challenge question (bonus) 21. explain why francium (fr) is expected to have the largest atomic radius of…

Brief Explanations:

Atomic radius increases down a group and decreases across a period. Francium is in Group 1 (alkali metals), the last - naturally occurring element in the group. As we move down Group 1, the number of electron shells increases, and the outermost electrons are further from the nucleus, resulting in a larger atomic radius compared to other elements.

Answer:

Francium is in the lowest position of Group 1. As we move down a group in the periodic table, the number of electron shells increases, causing the outermost electrons to be farther from the nucleus and resulting in a larger atomic radius than other elements.