Which non-metal does not react with water but reacts with alkali?

Given below are two statements:
Statement $I$: The $N-N$ single bond is weaker and longer than the $P-P$ single bond.
Statement $II$: Compounds of group $15$ elements in $+3$ oxidation state readily undergo disproportionation reactions.
In the light of the above statements,choose the correct answer from the options given below:

$PbO_2$ is

Which nitrogen trihalide is the least basic?

Why does the reactivity of nitrogen differ from phosphorus?

It is because of the inability of $ns^{2}$ electrons of the valence shell to participate in bonding that: