Question

The correct electronic configuration and spin-only magnetic moment $(BM)$ of $G{d}^{3+}(Z=64)$, respectively, are

• A. $[Xe]5f^7$ and $8.9$
• B. $[Xe]4f^7$ and $7.9$
• C. $[Xe]5f^7$ and $7.9$
• D. $[Xe]4f^7$ and $8.9$

Answer 1

Answer: (B)

Electronic configuration of $G{d}^{3+}$ is

${}_{64}G{d}^{3+}=[Xe]4f^7$



Gd ${}^{3+}$ having 7 unpaired electrons.

Magnetic moment $(\mu )=\sqrt{n(n+2)}B.M$

$\mu =\sqrt{7(7+2)}B.M.$

$=7.9B.M$

$n\Rightarrow$ Number of unpaired electrons