The valencies (or charges) of some of the ions are given below:

Ion Valency Ion Valency

(Charge) (Charge)

Sodium ion 1+ Bromide ion 1-

Ammonium 1+ Hydroxide 1-

ion ion

Calcium ion 2+ Sulphate 2-

ion

Lead ion 2+ Phosphate 3-

Ion

Using this information, write down the formulate of the following compounds:

(i) Sodium phosphate

(ii) Ammonium sulphate

(iii) Calcium hydroxide

(iv) Lead bromide