DIFFUSION
Diffusion means mixing. You experience diffusion at all times. For example,
whenever you smell something, it is a result of gases diffusing. In fact, diffusion
provides evidence for the kinetic theory.
Diffusion takes place in liquids and solids as well. For example, when you add
sugar to your tea or coffee, the sugar (solid) diffuses into the liquid (tea).
However, diffusion takes place more slowly in liquids than in gases, and even
slower in solids (See Topic on Introduction to Matter).
More interestingly, however, we are alive as a result of diffusion! Gas exchange
in the lungs (via the alveoli) takes place by diffusion.
The Golden Rule: Diffusion always takes place from a level of higher particle concentration to a level of lower particle concentration. Particles diffuse until they are evenly distributed.
"What does this mean?" you might ask. Click [Continue] for further
explanations.