Chemistry / Unit 7 Chem 1291 short lesson, about 20 seconds
Diffusion
Captions available
The idea
Diffusion is the spread of gas molecules from a region of higher concentration to a region of lower concentration through random motion.
In practice
An opened perfume bottle's scent gradually spreads through a still room as its molecules diffuse from where they are concentrated.
Where people slip
No molecule moves toward "low concentration" on purpose — the net drift toward it emerges from millions of random directions.
Your place on the trail
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