Why does hydrogen occur in a diatomic form rather than in a monoatomic form under normal conditions?

Explanation

The electronic configuration of hydrogen `1s^(1)`. It is short of one electron to achieve the stable electronic configuration similar to that of helium. Therefore, in order to achieve the stable electronic configuration similar to that of helium, it shares its only electron with that of some other hydrogen atom and forms a diatomic molecule `H_(2) (H-H)`.