effective nuclear charge

Effective nuclear charge is the net positive force experienced by an electron in an atom. It’s the balance between the attractive pull of the nucleus (protons) and the repulsive effects of other electrons. While the nucleus’s full positive charge attracts electrons, inner electrons shield outer electrons from this pull, reducing the net attraction. Therefore, as you go further from the nucleus or add more protons, the effective nuclear charge increases, pulling electrons more strongly. This concept helps explain trends in atomic size, ionization energy, and electron behavior across different elements.