Among the following transition elements, pick out the element/elements with highest second ionization energy
(a) V(At. No. 23) (v) Cr(At. No. 24)
(c) Mn(At. No. =25) (d) Cu (At. No. =29)
(e) Zn(At. No.=30)

Options

A. a and c
B. b and d
C. only c
D. only d

Answer

B

Explanation

After removal of one of one electron the `Cr^(+)` and `Cu^(+)` ions are left with stable half filled and fully filled orbitals, sufficiently higher energy is needed to remove the second electron in their case
`:.` second ionisation energy will be highest for (b) and (d)