Complete the following equations in words and then write the balanced molecular equation in each case.

(a) Zinc nitrate + sodium carbonate ⟶ …………… + ……………

(b) Iron (II) sulphate (ferrous sulphate) + sodium hydroxide ⟶ …………… + ……………

Give one reason why magnetizing a piece of steel is a physical change.

The formula of the nitride of a metal X is XN, state the formula of :

(i) it's sulphate (ii) it's hydroxide.

What is the valency of nitrogen in :

(i) NO

(ii) N₂O

(iii) NO₂