The vapour at 200^oC consists mostly of S₈ rings

At 600^oC the gas mainly consists of S₂ molecules

The oxidation state of sulphur is never less than +4 in its compounds

S₂ molecule is paramagnetic.

Nitrogen cannot form $$d\pi - p\pi$$ bond.

Single N – N bond is weaker than the single P – P bond

N₂O₄ has two resonance structures

The stability of hydrides increases from NH₃ to BiH₃ in group 15 of the periodic table

$$BH_4^-$$

$$BF_6^{3-}$$

$$B(OH)_4^-$$

$$BO_2^-$$

All the members exhibit +3 oxidation state

Because of similar properties the separation of lanthanoids is not easy.

Availability of 4f electrons results in the formation of compounds in +4 state for all the members of the series.

There is a gradual decrease in the radii of the members with increasing atomic number in the series.