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

The electronic configuration of elements $A, B$ and $C$ are $[He] 2s^1, [Ne] 3s^1$ and $[Ar] 4s^1$ respectively. Which one of the following orders is correct for the first ionization potentials (in $kJ \ mol^{-1}$) of $A, B$ and $C$?

Among the second period elements,the actual ionization enthalpies are in the order $Li < B < Be < C < O < N < F < Ne$. Explain why:
$(i)$ $Be$ has higher $\Delta_{i}H$ than $B$
$(ii)$ $O$ has lower $\Delta_{i}H$ than $N$ and $F$?

The first ionization enthalpies of $Na, Mg$ and $Si$ are respectively $496, 737$ and $786 \ kJ \ mol^{-1}$. What would be the first ionization enthalpy of $Al$ in $kJ \ mol^{-1}$?

The incorrect statement is:

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