Question

What happens to the atomic size of the elements as one goes from the bottom to the top of a group?

Responses

Atomic size stays the same as one moves from bottom to top in a group.

Atomic size stays the same as one moves from bottom to top in a group.

Atomic size changes randomly as one moves from bottom to top in a group.

Atomic size changes randomly as one moves from bottom to top in a group.

Atomic size decreases as one moves from bottom to top in a group.

Atomic size decreases as one moves from bottom to top in a group.

Atomic size increases as one moves from bottom to top in a group.

Atomic size increases as one moves from bottom to top in a group.

Answer 1

Atomic size decreases as one moves from the bottom to the top of a group.

Reason: moving upward removes electron shells (lower principal quantum number) and increases the effective nuclear attraction on the valence electrons, pulling them closer to the nucleus and reducing atomic radius.