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

Which of the following elements has the highest metallic character?
Element $-$ $IP$ (Ionization Potential)

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:

The second ionization potential of elements is invariably higher than the first ionization potential because:

The given electronic configurations are for elements $X$,$Y$,and $Z$. Note that these configurations represent ions of the elements:
$X = [Ne] \, 3s^2 \, 3p^5$
$Y = [Ne] \, 3s^2 \, 3p^6$
$Z = [Ne] \, 3s^2 \, 3p^4$
Determine the correct statement regarding the energy changes associated with these configurations.

The $3^{rd}$ ionisation energy amongst $Li$,$Be$,$B$ and $C$ is lowest for