Nitrogen can be obtained from air by removing

Which of the following hydrides of nitrogen is most acidic in nature?

In the nitrogen group,as we move from $N$ to $Sb$,the $H-M-H$ bond angle in the hydrides approaches $90^o$ because ......

Red phosphorus can be obtained from white phosphorus by:

Sodium hydroxide solution reacts with phosphorus to give phosphine. To bring about this reaction,we need

The following are some statements related to $VA$ group hydrides:
$I$. Reducing property increases from $NH_3$ to $BiH_3$.
$II$. Tendency to donate lone pair decreases from $NH_3$ to $BiH_3$.
$III$. Thermal stability of hydrides decreases from $NH_3$ to $BiH_3$.
$IV$. Bond angle of hydrides decreases from $NH_3$ to $BiH_3$.
The correct statements are: