# Are all molecules = made up of two different atoms?

It's most often diatomic molecules of an element like ${\text{H}}_{2}$ for hydrogen, ${\text{N}}_{2}$ for nitrogen, or ${\text{O}}_{2}$ for oxygen. But sometimes a single element can form molecules with more atoms, like ${\text{O}}_{3}$ for ozone (another molecular form of oxygen) or ${\text{S}}_{8}$ for sulfur. Single atoms of noble gases like atgon ($\text{Ar}$) may also be considered as molecules.