Although Zirconium belongs to the 4d transition series and Hafnium to 5d transition series even then they show similar physical and chemical properties because___________.
(i) both belong to d-block.
(ii) both have the same number of electrons.
(iii) both have a similar atomic radius.
(iv) both belong to the same group of the periodic table
The answer is the option (iii). Zirconium and hafnium show similar physical and chemical properties due to the almost identical radii of and . Similar atomic radius results from lanthanoid contraction.