MCQ
Identify a 'Chemical twin' among the followings.
- A$Zr - Ta$
- B$Nb - Tc$
- C$Hf - Re$
- ✓$Nb - Ta$
✓
Answer
Correct option: D.
$Nb - Ta$
Chemical twins are those in which the properties of some elements are same. Atomic size of $Zr$ and $\text{Hf , Nb}$ and $Ta$ are similar. This is due to lanthanide contraction.
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