Identify the element which has the highest second ionisation enthalpy.

Observe the following statements.
Statement $(A)$: In general,the ionisation potential value decreases on moving down in the group.
Statement $(B)$: The $1$st ionisation potential of sodium is greater than that of potassium.
Correct answer is:

The first ionization potentials $\left( eV \right)$ of $Be$ and $B$ respectively are:

Which among the following elements has the lowest value of $IE_1$?

Which particle may be removed from a stable neutral atom with the least energy change?

Calculate the energy required to convert all atoms in $4.8 \ g$ of $Mg$ to $Mg^{2+}$ in the vapour state. $IE_1$ and $IE_2$ of $Mg$ are $740 \ kJ / mol$ and $1450 \ kJ / mol$ respectively.