Match the entries of column I with appropriate entries of column II and choose the correct option out of the four options given.

A-r, B-s, C-p, D-q

The correct answer is option 1. A-r, B-s, C-p, D-q

(A) Cu²⁺: [Ar]3d⁹

No of unpaired electrons = 1

Magnetic moment = \(\sqrt{1(1+2)}\) = \(\sqrt{3}\) ≈ 1.8 BM

(B) Fe²⁺: [Ar]3d⁶

No of unpaired electrons = 4

Magnetic moment = \(\sqrt{4(4+2)}\) = \(\sqrt{24}\) ≈ 5.0 BM

(C) Ni²⁺: [Ar]3d⁸

No of unpaired electrons = 2

Magnetic moment = \(\sqrt{2(2+2)}\) = \(\sqrt{8}\) ≈ 2.9 BM

(D) Co²⁺: [Ar]3d⁷

No of unpaired electrons = 3

Magnetic moment = \(\sqrt{3(3+2)}\) = \(\sqrt{15}\) ≈ 4.0 BM