The weakest base among $KOH$,$NaOH$,$Ca(OH)_2$,and $Zn(OH)_2$ is:

The blue colour of the solution (metal dissolved in liquid ammonia) is due to

Which alkali metal emits blue colour light in a flame test?

$NaOH$ (solid) $+ CO \xrightarrow{200^\circ C} X$; product $X$ is

Identify the correct statements from the following:
$A$) Among alkali metal ions,$Li^+$ has the highest hydration enthalpy.
$B$) The boiling point of alkali metals increases from $Li$ to $Cs$.
$C$) The density of $K$ is less than that of $Na$ and $Rb$.
$D$) $Li$ has a strong tendency to form superoxide.

$NaOH$ is prepared by the method: