Question

How does atomic size vary in the periodic table?

Answer 1

In groups from top to bottom - Atomic size increases and in periods from left to right - Atomic size decreases .

Explanation:

When you are going down the periodic table , the new electrons get filled into new shells which make them farther and farther from the nucleus and thus , Atomic size decreases .

When you are going from left to right , the electrons get filled into the same shell and due to more attractions between electrons and protons the shells tend to come closer to the nucleus and thus , Atomic size decreases .