This question is about propane (C₃H₈).
Figure 7 shows the displayed structural formula of propane.
Explain why propane has a low boiling point.

Propane (C₃H₈) is a simple molecular substance. 1. **Structure:** It consists of individual C₃H₈ molecules. The covalent bonds within each molecule (C-C and C-H bonds) are very strong. 2. **Intermolecular Forces:** However, the forces of attraction *between* the propane molecules are weak intermolecular forces (van der Waals forces). 3. **Boiling:** When propane boils, it is these weak intermolecular forces that are overcome, not the strong covalent bonds. Because the forces are weak, only a small amount of thermal energy is required to separate the molecules and turn the liquid into a gas. This results in a low boiling point (-42 °C).