Question

multiple choice 1 point
put the following elements in order from largest to smallest atomic radius:
p, cl, s, ar
○ ar, cl, s, p
○ p, cl, s, ar
○ cl, p, s, ar
○ p, s, cl, ar

Explanation:

Step1: Recall atomic radius trend

In a period (row) of the periodic table, atomic radius generally decreases from left to right. This is because as we move right, the number of protons increases, pulling electrons closer to the nucleus, while the number of electron shells remains the same.

Step2: Identify the period of the elements

Phosphorus (P), Sulfur (S), Chlorine (Cl), and Argon (Ar) are all in Period 3 of the periodic table.

Step3: Determine the order from left to right

In Period 3, the order from left to right is P (Group 15), S (Group 16), Cl (Group 17), Ar (Group 18).

Step4: Apply the atomic radius trend

Since atomic radius decreases from left to right in a period, the order from largest to smallest atomic radius is P (largest), then S, then Cl, then Ar (smallest).

Answer:

P, S, Cl, Ar (the last option: P, S, Cl, Ar)