• Raisins;
• Clear, fizzy drink;
• A tall glass.

1. Pour a clear, fizzy drink (lemonade is the best example) into a tall clear glass.
2. Now drop in a raisin and wait for 20 to 30 seconds to see what happens. Why?
3. What happens after another 1 minute? Why? Try putting more raisins into the glass and see what happens!

The explanation for the dancing raisins is actually quite simple. When raisins are initially dropped into the glass they will sink, this is because raisins are denser than the liquid in the glass. However, the little bubbles you see in fizzy drinks is Carbon Dioxide, these little bubbles of carbon dioxide stick to the rough surface of the raisins and lift them to the top of the glass.

When the raisins reach the surface of the liquid the little bubbles burst and the raisins will lose the buoyancy given to it by the carbon dioxide and sink to the bottom again. This process repeats itself until all the carbon dioxide or 'fizz' in the drink has escaped.