Given reasons for the following: Dioxygen is a gas but sulphur is a solid.

Oxygen is smaller in size as compared to sulphur due to which, it can effectively form π−π bonds and form O₂ molecule. Also, the intermolecular forces in oxygen are weak van der Waal's forces, which cause it to exist as a gas. On the other hand, sulphur does not form S₂ molecule but exists as a puckered structure held together by strong covalent bonds. Hence, it is solid.