Question

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)`
A. `Y^(3+)ltLa^(3+)ltEu^(3+)ltLu^(3+)`
B. `Y^(3+)ltLu^(3+)ltEu^(3+)ltLa^(3+)`
C. `Lu^(3+)ltEu^(3+)ltLa^(3+)ltY^(3+)`
D. `La^(3+)ltEu^(3+)ltLu^(3+)ltY^(3+)`

Answer 1

Correct Answer - B
(b) The element Y is a transition metal (4d-series) while the rest are lanthanoids.
`Y^(3+)` has the smallest size. For the rest, the size decreases along a period.