei (under conditions of high temperature and pressure); this is how certain elements are formed

Nuclear equations are required.

chemical bonding in terms of electrostatic forces; simple electron ‘dot-and-cross’ diagrams to describe the electron arrangements in ions and covalent and dative covalent bonds

In covalent bonds there is a balance between the repulsive forces between the nuclei and the attractive forces between the nuclei and the electrons.

the bonding in giant lattice (metallic, ionic, covalent network) and simple molecular structure types; the typical physical properties (melting point, solubility in water, electrical conductivity) characteristic of these structure types

Explanations of physical properties limited to:
- electrostatic attractions between molecules are weaker than electrostatic attractions in giant structures
- charged particles able to move (electrons in metals; ions in molten or aqueous ionic substances).

use of the electron pair repulsion principle, based on ‘dot-and-cross’ diagrams, to predict, explain and name the shapes of simple molecules (such as BeCl₂, BF₃, CH₄, NH₃, H₂O and SF₆) and ions (such as NH₄⁺) with up to six outer pairs of electrons (any combination of bonding pairs and lone pairs); assigning bond angles to these structures

No treatment of hybridisation or molecular orbitals is expected but ideas of bond angles being altered by the lone pairs present should be included, for example the bond angles of: CH₄ (109.5°), NH₃ (107°), H₂O (104.5°).

structures of compounds that have a sodium chloride type lattice

Ionic bonding is the overall attraction in a lattice and is made up of attraction between ions of different charge and repulsion between ions of the same charge.

the periodic table as a list of elements in order of atomic (proton) number that groups elements together according to their common properties;
using given information, make predictions concerning the properties of an element in a group; the classification of elements into s-, p- and d-blocks

periodic trends in the melting points of elements in Periods 2 and 3, in terms of structure and bonding

the relationship between the position of an element in the s- or p-block of the periodic table and the charge on its ion;
the names and formulae of NO₃^-, SO₄^2-, CO₃^2-, OH^-, NH₄⁺, HCO₃^-, Cu²⁺, Zn²⁺, Pb²⁺, Fe²⁺, Fe³⁺;
formulae and names for compounds formed between these ions and other given anions and cations

When used without oxidation states, ‘nitrate’ can be assumed to be NO₃^- and ‘sulfate’ can be assumed to be SO₄^2-.

a description and comparison of the following properties of the elements and compounds of Mg, Ca, Sr and Ba in Group 2: reactions of the elements with water and oxygen, thermal stability of the carbonates, solubilities of hydroxides and carbonates

the term ionisation enthalpy;
equations for the first ionisation of elements;
explanation of trends in first ionisation enthalpies for Periods 2 and 3 and groups and the resulting differences in reactivities of s- and p-block metals in terms of their ability to lose electrons

Across a period, outermost electrons in the same shell are being more strongly attracted by more protons (explanation of the small drops mid-period not required).
Down a group, electrons are in shells that are further from the nucleus and thus attracted less.

charge density of an ion and its relation to the thermal stability of the Group 2 carbonates

Smaller ions with the same charge have higher charge density and thus distort the large carbonate ion, so that the compound decomposes at lower temperature.

the solubility of compounds formed between the following cations and anions: Li⁺, Na⁺, K⁺, Ca²⁺, Ba²⁺, Cu²⁺, Fe²⁺, Fe³⁺, Ag⁺, Pb²⁺, Zn²⁺, Al³⁺, NH⁴⁺, CO₃^2-, SO₄^2-, Cl^-, Br^-, I^-, OH^- , NO₃^-;
colours of any precipitates formed;
use of these ions as tests e.g. Ba²⁺ as a test for SO₄^2-;
a sequence of tests leading to the identification of a salt containing the ions above

Knowledge of the reaction of 3+ cations with CO₃^2- is not required

the terms: acid, base, alkali, neutralisation;
techniques and procedures for making soluble salts by reacting acids and bases and insoluble salts by precipitation reactions

Knowledge of the names and formulae of the mineral acids, HCl, HNO₃ and H₂SO₄ will be expected.

the basic nature of the oxides and hydroxides of Group 2 (Mg-Ba)

Description only, including equations, for reactions of Group 2 oxides and hydroxides with water and acids.

the electromagnetic spectrum in order of increasing frequency and energy and decreasing wavelength: infrared, visible, ultraviolet

transitions between electronic energy levels in atoms:

(i) the occurrence of absorption and emission atomic spectra in terms of transition of electrons between electronic energy levels
(ii) the features of these spectra, similarities and differences
(iii) the relationship between the energy emitted or absorbed and the frequency of the line produced in the spectra, \(∆E = hν\)
(iv) the relationship between frequency, wavelength and the speed of electromagnetic radiation, \(c = νλ\)
(v) flame colours of Li⁺, Na⁺, K⁺, Ca²⁺, Ba²⁺, Cu²⁺

Similarities: both are line spectra; lines in same position for a given element; lines become closer at higher frequencies; series of lines representing transitions to or from a particular energy level.
Differences: bright/coloured lines on a black background or black lines on coloured/bright background.

use of data from a mass spectrum to determine relative abundance of isotopes and calculate the relative atomic mass of an element