properties of ionic compounds
Brittleness
When the lattice is hit, a layer of ions is shifted so that ions with the same charges become lined up. These like charges repel from each other and so split the ionic lattice causing it to shatter - making ionic compounds brittle.
Solubility
Most ionic compounds are soluble in water. The ions become separated and surrounded by water molecules. The ions can then move, the negative ions are attracted by the positive portion of water molecules and positive ions by the negative.
Melting & boiling points
Ionic compounds have a giant ionic lattice, so there are many strong electrostatic forces of attraction between oppositely charged ions (SEFABOCIs) . It takes a lot of energy to break these bonds, so the melting and boiling points are high. This means they are solid at room temperature.
Conduction of electricity
When ionic compounds are in a solid they cannot conduct electricity because the particles are in fixed positions and can’t move. However, in liquids and gases they cannot conduct electricity move so they can conduct electricity.