When the first ionization energies are plotted against atomic number,the peaks are occupied by:

The incorrect relation among the following is

Ionization energy increases in the order

Which of the following orders for ionisation energy is correct?

The first ionization enthalpies of $C$,$N$,and $F$ are $1086$,$1402$,and $1681 \, kJ \, mol^{-1}$ respectively. Which of the following values is the most likely first ionization enthalpy of $O$ ($1310$ or $1510 \, kJ \, mol^{-1}$)?

The first ionisation energies (in $kJ \ mol^{-1}$) of four consecutive elements of the second period are given in the options. The first ionisation energy of nitrogen is