Which of the following acids exists in a polymeric form?

Which of the following oxides is paramagnetic?

The electronegativity of a group $13$ element '$E$' is the same as that of $Ge$ (on the Pauling scale and up to one decimal point). The $CORRECT$ statements about $E^{3+}$ are:
$A$. It can act as a reducing agent.
$B$. It can act as an oxidizing agent.
$C$. $E^{3+}$ is more stable than $E^+$.
$D$. The standard electrode potential value for $E^{3+}/E$ is positive.

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

What is the $P-P-P$ bond angle in white phosphorus?

The oxide of nitrogen formed by thermal decomposition of $NH_4NO_3$ is