The electronic configuration of an element with the largest difference between the $1^{st}$ and $2^{nd}$ ionisation energies is

Match the following List-$I$ and List-$II$ and select the correct answer using the codes given below.
List-$I$ (Successive Ionization Enthalpy) $\left( kJ \, mol^{-1} \right)$ List-$II$

Element	$IE_1$	$IE_2$	$IE_3$	Code	Element
$1$	$2080$	$3963$	$6130$	$(a)$	$H$
$2$	$520$	$7297$	$11810$	$(b)$	$Li$
$3$	$900$	$1758$	$14810$	$(c)$	$Be$
$4$	$800$	$2428$	$3660$	$(d)$	$B$
-	-	-	-	$(e)$	$Ne$

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A:$ The energy required to form $Mg^{2+}$ from $Mg$ is much higher than that required to produce $Mg^{+}$.
Reason $R:$ $Mg^{2+}$ is a small ion and carries more charge than $Mg^{+}$.
In the light of the above statements,choose the correct answer from the options given below:

The first ionization potential values (in $eV$) for nitrogen and oxygen atoms are respectively:

Discuss and compare the trend in ionisation enthalpy of the elements of group-$1$ with those of group-$17$ elements.

Given below are two statements: One is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: The first ionization enthalpy of $O$ is lower than that of $N$ and $F$.
Reason $R$: The loss of an electron from $O$ leads to a stable half-filled $p$ orbital.
In light of the above statements, choose the most appropriate answer from the options given below: