Atomic number of Mn. Fe and Co are 25, 26 and 27 respectively. Which of the following inner orbital octahedral complex ions are diamagnetic ?

Options

A. `[Co(NH_(3))_(6)]^(3+)`
B. `[Mn(CN)_(6)]^(3-)`
C. `[Fe(CN)_(6)]^(3-)`
D. None of the above

Answer

A

Explanation

Molecular orbital electronic configuration of `Co^(3+)` in `[Co(NH_(3))_(6)]^(3+)` is

Number of unpaired electron = 0
Magnetc property = Diamagnetic