Which of the following substances are soluble in concentrated $HNO_3$?

The oxyacid of phosphorus,in which phosphorus has the lowest oxidation state,is

Pure $N_2$ gas is obtained from

What happens when white phosphorus is heated with concentrated $NaOH$ solution in an inert atmosphere of $CO_{2}$?

Identify the incorrect statements about group $15$ elements :
$A$. Dinitrogen is a diatomic gas which acts like an inert gas at room temperature.
$B$. The common oxidation states of these elements are $-3, +3$ and $+5$.
$C$. Nitrogen has unique ability to form $p\pi-p\pi$ multiple bonds.
$D$. The stability of $+5$ oxidation states increases down the group.
$E$. Nitrogen shows a maximum covalency of $6$.
Choose the correct answer from the options given below.

Pure $N_2$ gas is prepared by: