Topic 2a - Ionic Compounds

Structure of ionic compounds

Properties of ionic compounds

Structure called a giant ionic lattice

Closely packed regular arrangement

Very strong electrostatic forces

Dot and cross diagrams

3D models

Ball and stick models

Advantages

Disadvantages

Show how ionic compounds were formed

Don't show structure of the compound

Don't show relative sizes of ions

Advantages

Disadvantages

Show relative sizes of ions

Regular pattern in an ionic crystal

Only let you see outer layer of compound

Advantages

Disadvantages

Show regular pattern

How the ions are arranged

Sometimes ions aren't shown to scale

Suggest there are gaps between ions and there aren't

High melting and boiling points due to strong electrostatic attraction

Most ionic compounds dissolve easily in water

Don't conduct electricity when solid because ions held in fixed positions but when melted or dissolved they can