Question

Which of the following is paramagnetic in nature?

• A. Lu${}^{3+}$
• B. Ce${}^{4+}$
• C. Eu${}^{2+}$
• D. Yb${}^{2+}$

Answer 1

The correct option is C Eu${}^{2+}$

Lanthanoids exhibit f 0 $\left(C{e}^{4+}\right)$ and the f 14 (Yb${}^{2+}$ and Lu${}^{3+}$ ) configurations with no unpaired electron, thus, they are diamagnetic, whereas, Eu${}^{2+}$exhibits f7 configuration with seven unpaired electrons.