Find the formula of the halide of a metal whose successive ionization energies are $10, 16, 25, 400, 500 \ eV \ mol^{-1}$ respectively $:-$

Generally,the first ionisation energy increases along a period. But there are some exceptions. The one which is not an exception is

Which of the following statements is incorrect?

If the first ionisation enthalpy of $Li$,$Be$,and $C$ respectively are $520$,$899$,and $1086 \ kJ \ mol^{-1}$,the first ionisation enthalpy (in $kJ \ mol^{-1}$) of $B$ will be:

Which of the following pairs has a higher ionization enthalpy?
$(i)$ $Ne$ or $Ar$ $(ii)$ $Cl$ or $F$ $(iii)$ $F$ or $O$ $(iv)$ $N$ or $O$
$(v)$ $Na$ or $K$ $(vi)$ $Cl$ or $S$ $(vii)$ $Kr$ or $Xe$ $(viii)$ $P$ or $S$

The first ionization enthalpy of $Na$,$Mg$ and $Si$,respectively,are: $496, 737$ and $786 \ kJ \ mol^{-1}$. The first ionization enthalpy $(kJ \ mol^{-1})$ of $Al$ is