Which of the following compounds liberates oxygen on heating?

An ionic hydride of an alkali metal has significant covalent character and is almost unreactive towards oxygen and chlorine. This is used in the synthesis of other useful hydrides. Write the formula of this hydride. Write its reaction with $Al_2Cl_6$.

Which of the following $s$-block elements forms a nitride directly by reacting with $N_2$?

$KO_2$ is used in space and submarines because it

When heated in air,the alkali metals form various oxides. Mention the oxides formed by $Li$,$Na$ and $K$.

$A$ $s$-block element $(M)$ reacts with oxygen to form an oxide of the formula $MO_{2}$. The oxide is pale yellow in colour and paramagnetic. The element $(M)$ is: