Question

Which of the following ions contains minimum number of unpaired electrons?

• A. $Fe^{2 +}$
• B. $Fe^{3 +}$
• C. $Co^{2 +}$
• D. $Co^{3 +}$

Answer 1

Answer: (C)

$Co^{2 +}$

Answer 2

: $Fe^{2 +}(z = 26)\lbrack Ar\rbrack 3d^{6}$ - 4 unpaired electrons

$Fe^{3 +}\lbrack Ar\rbrack 3d^{5}$ - 5 unpaired electrons

$Co^{2 +}(z = 27)\lbrack Ar\rbrack 3d^{7}$ - 3 unpaired electrons

$Co^{3 +}\lbrack Ar\rbrack 3d^{6}$ - 4 unpaired electrons