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