Question

There is considerable increase in covalent radius from N to P. However, from Sb to Bi only small increase (of 7 pm) in covalent radius is observed. This is due to
A. poor shielding by completely filled d-and f-orbitals in Bi
B. similar electronegativity of Sb and Bi
C. the Bi being last element of the group
D. similar densities of Sb and Bi

Answer 1

Correct Answer - A
Poor shielding by `f-` and d-electrons enhences the effective nuclear charge in Bi. This causes contraction in size.