Question

Which of the following has the same number of unpaired electrons as are present in samarium?

• A. Scandium
• B. Chromium
• C. Manganese
• D. Iron

Answer 1

Answer: (B)

The electronic configuration of samarium is as:
$Sm(Z=62):[Xe]6s^{2}4f^6$
Number of unpaired electron $=6$
The electronic configuration of chromium is as:
$Cr(Z=24):[Ar]3d^{5}4s^1$
Number of unpaired electrons $=6$
Hence, $Sm$ and $Cr$ both have same number of unpaired electrons.