Question

How does the atomic size vary in a period with increase in atomic number?

Answer 1

While going from left to right in a period, atomic no. Increases thus positive charge in nucleus increases by one unit. However additional electrons are added to the same orbit and thus nuclear charge is increased. Due to increased nuclear charge the electrons are pulled with a greater force and hence atomic size decrease

Answer 2

as we go from left to right in a period the atomic no. increases by one unit....since the electron gets added to the same outermost shell....the electrons experience a strong nuclear force from the nucleus and the shell moves towards the nucleus and thus the atomic size decreases.....the more electrons in the outermost shell in a period the less will the atomic size

hope this helps...