Of the following,the non-existent compound is

The correct order of boiling points of hydrides of $15^{th}$ group elements is

State the electronic configuration of group-$15$ elements.

$p$-Block elements form acidic,basic,and amphoteric oxides. Explain each property by giving two examples and also write the reactions of these oxides with water.

Nitrogen gas is obtained by thermal decomposition of .... .

$NH_3 + O_2 \xrightarrow[\Delta ]{Pt} A + H_2O;$ $A + O_2 \to B;$ $B + O_2 + H_2O \to C$
$A, B$ and $C$ are