Question

In terms of collision theory, why do fridges keep food fresher for longer?

Answer 1

Less energy to provide to molecules, fewer molecules reach activation energy.

Explanation:

Food cam go off due to different chemicals reacting with, or colliding with other molecules, in the food. Molecules have to collide with a minimum amount of energy, the activation energy or `E_a`. The lower the temperature, the less energy the molecules have, and the slower they therefore go. A fridge provides quite low temperatures, meaning fewer molecules have `E_a` or higher. As there are fewer molecules to create a reaction, the food is kept fresher.