Science Common Sense

175 - Why do different substances have different boiling points?

Different substances have different boiling points because of the way their tiny particles (called molecules) interact with each other.

When a substance is heated, its molecules gain energy and start moving really fast. This movement causes them to break free from the attractive forces holding them together. The boiling point is reached when the molecules have enough energy to escape into the air as gas.

The strength of these attractive forces, called 'intermolecular forces,' varies between substances. If the forces are strong, more energy is needed to break them, resulting in a higher boiling point. If the forces are weak, less energy is needed, resulting in a lower boiling point.

Think of it like holding hands with your friends. If you're holding hands tightly (strong forces), it's harder to break free and run away (boil). If you're holding hands loosely (weak forces), it's easier to break free and run away (boil).