Which of the following order is correct for the property mentioned in brackets?

Options

A. `S^(2-) gt Cl^(-) gt K^(+) gt Ca^(2+)` (Ionization energy)
B. `C lt N lt F lt O` (2nd ionisation energy)
C. `B gt Al gt Ga gt In gt Tl` (Electronegativity)
D. `Na^(+) gt Li^(+) gt Mg^(2+) gt Be^(2+) gt Al^(3+) ` (Ionic radius)

Answer

B

Explanation

Correct order `to C lt N lt F lt O (2^(nd)I.E.)`
Second electron removal from oxygen requires more energy as it acquires stable `2s^(2)2p^(3)`
configuration after removal of one electron.