$A$ metalloid is

Which of the following orders regarding thermal stability of hydrides $MH_3$ of group $15$ is correct?

Assertion : Molecular nitrogen is less reactive than molecular oxygen.
Reason : The bond length of $N_2$ is shorter than that of oxygen.

In the following reaction,identify the nature of the product formed by the complete hydrolysis of the underlined atom at $R.T.$:
$\underline{N}F_3 + H_2O \longrightarrow \text{No reaction}$

How does concentrated $HNO_3$ react with aluminium?

Among the following compounds,which on heating do not produce $N_2$?