Why is dioxygen a gas but sulphur a solid?

(a) Complete the followingh chemical reaction equations : (i) Cu+HNO_(3 (dilute))to (ii) P_4+NaOH+H_2Oto (b) (i) why does R_3P=O exist but R_3N=O does not ? (R=alkyl group) (ii) why is dioxygen a gas but sulphur a solid ? (iii) why are halogens coloured ?

(a) What happens when : (i) HCl reacts with finely powdered iron. (ii) Cl_(2) reacts with hot concentrated solution of NaOH. (b) Give appropriate reason for each of the following : (i) Sulphur vapour exhibits some paramagnetic character. (ii) NH_(3) more basic than PH_(3) . (iii) Dioxygen is a gas but sulphur a solid.

Give reasons : (a) H_(3)PO_(3) undergoes disproportination reaction but H_(3)PO_(4) does not (b) Dioxygen is a gas while sulphur is a solid (c ) When Cl_(2) reacts with excess of F_(2) compound formed is CiF_(3) " and not " FCl_(3) .

Oxygen is gas but sulphur is solid because

Write a balanced chemical equation of the following reactions and also classify them. Hydrogen sulphide gas reacts with oxygen gas to form solid sulphur and liquid water.