When calomel reacts with $NH_4OH$ solution,the compound formed is

$P_2O_3 + H_2O \rightarrow X$
$Red \ P_4 + \text{alkali} \rightarrow Y$
$X$ and $Y$ are oxoacids of phosphorus. The number of $P-OH$ bonds in $X$ and $Y$ respectively is:

Of the different allotropes of phosphorus,the one which is most reactive is

The correct statement$(s)$ related to oxoacids of phosphorus is(are):
$(A)$ Upon heating,$H_3PO_3$ undergoes disproportionation reaction to produce $H_3PO_4$ and $PH_3$.
$(B)$ While $H_3PO_3$ can act as a reducing agent,$H_3PO_4$ cannot.
$(C)$ $H_3PO_3$ is a monobasic acid.
$(D)$ The $H$ atom of the $P-H$ bond in $H_3PO_3$ is not ionizable in water.

Phosphorous and phosphoric acids are, respectively, . . . . . . acids.

The elements $N$,$P$,$As$,$Sb$,and $Bi$ belong to which group?