Forming Ions: Making Satisfying Electron Trades

In nature, achieving a filled (complete) valence energy level is a driving force of chemical reactions, because when that energy level is full, elements become stable, or “satisfied” — stable elements don’t lose, gain, or share electrons. The noble gases — the VIIIA elements on the periodic table are extremely nonreactive because their valence energy level (outermost energy level) is filled. However, the other elements in the A families on the periodic table do gain, lose, or share valence electrons to fill their valence energy level and become satisfied.

Because filling the valence energy level usually involves filling the outermost s and p orbitals, it’s sometimes called the octet rule — elements gain, lose, or share electrons to reach a full octet (eight valence electrons: two in the s orbital and six in the p orbital).