Element having highest $I.P.$ value is

The first ionization enthalpy $(\Delta_{i} H)$ values of the third period elements,$Na, Mg$ and $Si$ are respectively $496, 737$ and $786 \, kJ \, mol^{-1}$. Predict whether the first $\Delta_{i} H$ value for $Al$ will be more close to $575$ or $760 \, kJ \, mol^{-1}$? Justify your answer.

The first ionisation potentials $(eV)$ of $Be$ and $B$ respectively are :-

Which one of the following orders is correct for the first ionisation energies of the elements?

The sum of $IE_1 + IE_2$ and $IE_3 + IE_4$ for elements $P$ and $Q$ are given below:

Element	$IE_1 + IE_2$ $(kJ/mol)$	$IE_3 + IE_4$ $(kJ/mol)$
$P$	$2.45$	$8.82$
$Q$	$2.85$	$6.11$

Then,according to the given information,the incorrect statement$(s)$ is/are:

How would you explain the fact that the first ionization enthalpy of sodium is lower than that of magnesium but its second ionization enthalpy is higher than that of magnesium?