Question

which has the largest atomic radius? *
li
ca
n
f
i
how can i(your teacher) help you (the student) learn better? *

Explanation:

Atomic radius trends: increases down a group (more electron shells) and decreases across a period (increased nuclear charge pulls electrons closer). Li (lithium) is in period 2, N (nitrogen) and F (fluorine) in period 2 (smaller than period 4/5 elements). Ca (calcium) is in period 4, I (iodine) in period 5. But group 2 (Ca) has larger radius than group 17 (I) in their respective periods. Comparing Ca (period 4, group 2) and I (period 5, group 17), Ca has a larger atomic radius as the effect of period number increase is offset by group - based electron - shell and nuclear charge balance (Ca has fewer protons pulling on its outer electrons compared to I in a higher group).

Answer:

Ca