Question

Why atomic radius goes on decreasing while going from left to right wing within a period

Answer 1

atomic radius decrease while going across a period because valence electrons are being added to the same energy level at the same time the nucleus is increasing in protons. and increase in effective nuclear charge attracts the electrons more strongly thus making the atomic radius decrease.

hope it helps you

Answer 2

because the electron are added to same shell due to this they experiance a great force from the nucleus