Humber Admissions Practice Test

What are intermolecular forces?

1. Forces holding ions in a crystal lattice

2. Forces that act within a single molecule

3. Forces of attraction between molecules

4. Forces that repel electrons

The correct answer is: Forces of attraction between molecules

Intermolecular forces are defined as the forces of attraction that occur between molecules. These forces are crucial for determining the physical properties of substances, such as boiling points, melting points, and solubility. Intermolecular forces help hold different molecules together in various states of matter, influencing how they interact with one another. The correct choice highlights this attraction between separate molecules, which is distinct from forces acting within a single molecule, such as covalent or ionic bonds. Such internal forces are not categorized as intermolecular. While the forces that hold ions in a crystal lattice refer to ionic bonds, they do not pertain to the interaction between different molecules. Additionally, forces that repel electrons are related to electromagnetic interactions at the subatomic level, which also do not fit into the category of intermolecular forces. This understanding is essential for recognizing how different substances behave based on the interactions between their molecules.