In which of the following arrangements has order is NOT according to the property indicated against it?

Options

A. `AI^(3+) lt Mg^(2+) lt Na^(+) lt F^-)`-increasing ionic size
B. `B lt C lt F lt O`-increasing first ionisation enthalpy
C. `I lt Br lt F lt CI`-increasing electron gain enthalpy (with negative sign)
D. `Li lt Na lt K lt Rb-`increasing metallic radius

Answer

B

Explanation

Nitrogen has half filled stable configuration, `ns^(2)np^(3)`. So, ionization enthalpy of nitrogen is greater than oxygen. On moving down the group, metallic radius increases due to increases in number of shells.