Question

which element will have the smallest atomic radius? phosphorus (p) sulfur (s) silicon (si) aluminum (al)

Explanation:

Step1: Recall atomic - radius trend

Atomic radius decreases across a period from left to right due to increasing nuclear charge attracting electrons more strongly.

Step2: Identify elements' positions

Al, Si, P, and S are in the same period (period 3). Al is the left - most, followed by Si, then P, and S is the right - most among them.

Answer:

S. sulfur (S)