Factors Affecting Periodicity Periodic Trends: •Atomic Radius: the distance from the center of the nucleus to the outermost electron (how big an atom is) –Ionic Radius: the size of positive or negative ions •Ionization energy: the amount of energy required to remove an electron from an atom or ion •Electronegativity: the attraction an atom has for electrons Factors Affecting Periodicity Factors Affecting Periodicity: •Effective Nuclear Charge: the total positive force of the nucleus (the more protons, the higher the effective nuclear charge) •Electron Repulsion: result of likecharged electrons electrostatic repulsion Factors Affecting Periodicity •Stable electron configuration: atoms strive to form s2p6 configurations (full valence*, full octet*…*we’ll get to this) •Number of Energy Levels •Electron Shielding Effect: inner electrons temporarily “blocking” the nucleus’s electrostatic attraction for outer electrons •Proton : electron ratio