`Eu^(3+)` ion is isoelectronic with

Options

A. `Ce ^(4+)`
B. `Yb ^(2+)`
C. `Eu ^(4+)`
D. `Sm^(2+)`

Answer

D

Explanation

We know that, the species which contains same number of valence electrons are isoelectronic. `Eu^(3+) and Sm^(2+)` have same configuration`6s^(0), 4f^(6), 5d^(0).` Hence these are isoelectronic.