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

Options

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

Answer

D

Explanation

Lanthanoid ion with no unpiared electronis diamagnetic in nature.
`Ce_(58) =[Xe]4f^(2)5d^(0)6s^(2)`
`Ce^(2+) =[Xe]4f^(2)` (two unpaired electrons)
`Sm_(62) = [Xe]4f^(6)5d^(0)6s^(2)`
`Sm^(2+) = [Xe]4f^(6)` (six unpaired electrons)
`Eu_(63) =[Xe]4f^(6)5d^(0)6s^(2)`
`Eu^(2+) =[Xe]4f^(7)` (seven unpiared electrons)
`Yb_(70)=[Xe]4f^(14)5d^(0)6s^(2)`
`Yb^(2+) = [Xe]4f^(14)` (no unpaired electrons)
Because of the absence of unpaired electrons, `Yb^(2+)` is diamagnetic.