Which of the following pairs has the same size ?

Options

A. `Zn^(2+)` , `Hf^(4+)`
B. `Fe^(2+)` , `Ni^(2+)`
C. `Zr^(4+)` , `Ti^(4+)`
D. `Zr^(4+)` , `Hf^(4+)`

Answer

D

Explanation

One of the consequences of the lanthanoid contraction is that the second anf third d series elements exhibit similar atomic and ionic radii and have very similar physical and chemical properties much more than that expected on the basis of usual family relationship.