Which one of the following lanthanic ions does not exhibit paramagnetism ?

Options

A. `Lu^(3+)`
B. `Ce^(3+)`
C. ` Cu^(3+)`
D. `Yb^(3+)`

Answer

(a)

Explanation

Paramagnetism depend upon number of unpaired `e^-s` since ` Lu^3+ - 4f^14` has no unpaired `e^-s`, it does not exhibit paramagnetism .