The difference in physical state between dioxygen (O₂) and sulfur (S) at room temperature boils down to their intermolecular forces and molecular weight.

Here's a breakdown:

* Dioxygen (O₂)

* Small size: Oxygen atoms are relatively small.

* Weak intermolecular forces: O₂ molecules are nonpolar and only exhibit weak London dispersion forces (Van der Waals forces) between them.

* Low molecular weight: The molecular weight of O₂ is 32 g/mol.

These factors combine to mean that dioxygen molecules have low attractive forces and can easily move around, making it a gas at room temperature.

* Sulfur (S)

* Larger size: Sulfur atoms are larger than oxygen atoms.

* Stronger intermolecular forces: Elemental sulfur exists as S₈ molecules (eight sulfur atoms joined in a ring) and exhibits stronger London dispersion forces due to their larger size and greater polarizability.

* Higher molecular weight: The molecular weight of S₈ is 256 g/mol.

The combination of these factors results in stronger intermolecular forces and a more compact structure, making sulfur a solid at room temperature.

In summary:

* Dioxygen (O₂): Small size, weak forces, low molecular weight => gas at room temperature.

* Sulfur (S₈): Larger size, stronger forces, high molecular weight => solid at room temperature.