What are Van der Waals forces?

Van der Waals forces refer to the weak intermolecular forces that occur between molecules. These forces arise due to temporary dipoles that occur when electrons are distributed unevenly around molecules at any given moment. These interactions can be significant in systems where molecules are close together, influencing properties such as boiling and melting points, viscosity, and solubility.

Intermolecular forces encompass various types of attractions, including London dispersion forces (which are a type of Van der Waals forces), dipole-dipole interactions, and hydrogen bonds. Therefore, recognizing Van der Waals forces as a subset of intermolecular forces is essential in understanding molecular interactions in different substances.

In contrast, the other choices describe different types of bonding or forces. Intra-molecular forces refer to interactions occurring within a single molecule, such as covalent or ionic bonds, and are generally much stronger than intermolecular forces. Hydrogen bonds, while they do involve intermolecular interactions, represent a specific type of dipole-dipole interaction rather than a broader category of forces that includes all weaker van der Waals interactions. Lastly, covalent bonding forces are strong forces that hold atoms together within a molecule, rather than influencing interactions between separate molecules.