Question

O2 exist but S2 do not exist why​

Answer 1

Oxygen is diatomic,  so it exists as O2, whereas S2 is not. It exists as S8.

Answer 2

Answer:

Probably because Sulfur forms single bonds rather than double bonds as an element. It exists as disulfide but as an ion with two negative charges, not as an element. Oxygen does not have strong Vander Wall forces among atoms and so it exists as a gas at room temperature.

hope this will help u