how does the atomic number affect the atomic radius?

Answer 1

The greater the atomic number, the greater the number of protons in the nucleus, which USUALLY means a higher number of neutrons and electrons. The greater number of particles (protons, neutrons, and electrons) the greater the atomic radius.

Note: There are different answers to this question depending upon what level of chemistry you are taking. But if you're taking a basic chemistry, it's the right answer.