1. 2,2,2 Sodium Chloride as a typical Ionic Solid

2. Crystals

3. Crystalline They have regular geometric shapes
Lattice structure made up of positive and negative ions
Shape depends on arrangements of these ions
Arrangement depends on relative size and relative abundance of each type of ion
Ions are tiny – positive ions are smaller than the corresponding atoms

4. Crystal Lattice
Sodium ion
Chloride ion

5. Face-centred Cube Sodium ions are smaller than Chloride ions
2 shells as opposed to 3 shells
Ratio 1 Na+ : 1 Cl-
Relative size and number of each ion determines arrangement
Face-centred cube

6. Properties of Ionic Compounds

7. Melting and Boiling Points
High Boiling and Melting Points
Each ion held in place by 5 oppositely charged ions
There fore difficult to break away

8. Conductivity
Do not conduct when solid because electrons tightly held in full outer shells
Ions are trapped by six oppositely charge ions
Conduct with electrolysis when molten (fused) or in solution
Ions are free to move in both conditions and have electrons added at cathode and pulled off at anode causing the chemical reactions

9. Solubility Many soluble in water due to polar nature of water
Insoluble in organic solvents such as benzene and cyclopropane because these are covalent and like dissolves like

10. - - - - - Brittle + + + Force
Hard as difficult to move because every ion is firmly held by 6 other ions with opposite charge
Once they move the tiniest amount – the like charges line up and repel, and crystal shears along a plane + -
Force - + - - - +

11. Ionic materials in everyday life
You need to know two uses
Salt [sodium chloride] tablets are taken especially in hot climates to replace salt lost by sweating.
Iron sulphate tablets are taken to treat anaemia which has many causes. The iron is needed to make blood as it occupies the centre of haemoglobin molecules