$HNO_3$ is produced in good yield by which of the following methods?

Which of the following is used to obtain $Ag$ from $AgNO_3$?

Find the correct statements related to group $15$ hydrides.
$A$. Reducing nature increases from $NH_3$ to $BiH_3$
$B$. Tendency to donate lone pair of electrons decreases from $NH_3$ to $BiH_3$
$C$. The stability of hydrides decreases from $NH_3$ to $BiH_3$
$D$. $HEH$ bond angle decreases from $NH_3$ to $SbH_3$ ($E$ = Elements of group $15$)
Choose the correct answer from the options given below:

Pure $N_2$ gas is obtained from

Write four characteristic properties of $p$-block elements.

What is the maximum concentration of aqueous $HNO_3$ that can be obtained by distillation with concentrated $H_2SO_4$ in terms of percentage by mass (in $\%$)?