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

For second ionisation potential, electron has to be removed from valence shell of the following ions:

Ionisation energy increases from left to right in a period. However, removal of electron from half-filled or fully filled subshell requires more energy. The order for 2nd IE is : O > F > N