Question:

The correct electronic configuration and spin-only magnetic moment (BM) of \(\mathrm{Gd^{3+}}\) (\(Z = 64\)), respectively, are :

Show Hint

Gd is a lanthanoid, so electrons fill 4f. Gd3+ has seven unpaired electrons; use \(\sqrt{n(n+2)}\).
Updated On: Nov 5, 2026
  • \(\mathrm{[Xe]5f^7}\) and 8.9
  • \(\mathrm{[Xe]4f^7}\) and 7.9
  • \(\mathrm{[Xe]5f^7}\) and 7.9
  • \(\mathrm{[Xe]4f^7}\) and 8.9
Show Solution
collegedunia
Verified By Collegedunia

The Correct Option is B

Solution and Explanation

Gd (Z = 64) has the configuration \(\mathrm{[Xe]4f^7 5d^1 6s^2}\).
Gd3+ loses 3 electrons (6s2 and 5d1): \(\mathrm{[Xe]4f^7}\). Lanthanoids fill the 4f subshell, so 5f is not correct.
Seven unpaired electrons: \(\mu = \sqrt{n(n+2)} = \sqrt{7\times 9} = \sqrt{63} = 7.94 \approx 7.9\) BM.
Answer: (2) \(\mathrm{[Xe]4f^7}\) and 7.9
Was this answer helpful?
0
0