Question

The atomic radius of main-group elements generally increases down a group because ________. A) effective nuclear charge decreases down a group B) effective nuclear charge zigzags down a groupC) the principal quantum number of the valence orbitals increases D) effective nuclear charge increases down E) a group both effective nuclear charge increases down F) a group and the principal quantum number of the valence orbitals increases

Answer 1

D) effective nuclear charge increases down

When nuclear charge increases, the atomic radius gets smaller because the electrons are being pulled more strongly and therefore closely to the nucleus