Question

Gd$(64)$ has _____ unpaired electrons with sum of spin _____

• A. 7, 3.5
• B. 44776
• C. 44715
• D. 44777

Answer 1

Answer: (D)

44777

Answer 2

The element $Gd (Z=64)$ show electronic configuration $=[ Xe ]_{54} \cdot 4 f^{7}, 5 d^{1}, 6 s^{2}$

Thus, it has 8-unpaired electrons $\left(4 f^{7}\right.$ and $\left.6 d^{1}\right)$ and its sum of spin is 4 .