Texas A&M University (TAMU) CHEM 222 Elements of Organic and Biological Chemistry Exam 1 Practice

Electronegativity difference controls how electrons are shared in a bond. When two nonmetals bond, electrons are shared rather than transferred. If the difference in electronegativity is relatively large, the shared electrons are pulled closer to the more electronegative atom, creating partial charges on each atom. That gives a polar covalent bond.

Ionic bonds arise from complete electron transfer and are most typical between metals and nonmetals, not two nonmetals. Metallic bonds involve a lattice of metal atoms sharing a sea of electrons. So, for two nonmetals with a sizable electronegativity difference, the bond is best described as polar covalent.