How does atomic radius change as you move down a group in the periodic table?

• A. Atomic radius increases.
• B. Atomic radius first increases, then decreases.
• C. Atomic radius remains constant.
• D. Atomic radius decreases.

Answer: (A)

Verified step by step guidance

1. Understand that atomic radius refers to the average distance from the nucleus of an atom to the outermost electrons.
2. Recognize that as you move down a group in the periodic table, each successive element has an additional electron shell compared to the one above it.
3. Realize that adding more electron shells increases the distance between the nucleus and the outermost electrons, which tends to increase the atomic radius.
4. Consider that although the nuclear charge increases down the group, the effect of increased electron shielding from inner shells reduces the effective nuclear attraction on the outer electrons.
5. Conclude that due to the addition of electron shells and shielding effect, the atomic radius increases as you move down a group in the periodic table.