Ionic compounds are made up of positive metal ions and negative non-metal ions arranged in a crystal lattice. In ionic compounds like sodium chloride, the oppositely charged ions are held together by strong electrostatic forces of attraction. Potassium oxide and lithium oxide are examples where the metal ions (potassium and lithium) outnumber the oxygen ions in a ratio of about 1:2, as represented by their chemical formulas K2O and Li2O.

1. Giant Ionic Structure Ionic compounds are made up of positive ions of a metal and negative ions of a non-metal. They are arranged in a crystal lattice such as the picture shown on the left. (Sodium Chloride)

2. Giant Ionic Structure From this picture,we can see that the oppositely charged Sodium and Chloride ions are held by strong electrostatic forces of attraction.

3. Example 1: Potassium Oxide From this diagram,we can see that the ion in grey is Potassium and the ion in red is Oxygen. The chemical formula is K 2 O because the no. Of Oxygen ions are almost twice the number of Potassium ions. (->+)

4. Example 2: Lithium Oxide From the diagram,we can see that the ions in red are Oxygen and the ions in Purple are Lithium. The Chemical Formula is Li 2 O,because the number of Oxygen ions is almost twice the number of Lithium ions,as in the previous slide.

5. Done by: Muhd Haris (33) 3H SOURCES : Google Image Search My Chemistry Notes Wikipedia