Question

The correct order of atomic radii is:
A. `Yb^(3+) lt P m^(3+) lt Ce^(3+) lt La^(3+)`
B. `Ce^(3+) lt Yb^(3) lt P m^(3+) lt La^(3+)`
C. `Yb^(3+) lt P m^(3+) lt La^(3+) lt Ce^(3+)`
D. `P m^(3+) lt La^(3+) lt Ce^(3+) lt Yb^(3+)`

Answer 1

Correct Answer - A
Due to lanthanoid contraction
Ionic radius
`underset(86)(._(70)Yb^(3+)) lt underset(98)(._(61)Pm^(3+)) lt underset(103)(._(58)Ce^(3+)) lt underset(106 " pm")(._(57)La^(3+))`