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 unpaired electron is diamagnetic in nature. `Ce_(58)=[Xe]4f^(2),5d^(0),6s^(2)``Ce^(2+)=[Xe]4f^(2)` (Two unpaire electrons)
`Sm_62=[Xe]4f^(6),5d^(0),6s^(2)`
`Sm^(2+)=[Xe]4f^(6),5d^(0)` (Six unpaired electrons)
`Eu_(63)=[Xe]4f^(7),5d^(0),6s^(2)`
`Eu^(2+)=[Xe]4f^(7),5d^(0)`(Seven unpaired electrons)`
Yb_(70)=[Xe]4f^(14),5d^(2)`
`Yb^(2+)=[Xe]4f^(14),5d^(0)`(No unpaired electron)
since, `Yb^(2+)` has no unpaired electron, so it is a diamagnetic ion