What is the action of chlorine on excess ammonia?

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:

$N_2O_3$ is a/an.......

Which form of phosphorus is thermodynamically most stable?

$PbF_4$ and $PbCl_4$ exist,while $PbBr_4$ and $PbI_4$ do not exist. This is due to:

Name the gas that has a smell like rotten fish.