Why alkali metals show an oxidation state of $+1$.

Which of the following statements are correct for alkali metal compounds?

$\left(\mathrm{i}\right)$ ​Superoxides are paramagnetic in nature.

$\left(\mathrm{ii}\right)$ The basic nature of hydroxides increase down the group.

$\left(\mathrm{iii}\right)$ The conductivity of chlorides in their aqueous solutions decreases down the group.

$\left(\mathrm{iv}\right)$ The fundamental nature of carbonates in aqueous solutions is due to cationic hydrolysis.

$\begin{array}{c}\mathrm{X}+{\mathrm{H}}_2\mathrm{O}\to \mathrm{NaOH}\\ \end{array}$

$\mathrm{X} \underset{400°\mathrm{C}}{\overset{{\mathrm{O}}_2}{\to }} \mathrm{Y} \begin{array}{c}{\mathrm{H}}_2\mathrm{O}\\ \overrightarrow{\mathrm{at}25°\mathrm{C}}\end{array} \mathrm{ }\mathrm{NaOH}+{\mathrm{O}}_2$     'Y'  is used in oxygenation in submarine. X and Y are: