# Can a molecule only contain one kind of atom?

$N O , N {O}_{2} , C {O}_{2} , C {H}_{4} , C O$ are ALL GASEOUS molecules at normal temperatures and pressure.............
On the other hand, I could point to ${N}_{2}$, or ${O}_{2}$, or ${O}_{3}$, or ${F}_{2}$. These species are also molecular, and as elemental species they contain only the one element.