4.1: Compounds, Lewis Diagrams and Ionic Bonds 4.2: Nomenclature of Ionic Compounds 4.3: Covalent Bonding 4.4: Exceptions to the Octet Rule 4.5: Nomenclature of Molecular Compounds 4.6: Electronegativity and the Polar Covalent Bond 4.7: Intermolecular Forces All substances experience dispersion forces between their particles. Substances that are polar experience dipole-dipole interactions. Substances with covalent bonds between an H atom and N, O, or F atoms experience hydrogen bonding. The preferred phase of a substance depends on the strength of the intermolecular force and the energy of the particles.