The ionization energy will be higher when the electron is removed from

$X_{(g)} \to X^{+}_{(g)} + e^-$,$\Delta H = +720 \ kJ \ mol^{-1}$
Calculate the amount of energy required to convert $110 \ mg$ of $X$ atom in gaseous state into $X^{+}$ ion .................... $kJ$ (Atomic weight for $X = 7 \ g \ mol^{-1}$)

Which of the following represents the correct order of ionization enthalpy?
$(i) Be^{+} > Be$ $(ii) Be > Be^{+}$ $(iii) C > Be$ $(iv) B > Be$

The first ionisation energy of $Na$,$B$,$N$ and $O$ atoms follows the order

In the second period of the modern periodic table,two elements $X$ and $Y$ have higher first ionization enthalpy values than the preceding and succeeding elements. $X$ and $Y$ are respectively

The first ionisation enthalpies for three elements are $1314$,$1680$ and $2080 \, kJ \, mol^{-1}$,respectively. The correct sequence of the elements is