Name two molecules each having one atom, two atoms, three atoms and four atoms.
Helium (He) and Neon (Ne) are monoatomic molecules.
Chlorine (Cl2) and Oxygen (O2) are diatomic molecules.
Water (H2O) and carbon dioxide (CO2) are triatomic molecules.
Ammonia (NH3) and hydrogen peroxide (H2O2) are tetra-atomic molecules.