Which statement best describes London dispersion forces?

• A. They are temporary attractive forces resulting from instantaneous dipoles in molecules.
• B. They arise from hydrogen bonding between molecules.
• C. They are the strongest type of intermolecular force present in water.
• D. They occur only between polar molecules with permanent dipoles.

Answer: (A)

Verified step by step guidance

1. Understand that London dispersion forces are a type of intermolecular force that arise due to temporary fluctuations in electron distribution within molecules or atoms.
2. Recognize that these fluctuations create instantaneous dipoles, which induce dipoles in neighboring molecules, leading to a temporary attractive force.
3. Note that London dispersion forces are present in all molecules, whether polar or nonpolar, but are the only intermolecular forces in nonpolar molecules.
4. Distinguish London dispersion forces from other intermolecular forces such as hydrogen bonding, which involves specific interactions between hydrogen and highly electronegative atoms like oxygen, nitrogen, or fluorine.
5. Conclude that London dispersion forces are generally weaker than hydrogen bonds and dipole-dipole interactions but are crucial for understanding the behavior of nonpolar substances.