Which of the following pairs has the same size? | Chemistry | SolveeIt

Question

Which of the following pairs has the same size?

$Fe^{2+},Ni^{2+}$

$Zr^{4+},Ti^{4+}$

$Zr^{4+},Hf^{4+}$

$Zn^{2+},Hf^{4+}$

Answer

$Zr^{4+},Hf^{4+}$

Explanation

Solution

In general, the atomic and ionic radii increases on moving down a group but the elements of second transition series $(Zr, Nb, Mo)$ have almost same radii as the elements of third transition series $(Hf, Ta, W, etc)$ . This is because of lanthanoid contraction, i.e.
imperfect shielding of one $4f\, e^-$ by another.

Chemistry Question on d -and f -Block Elements

Solution