9.3 Polarity and Intermolecular Forces
9.3 Polarity and Intermolecular Forces
Lesson Objectives
- Describe how the electronegativity difference between two atoms in a covalent bond results in the formation
of a nonpolar covalent, polar covalent, or ionic bond. - Describe how molecular geometry plays a role in determining whether a molecule is polar or nonpolar.
- Distinguish between the following three types of intermolecular forces: dipole-dipole forces, London disper-
sion forces, and hydrogen bonds. - Describe how chemical bonding and intermolecular forces influence the properties of various compounds.
Lesson Vocabulary
- diatomic element
- dipole
- dipole-dipole forces
- hydrogen bond
- intermolecular forces
- London dispersion forces
- nonpolar covalent bond
- polar covalent bond
- polar molecule
- van der Waals forces
Check Your Understanding
Recalling Prior Knowledge
- How do electrons behave during the formation of an ionic bond, and what properties of ionic compounds
result from the bonding? - What is meant by the electronegativity of an element?
In an ionic bond, one or more electrons are transferred from one atom to another. In a covalent bond, one or more
pairs of electrons are shared between atoms. However, bonding between atoms of different elements is rarely purely
ionic or purely covalent. The true nature of a chemical bond often falls somewhere in between these two extremes.