State why- Lithium on being heated in the air mainly forms the monoxide and not the peroxide and sodium is stored in kerosene oil.

The mobilities of alkali metal ions in aqueous solution are: ${\text{Li}}^{+}<{\text{Na}}^{+}<{\text{K}}^{+}<{\text{Rb}}^{+}<{\text{Cs}}^{+}$.
 

Comment on the following- Lithium is the only alkali metal to form a nitride directly.

Comment on the following:

$\mathrm{LiF}$ is more soluble than $\mathrm{KF}$ in ethanol.

Comment on the following.

$\mathrm{LiI}$ is more soluble than $\mathrm{KI}$ in Ethanol. 

Account for the following:

The hydroxides of alkali metals are strong bases.