the correct order of econd ionisation potential of C,N,O and F isi need explanation

The second ionization energy refers to the energy required to remove the electron from the corresponding mono-valent cation of the respective atom. The atoms: C, N, O and F belong to 2nd period of the periodic table.

Just like second ionization energy like the first IE is affected by size, effective nuclear charge, type of orbital from which the electron is being removed and electronic configuration.

It is expected to increase from left to right in the periodic table with decrease in the atomic size. However oxygen has greater second ionization energy than fluorine and also nitrogen.

Reason: Since Oxygen atom gets stable electronic configuration, 2s²2p³after removing one electron, the O⁺shows greater ionization energy than F⁺as well as N⁺.

Thank You
Ruchi
Askiitians Faculty