Arrange the following oxides in the correct order of their acidic character:
$N_2O_3$ $(I)$,$P_2O_3$ $(II)$,$N_2O_5$ $(III)$,$As_2O_3$ $(IV)$

Phosphorus has three allotropic forms:
$(i)$ white phosphorus
$(ii)$ red phosphorus and
$(iii)$ black phosphorus.
Write the difference between white and red phosphorus on the basis of their structure and reactivity.

Given below are two statements:
Statement $I$: The $N-N$ single bond is weaker and longer than the $P-P$ single bond.
Statement $II$: Compounds of group $15$ elements in $+3$ oxidation state readily undergo disproportionation reactions.
In the light of the above statements,choose the correct answer from the options given below:

Write the structure of pyrophosphoric acid.

Sodium nitrite is reacted with $H_2SO_4$ to form $NaHSO_4$,$HNO_3$,water and $X$. Gold is dissolved in aqua regia to form water,$AuCl_4^{-}$ and $Y$. $X$ and $Y$ are respectively

Which of the following properties of white phosphorus are shared by red phosphorus?