The correct order of the second ionisation potential of carbon, nitrogen, oxygen and fluorine is

Options

A. `C gt N gt O gt F`
B. `O gt N gt F gt C`
C. `O gt F gt N gt C`
D. `F gt O gt N gt C`

Answer

C

Explanation

The ionization potential increases across the period but the second ionization potential of oxygen is highest among them because after the removal of `1e^(-)`, the `2e^(-)` is to be removed from half filled orbital which is difficult.