5-3: Periodic Trends

Atomic Radius Size of atom from center of nucleus to outermost electron Increases as you move down a family Decreases as you move left to right

Ionic Size When an atom loses electrons, it gets smaller When an atom gains electrons, it gets bigger

Ionization Energy The energy needed to remove an atom’s electrons. The higher the ionization energy the more tightly an atom is holding onto its electrons. It decreases as you move down a group. It increases as you move to the right.

Successive Ionization Energies Energy required to remove further electrons

Electron Affinity The energy change that occurs when an atom gains an extra electron. The greater the EA, the more the atom wants or has an affinity for electrons. EA increases as you move from left to right (except noble gases). It decreases as you move down the table.

Electronegativity At atom’s ability to attract electrons. It increases as you move from left to right (except for noble gases). It decreases as you move down the table. Fluorine is the most electronegative element.