● Vertical and horizontal trends in the Periodic Table exist for atomic radius, ionic radius, ionization
energy, electron affi nity, and electronegativity.
Guidance
Only examples of general trends across periods and down groups are required. For ionization energy the
discontinuities in the increase across a period should be covered.
● Trends in metallic and non-metallic behaviour are due to the trends above.
● Oxides change from basic through amphoteric to acidic across a period.

● Prediction and explanation of the metallic and non-metallic behaviour of an element based on its position in the Periodic Table.
● Discussion of the similarities and differences in the properties of elements in the same group, with reference to alkali metals (Group 1) and halogens (Group 17).
Guidance
Group trends should include the treatment of the reactions of alkali metals with water, alkali metals with halogens and halogens with halide ions.
● Construction of equations to explain the pH changes for reactions of Na2O, MgO, P4O10, and the oxides of nitrogen and sulfur with water.