(Time required: 10 to 15 minutes)
What you need:
Tall bottle or jar or drinking glass
Water from faucet
Food such as rice, raisins or spaghetti broken into short pieces.
What to do:
1. Pour about 12 ounces/ 360ml of water into a tall bottle or jar.
2. Add 3 or 4 teaspoons of baking soda the water. Stir until all the baking soda has dissolved.
3. Add a few pieces of spaghetti (about 1-2 inches 2-5 cm long) or rice to the bottle.
4. Measure about 1 ounce/ 30 ml of vinegar with the measuring cup.
5. Pour the vinegar into the bottle and gently swirl the bottle.
6. Watch what happens to the food over the next few minutes.
When baking soda and vinegar are mixed, a gas called carbon dioxide is formed. The gas is lighter than the liquid and begins to rise to the surface, but as it tries to rise it attaches to the edges of the food. When enough bubbles attach to the food, it will rise to the surface. At the surface, the carbon dioxide escapes into the air, and the food sinks, waiting to bump into more gas. This process will often continue for 30 to 45 minutes. To keep the process going for a long while, swirl the bottle every few minutes.
Other things to try:
Try all sorts of food. Heavier pieces of food may require a much longer time before they rise. Try to figure out how to make the reaction go on for a long time.