Molecule monoatomice(care au un singur atom in componenta moleculei):Ar,Ne,He(gaze nobile);
Molecule diatomice (cu 2 atomi in componenta moleculei):HCl,CO,N2;
Molecule poliatomice(de la 3 atomi in componenta moleculei in sus):HClO3,SO2,H2SO4,S8,CO2,H2CO3