Write the names of the compounds represented by the following chemical formulae:
$(i)$ $NaBr$
$(ii)$ $Al_{2}O_{3}$
$(iii)$ $Zn(NO_{3})_{2}$
$(iv)$ $HCl$
$(v)$ $NaCl$
$(vi)$ $CaCO_{3}$

Write the names of the following compounds:
$(a)$ $NiS$
$(b)$ $Mg(NO_3)_2$
$(c)$ $Na_2SO_4$
$(d)$ $Al(NO_3)_3$
$(e)$ $K_3PO_4$
$(f)$ $Ca_3N_2$

State whether the following statement is true or false:
The chemical formulae of cupric oxide and cuprous oxide are $CuO$ and $Cu_{2}O$ respectively.

State three rules for writing the chemical formulae.

Write the chemical formulae of the compounds formed by the following ions:
$(a)$ $Mg^{2+}$ and $S^{2-}$
$(b)$ $Cu^{2+}$ and $OH^-$
$(c)$ $Al^{3+}$ and $Br^-$
Name the compounds formed in each case.

Write the molecular formulae for the following compounds:
$(a)$ Copper $(II)$ bromide
$(b)$ Aluminium $(III)$ nitrate
$(c)$ Calcium $(II)$ phosphate
$(d)$ Iron $(III)$ sulphide
$(e)$ Mercury $(II)$ chloride
$(f)$ Magnesium $(II)$ acetate