JEE Main · 2022 · 25 Jun 2022 · Shift 2 · d and f Block Elements

The metal ion (in gaseous state) with lowest spin-only magnetic moment value is

Answer: (B)

Solution

Electronic configurations:

V^{2 +}

has

3 d^{3}

(3 unpaired electrons),

Ni^{2 +}

has

3 d^{8}

(2 unpaired electrons),

Cr^{2 +}

has

3 d^{4}

(4 unpaired electrons),

Fe^{2 +}

has

3 d^{6}

(4 unpaired electrons). The spin-only magnetic moment is

μ = n (n + 2)

BM, where

n

is the number of unpaired electrons.

Ni^{2 +}

with 2 unpaired electrons has the lowest magnetic moment.

JEE Main · 2022 · 25 Jun 2022 · Shift 2 · Single correct option