[Xylene]

I have heard that, In general as we go across the period in the periodic table,the nuclear charge increases so attraction between the nucleus and the outermost electrons increases and the atomic size goes on decreasing, but my doubt is as protons are added, electrons are also added and the atom has same number of protons as the electrons so the size of all the elements should be same.

THANKS

[ramboacid]

Remember that there are shielding effects though that protect electrons in the valence layer. Thus, the electrons in elements at the beginning of a period are farther away from the nucleus. As the nuclear charge grows, new electrons are added to the same layer, and thus the attraction increases because the charge grows but the distance is between the electrons and the nucleus is constant. This causes the atomic radius to decrease across a period.

[Xylene]

so is it like when electrons are added to the same shell and when the nuclear charge increases, the attraction between them increases?
I dont understand how the attraction increases as the electron is added,infact it should remain the same 

[fledarmus]

Do you know how the attractive force between two particles is related to their charge and to the distance between them?