Chemistry

Question Analysis
This question involves identifying an element with a smaller atomic radius than a given reference element (sulfur).
The main focus is on applying both period and group trends of atomic radius to compare multiple elements.

Key Concept Explanation
Period trend: Atomic radius decreases from left to right across a period due to increasing nuclear charge.
Group trend: Atomic radius increases from top to bottom down a group due to additional electron shells.

Step-by-Step Solution
1. Locate sulfur (S) in the periodic table: Period 3, Group 16.
2. Analyze each option:
A. P: Period 3, Group 15 (left of S) → larger radius than S.
B. Cl: Period 3, Group 17 (right of S) → smaller radius than S.
C. Se: Group 16, Period 4 (below S) → larger radius than S.<...