Give reasons for the following:

i) is less reactive at room temperature.

ii) is the strongest reducing agent amongst all the hydrides of Group 16 elements.

iii) Helium is used in diving apparatus as diluent for Oxygen.

i) The two N atoms present in molecule are bonded to each other by very strong triple covalent bonds. The energy required to dissociate the bondsis very high. As a result, is less reactive at room temperature.

ii) is the strongest reducing agent amongst all the hydrides of Group 16 elements. This is due to the fact that Te is comparatively bigger in size as compared to H, therefore, the bond is not much stronger. Further, the electronegativity is much less. Thereby making it the strongest reducing agent.

iii) Air contains large amounts of Nitrogen and the solubility of gases in liquid increases with the increase in pressure. When the sea divers dive deep into the sea, large amount of nitrogen dissolves in their blood. When the divers come to the surface, as the pressure gets to normal, nitrogen separates from the blood and cause a medical condition called blends. Therefore, to minimise the solubility and mixing of nitrogen with blood, He is added to the air cylinders which acts as diluent for Oxygen in the diving apparatus.