A MOLECULE contains two or more atoms.
Since a compound contains two or more different elements,
it also contains two or more different atoms, hence the simplest
form of a compound is a molecule. As an example, a molecule of
water contains two hydrogen atoms and one oxygen atom, (written
When an element consists of two identical atoms it is called
DIATOMIC molecule. The simplest form of some elements is a molecule.
For example oxygen in air consists of molecules containing two
atoms of oxygen, (written as O2).