In which of the following acids,$P-P$ bond is present?

The pentavalence in phosphorus is more stable as compared to that of nitrogen even though they belong to the same group. It is due to

When $NH_3$ reacts with $Cl_2$,which of the following statements are correct?
$(a)$ $NCl_3$ is formed when $Cl_2$ is in excess.
$(b)$ $N_2$ is formed when $Cl_2$ is in excess.
$(c)$ $N_2$ is formed when $NH_3$ is in excess.
$(d)$ $NCl_3$ is formed when $NH_3$ is in excess.

How many $P-O-P$ linkages are there in $P_4O_{10}$?

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:

Which of the following oxy acids of phosphorus is a reducing agent and monobasic?