Question

Arrange the following elements in increasing order of their size.

V, Nb, Ta, Db

• A. V < Nb $=$ Ta $\approx$ Db
• B. Db < Nb $=$ Ta $\approx$ V
• C. Ta < Nb $=$ V $\approx$ Db
• D. None of these

Answer 1

The correct option is A V < Nb $=$ Ta $\approx$ Db

Down the group, size increases due to the addition of a new shell. As there is an addition of new shell, poor shielding of d and f orbitals and the increased charge on centre nullifies the effect.

Hence, the correct order will be - $V<Nb=Ta\approx Db$.