Question

the circle on the left is a representation of the size of a chlorine, cl, atom. based on this image, which of the circles best represents an atom of argon, ar?

Explanation:

Chlorine and argon are in the same period. Atomic - size generally decreases across a period from left to right due to an increase in effective nuclear charge. Argon is to the right of chlorine in the periodic table, so it has a smaller atomic radius than chlorine. Circle A is the smallest among the given circles.

Answer:

Circle A