Question

Which of the following has maximum unpaired electrons?

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

Answer 1

Answer: (B)

$Sc(Z=21):[Ar{]}^{18}4s^{2}3d^1$ (1 unpaired electron)
$Cr(Z=24):[Ar{]}^{18}4s^{1}3d^5$ (6 unpaired electrons)
$Mn(Z=25):[Ar{]}^{18}4s^{2}3d^5$ (5 unpaired electrons)
$Fe(Z=26):[Ar{]}^{18}4s^{2}3d^6$ (4 unpaired electrons)
Chromium has maximum number of unpaired electrons