Which of the following choices represent the correct order of first ionisation enthalpy ?

Options

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

Answer

C

Explanation

Ionization energy is the minimum amount of energy required to remove the outermost electron from an isolated gaseous atom. Quantitatively, it depends on the attraction between electron present on outermost shell and nucleus. Greater the interaction between outermost electron and nucleus, higher will be its ionization enthalpy. So correct order of first it must be
`B lt C lt N lt O lt F`
But due to extra stable half-filled electronic configuration of p orbital of N has more value of first ionization enthalpy than oxygen hence, correct order is
`B lt Clt N gt O gt F`