Diffusion is the movement of atoms, ions, or molecules from an area of higher concentration to one of lower concentration. The transport of matter continues until equilibrium is reached and there is a uniform concentration through the material.
Examples of Diffusion
- Distribution of perfume where it is sprayed in one part of a room, yet soon you can smell it everywhere.
- Movement of a drop of food coloring in a glass of water, where eventually the entire glass will be colored.
- Making tea, where molecules from the tea cross the tea bag and spread out into the cup of water.
- Shaking salt into water. The salt dissolves and the ions move until they are evenly distributed.
- Lighting a cigarette, where the smoke spreads to all parts of a room.
- Placing a drop of food coloring onto a square of gelatin, so that eventually the color will spread to a lighter color throughout the block.
- Carbon dioxide bubbles diffuse from an open soda, leaving it flat.
- If you place a wilted celery stick in water, water will diffuse into the plant, making it firm again.
- Water diffuses into cooking noodles, making them bigger and softer.
- A helium balloon deflates a little bit every day as helium diffuses through the balloon.
- If you place a sugar cube in water, the sugar will dissolve and evenly sweeten the water without having to stir it.