Form giant ionic structures - see previous page
High melting points - Large amount of energy needed to overcome strong attractive force between oppositely charged ions
Do not conduct electricity in their solid forms - Ions are held in fixed positions in lattice so movement of charge is not possible
Conduct electricity when they are molten or dissolved in water - Lattice breaks down and ions can move freely
Brittle - If a stress is applied to the crystal, the ion layers move slightly, bringing like charges in contact with each other. These repel each other, causing the crystal to fracture.

Ionic Bonding and Compounds