Which of the following statements is correct regarding $H_3PO_3$ and $H_3PO_4$?

White phosphorus contains

Give an example to show the effect of concentration of nitric acid on the formation of oxidation products.

When $PbO_2$ reacts with concentrated $HNO_3$,the evolved gas is:

Nitrogen exists as a diatomic molecule $(N_2)$ and phosphorus as $P_4$. Why?

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.