Which of the following lanthanoid ions is diamagnetic? (Atomic number of `Ce=58,Sm=62,Eu=63,Yb=70`]

Options

A. `Sm^(2+)`
B. `Eu^(2+)`
C. `Yb^(2+)`
D. `Ce^(2+)`

Answer

C

Explanation

`Ce (4f^(1) 5d^(1) 6s^(2)) rarr Ce^(2+) (4f^(1) 5d^(1))`
`Sm (4f^(6) 6s^(2)) rarr Sm^(2+) (4f^(6))`
`Eu(4f^(7) 6s^(2)) rarr Eu^(2+) (4f^(7))`
`Yb (4f^(14) 6s^(2)) rarr Yb^(2+) (4f^(14))`
`Yb^(2+)` is dimagetic as there is no unpaired electron due to completely full 4f subshell.