C2 - Properties of Ionic Compounds

What type of structure do ionic compounds form?

Giant ionic lattices.

What is a giant ionic lattice?

A 3D structure where every positive ion is surrounded by negative ions, and every negative ion is surrounded by positive ions.

What forces hold ions together in a giant ionic lattice?

Strong electrostatic forces of attraction between oppositely charged ions.

What are electrostatic forces of attraction between ions also called?

Ionic bonds.

In which directions do ionic bonds act?

In all directions.

Why do ionic compounds have high melting and boiling points?

Because strong electrostatic forces of attraction require a large amount of heat energy to break.

What happens when an ionic compound is heated?

The ions vibrate more until they have enough energy to overcome the electrostatic forces and the solid melts.

What is the approximate melting point of sodium chloride?

Around 800 °C.

Why can't ionic compounds conduct electricity when solid?

The ions are locked in place and cannot move.

Why can ionic compounds conduct electricity when molten or dissolved in water?

The ions are free to move and can carry electrical charge.

When ionic compounds conduct electricity, what particles move?

The ions move, not the electrons.

Why do ionic compounds often form crystals?

Because of their regular giant ionic lattice structure.