The solution of sodium metal in liquid ammonia is strongly reducing due to the presence of which of the following in the solution?

Identify the correct statements from the following.
$A$: Alkali metals are strong reducing agents.
$B$: $KO_2$ is a diamagnetic oxide.
$C$: Hydration enthalpy of $Li^{+}$ is the highest among alkali metal ions.

Which of the following statements is correct regarding the solubility of carbonates?

Statement $I$: An alloy of lithium and magnesium is used to make aircraft plates.
Statement $II$: The magnesium ions are important for cell-membrane integrity.
In the light of the above statements,choose the correct answer from the options given below.

Consider the following statements.
$I$. $Cs^{+}$ ion is more highly hydrated than other alkali metal ions.
$II$. Among the alkali metals,only lithium forms a stable nitride by direct combination with nitrogen.
$III$. Among the alkali metals $Li, Na, K, Rb$,the metal $Rb$ has the highest melting point.
$IV$. Among the alkali metals $Li, Na, K, Rb$,only $Li$ forms peroxide when heated with oxygen.
Select the correct statement.

The given reaction is the result of which process?
$Na_2CO_3 \cdot 10H_2O \xrightarrow[open]{air} Na_2CO_3 \cdot H_2O + 9H_2O$