Chemistry

Question Analysis
This question tests the student's ability to identify the element with the smallest atomic radius in a specific period.

Key Concept Explanation
In Period 4, the element with the smallest atomic radius is Krypton(Kr) because it is located farthest to the right in the period, where the atomic radius is minimized due to the increasing nuclear charge.

Step-by-step Solution
1. Identify the elements in Period 4.
2. Recall the trend in atomic radius across a period (decreases from left to right).
3. Locate