The correct order of ionic radii of Ce, La, Pm and Yb in+3 oxidation state is:

Options

A. `La^(3+) lt Pm^(3+) lt Ce^(3+) lt Yb^(3+)`
B. `La^(3+) lt Ce^(3+) lt Pm^(3+) lt Yb^(3+)`
C. `Yb^(3+) lt Ce^(3+) lt Pm^(3+) lt La^(3+)`
D. `Yb^(3+) lt Pm^(3+) lt Ce^(3+) lt La^(3+)`

Answer

D

Explanation

Lanthanide contraction decreases atomic size from `La^(3+) " to " Lu^(3+)`. Hence the correct order will be (D) for the given ions. .