The importance of weak forces

The answer to this question is that most molecules, including those involved in hydrogen bonding, are attracted to each other by these weak forces, and they can have a significant effect on the physical properties of the molecule. In an effort to get students to appreciate this, we ask them to propose why, at 1.0 atmos and room temperature, non-polar Br₂ is a liquid with a boiling point of 58.8°C, while straight chain decane (C₁₀H₂₂) is a fluid that boils at 174°C.