Which of the following atoms would be expected to have the largest atomic radii?

Question

Canvas Classes · Accepted Answer

Strategy:
 Compare elements based on the number of electron shells (Group trend) and nuclear charge (Period trend). More shells always result in a larger radius.

Step 1: Locate elements in the table
- O (Oxygen): Period 2, Group 16 ( shells).
- Mg (Magnesium): Period 3, Group 2 ( shells).
- Al (Aluminum): Period 3, Group 13 ( shells).
- Ca (Calcium): Period 4, Group 2 ( shells).

Step 2: Rank
- Period 4 elements are larger than Period 3.
- Calcium (), being in the  period and in an early group

More questions from Classification of Elements and Periodicity