Question

Why do zirconium and Hafnium exhibit similar properties?

Answer 1

1. The element of the second and third transition series resemble each other more closely than the elements of the first and second transition series due to lanthanoid contraction.
2. e.g., Zr – 4d series -Atomic radius 145 pm Hf – 5d series – Atomic radius 144 pm
3. The radii are very similar even though the number of electrons increases.
4. Zr and Hf have very similar chemical behaviour, having closely similar radii and electronic configurations.
5. Radius-dependent properties such as lattice energy, solvation energy are similar.
6. Thus lanthanides contraction leads to the formation of pair of elements and those known as chemical twins, e.g., Zr – Hf