How do atomic radii change as you move from the top to the bottom of a group in the periodic table?

• A. Decrease
• B. First decrease, then increase
• C. Increase
• D. Remain the same

Answer: (C)

Verified step by step guidance

1. Understand that atomic radius refers to the size of an atom, typically measured as the distance from the nucleus to the outermost electron cloud.
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. Recall that adding more electron shells increases the distance between the nucleus and the outermost electrons, which tends to increase the atomic radius.
4. Consider the effect of shielding, where inner electron shells reduce the effective nuclear charge felt by outer electrons, allowing the outer electrons to be held less tightly and thus increasing atomic size.
5. Conclude that because of the addition of electron shells and increased shielding, atomic radii generally increase as you move from the top to the bottom of a group in the periodic table.