The $1^{st}$ ionization enthalpy for $Mg$ is $+737 \text{ kJ/mol}$. The most probable estimated value of the $2^{nd}$ ionization enthalpy of $Mg$ is . . . . . . .

If first ionization enthalpies of element $X$ and $Y$ are $419 \ kJ \ mol^{-1}$ and $590 \ kJ \ mol^{-1}$,respectively and second ionization enthalpies of $X$ and $Y$ are $3069 \ kJ \ mol^{-1}$ and $1145 \ kJ \ mol^{-1}$,respectively. Then the correct statement is :-

The second ionization potential of $Li$,$Be$,and $B$ is in the order:

If first ionization enthalpy $(\Delta_i H)$ values of $Na$,$Mg$ and $Si$ are respectively $496$,$737$ and $786 \ kJ \ mol^{-1}$,the first ionization enthalpy value of $Al$ (in $kJ \ mol^{-1}$) will be

The electronic configuration which is associated with the highest first ionisation enthalpy is:

The ionisation energy of nitrogen is more than that of oxygen because :-