Question

1. based on their positions in the periodic table, predict which has the largest atomic radius: li, rb, n, f, i.

Explanation:

Step1: Recall atomic radius trends

Atomic radius generally increases down a group (due to adding electron shells) and decreases across a period (due to increasing nuclear charge pulling electrons closer).

Step2: Classify elements by group/period

• Li (lithium) and Rb (rubidium) are in Group 1 (alkali metals). Rb is below Li, so Rb has a larger radius than Li.
• N (nitrogen) and F (fluorine) are in Period 2, Group 15 and 17 respectively. N has a larger radius than F (across period decrease).
• I (iodine) is in Group 17, below F.

Step3: Compare Group 1 and others

Group 1 metals (Li, Rb) have larger radii than Group 15/17 non - metals (N, F, I) because metals have more electron shells in the same period context and down - group trends. Among Li and Rb, Rb is lower in Group 1, so it has more electron shells.

Step4: Confirm Rb's radius

Rb has electron configuration with more shells than Li, N, F, and I. So Rb's atomic radius is the largest among the given elements.

Answer:

Rb