Nitrogen shows different oxidation states in the range of:

Consider the following statements:-
$I. \, PCl_3$ hydrolyses in the presence of moisture giving fumes of $HCl$.
$II. \, PCl_5$ exists as $[PCl_4]^+[PCl_6]^-$ in the solid state.
$III. \, $All the five bonds in the $PCl_5$ molecule are equivalent.
Choose the correct statements.

Nitrogen forms $N_2$,but phosphorus is converted from $P_2$ to $P_4$. Which of the following is the reason for this?

Which of the following oxyacids contains both $P-H$ and $P-P$ bonds simultaneously?

Given below are two statements:
Statement-$I$: Element '$X$' and '$Y$' are the most and least electronegative elements,respectively,among $N, As, Sb$ and $P$. The nature of the oxides $X_{2}O_{3}$ and $Y_{2}O_{3}$ is acidic and amphoteric,respectively.
Statement-$II$: $BCl_{3}$ is covalent in nature and gets hydrolysed in water. It produces $[B(OH)_{4}]^{-}$ and $HCl$ in aqueous medium.

Which one of the following compounds on strong heating evolves ammonia gas?