Give reasons for the following:
(i) Oxygen is a gas but sulpher is a solid.
(ii) `O_(3)` acts as a powerful oxidising agent.
(iii) `BiH_(3)` is the strongest reducing agent amongst all the hydrides of Groups 15 elements.

Explanation

(i) 0xgyen is a gas but sulphur is a solid, because oxygen exists as a diatomic molecule while sulphur exists as a polyatomic :r,nolecule hence sulphur mass will be more, therefore it will have more vandet-Waal forces, hence more boiling point.
(ii) O zone act as p.owerful oxidising agent becuase it liberates atom of nascent oxygen `O_(2)rarrO_(2)+O` Monatonic oxygen is more powerful oxidizer than either `O_(2) or O_(3).`
(iii) `BiH_(3)` is strongest reducing agentdue to its lowest dissociation energy due to its longer bond length.