Chemistry

Question Analysis
This question assesses the student's ability to identify the element with the largest atomic radius within a specific period.

Key Concept Explanation
Atomic radius generally decreases as you move from left to right across a period due to the increasing nuclear charge pulling valence electrons closer to the nucleus.

Step-by-step Solution
1. Identify the elements in Period 3: Na, Mg, Al, Si, P, S, Cl, Ar.
2. Recall the trend for atomic radius across a period: atomic radius decreases ...