Which atom in each group (I and II)has the smallest atomic radius?
(I)Ba,Hf,At
(II)As,Sb,Bi
A)Ba;As
B)Ba;Bi
C)At;As
D)At;Bi

Question

Which atom in each group (I and II)has the smallest atomic radius?
(I)Ba,Hf,At 
(II)As,Sb,Bi
A)Ba;As
B)Ba;Bi
C)At;As
D)At;Bi

Quizplus · Accepted Answer

In group I, At has the smallest atomic radius because it has the highest atomic number and strongest nuclear charge, which attracts the electrons more strongly, leading to a smaller atomic radius. Among Ba and Hf, Ba has the largest atomic radius because it has one less proton in its nucleus compared to Hf, and thus its electrons experience less nuclear attraction.
In group II, As has the smallest atomic radius because it has the highest nuclear charge and attracts its electrons more strongly than Sb and Bi, which have more electron shielding due to their larger size. Among Sb and Bi, Bi has the larger atomic radius because it has more electron shielding and less nuclear attraction compared to Sb.

Which Atom in Each Group (I and II)has the Smallest