1.1. Extended tier only

There are three types of giant structure – ionic, metallic and macromolecular.

Sodium nitride is an ionic compound. Draw a diagram that shows the formula of the compound, the charges on the ions and the arrangement of the valency electrons around the negative ion.

Use x to represent an electron from a sodium atom. Use o to represent an electron from a nitrogen atom.

1.2. Extended tier only

i) Describe metallic bonding.

[3]

ii) Use the above ideas to explain why:

metals are good conductors of electricity,
metals are malleable.

[3]