A Level Chemistry OCR Practice Exam

What is an intermolecular force?

1. A force between nuclei in an atom

2. An attractive force between neighboring molecules

3. A repulsive force between ions

4. A force that occurs only in ionic compounds

The correct answer is: An attractive force between neighboring molecules

An intermolecular force is defined as an attractive force that exists between neighboring molecules. These forces are responsible for various physical properties of substances, such as boiling points, melting points, and the behavior of gases, liquids, and solids. Understanding intermolecular forces is crucial because they influence how different substances interact with one another and their states of matter. The concept of intermolecular forces encompasses various types, including hydrogen bonds, dipole-dipole interactions, and London dispersion forces, which collectively contribute to a substance's overall behavior. While intermolecular forces play a significant role in molecular interactions, they differ from intramolecular forces, which are the forces that hold atoms together within a molecule. In contrast, the other options focus on forces that are not classified as intermolecular. For example, the force between nuclei in an atom pertains to intramolecular forces, while repulsive forces between ions and forces exclusive to ionic compounds do not encompass the broader category of forces acting between molecules.