Question

Why oxygen is gas while others are solid p block elements?

Answer 1

Oxygen is smaller in size and thus due to its small size complete its octet by forming pstraight pi = pstraight pi bond. Therefore, O2 is a discrte molecule and the intermolecular forces of attraction are weak vander waals forces. Hence, O2 is a gas. While sulphur is large in size, cannot form pstraight pi = pstraight pi bonds. Therefore, in order to gain stability, it exists as S8 which is a solid.