The atomic number of nitrogen is $7$. What will be the atomic number of the third member of the nitrogen family?

Which of the following has the highest ratio of reducing hydrogen atoms to $OH$ groups?

Which gas is used in the manufacturing of nitrogenous fertilizers?

Which of the following dissolves in hot conc. $NaOH$ solution?

Which of the following statements is $NOT$ correct?

$A$ metal $(X)$ dissolves in both dilute $HCl$ and dilute $NaOH$ to liberate $H_2$ gas. Addition of $NH_4Cl$ and excess $NH_4OH$ to an $HCl$ solution of $(X)$ produces $(Y)$ as a precipitate. $(Y)$ is also produced by adding $NH_4Cl$ to the $NaOH$ solution of $(X)$. The species $(X)$ and $(Y)$,respectively,are: