Question

Which of the following transition metal ions has highest magnetic moment?

• A. $Cu^{2 +}$
• B. $Ni^{2 +}$
• C. $Co^{2 +}$
• D. $Fe^{2 +}$

Answer 1

Answer: (D)

$Fe^{2 +}$

Answer 2

More the unpaired d-electrons, more is the magnetic moment.

$Cu^{2 +} - 3d^{9}$ No. of unpaired electrons = 1

$Ni^{2 +} - 3d^{8}$ No. of unpaired electrons = 2

$Co^{2 +} - 3d^{7}$ No. of unpaired electrons = 3

$Fe^{2 +} - 3d^{6}$ No. of unpaired electrons = 4