Why is dioxygen gas but sulphur a solid?

Explanation

Due to the small size and high electronegative oxygen atom form `p pi - p pi` double bond O = O. The intermolecular forces in oxygen are weak vander wall forces in oxygen are weak vander wall forces and therefore oxygen exist as a gas.
On the other hand sulphur doesn.t form stable `p pi - p pi` bond and doesn.t exist as `S_2`. It is linked by single bond and four polyatomic complex molecules having eight atoms per molecule (`S_2`) and have puckered ring structure. Therefore, S atom are strongly held together and it exist as a solid.