Question:
The $\mathrm{Eu}^{2+}$ ion is a strong reducing agent in spite of its ground state electronic configuration
(outermost): [Atomic number of Eu =63]
Correct Option: 3,
Solution:
$\mathrm{Eu} \rightarrow[\mathrm{Xe}] 4 \mathrm{f}^{7} 6 \mathrm{~s}^{2}$
$\mathrm{Eu}^{2+} \rightarrow[\mathrm{Xe}] 4 \mathrm{f}^{7}$