MCQ
The pair of lanthanides in which both elements have high third-ionization energy is:
- A$Eu , Gd$
- ✓$Eu , Yb$
- C$Lu , Yb$
- D$Dy, Gd$
✓
Answer
Correct option: B.
$Eu , Yb$
b
$\left.Eu ^{+2}:[ Xe ] 4 f ^7\right\}$ High IE due to half
$\left.Eu ^{+2}:[ Xe ] 4 f ^7\right\}$ High IE due to half
$\left.Yb ^{+2}:[ Xe ] 4 f ^{14}\right\}$ filled \& fully filled configurations
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