Question
Chemistry Question on d -and f -Block Elements
Because of lanthanoid contraction, which of the following pairs of elements have nearly same atomic radii? (Numbers in the parenthesis are atomic numbers)
A
Zr(40) and Hf (72)
B
Zr (40) and Ta (73)
C
Ti (22) and Zr (40)
D
Zr (40) and Nb (41)
Answer
Zr(40) and Hf (72)
Explanation
Solution
Due to lanthanide contraction ?4d? and ?5d? series of elements have almost same atomic radii.