The correct order of ionic radii `Y^(3+)` , `La^(3+)` , `Eu^(3+)` and `Lu^(3+)` is `(AT. No : Y = 39, La = 57, Eu = 63, Lu = 71)`

Options

A. `La^(3+) lt Eu^(3+) lt Lu^(3+) lt Y^(3+)`
B. `Y^(3+) lt La^(3+) lt Eu^(3+) lt Lu^(3+)`
C. `Lu^(3+) lt Y^(3+) lt Eu^(3+) lt La^(3+)`
D. `Lu^(3+) lt Eu^(3+)ltLa^(3+) lt Y^(3+)`

Answer

C

Explanation

Lanthanide contraction results in small size of `Lu^(3+)`, so `Lu^(3+) lt Y^(3+) lt Eu^(3+) lt La^(3+)`.