$(i)$ Name the body which approves the nomenclature of elements and compounds.
$(ii)$ The symbol of sodium is written as $Na$ and not as $S$. Give reason.
$(iii)$ Name one element which forms diatomic and one which forms tetraatomic molecules.

(N/A) $(i)$ The body that approves the nomenclature of elements and compounds is the International Union of Pure and Applied Chemistry $(IUPAC)$.
$(ii)$ The symbol of sodium is $Na$ because it is derived from its Latin name,$Natrium$. The symbol $S$ is reserved for sulfur.
$(iii)$ $(a)$ An element that forms a diatomic molecule is Hydrogen $(H_2)$.
$(b)$ An element that forms a tetraatomic molecule is Phosphorus $(P_4)$.