Which of the following metals would be predicted to have the smallest atomic radius?

• A. K
• B. Rb
• C. Li
• D. Na

Answer: (C)

Verified step by step guidance

1. Recall that atomic radius generally increases as you move down a group (column) in the periodic table because additional electron shells are added, increasing the size of the electron cloud.
2. Identify the group to which the metals belong. K (potassium), Rb (rubidium), Na (sodium), and Li (lithium) are all alkali metals in Group 1 of the periodic table.
3. Compare their positions in the group: Li is at the top, followed by Na, then K, and finally Rb at the bottom.
4. Since atomic radius increases down the group, the element at the top (Li) will have the smallest atomic radius because it has the fewest electron shells.
5. Therefore, predict that Li has the smallest atomic radius among the given metals based on its position in the periodic table.