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1.3.1

Example

For each of the following compounds, determine whether it is ionic or covalent. For ionic compounds, deduce the total number of ions that can be derived from one formula unit of the compound.

Example(1) Sulphur dioxide

Sulphur dioxide consists of a non-metal, sulphur, and another non-metal, oxygen. Hence it is a
covalent compound.

Example(2) Magnesium hydroxide

Magnesium hydroxide consists of a simple cation, magnesium ion and a polyatomic anion,
hydroxide ion. Hence it is an ionic compound. Its formula is Mg(OH)₂. It consists of 1 Mg²⁺
ion and 2 OH ^– ions or a total of 3 ions.