Balloon Experiment

Materials Needed:

Small-mouthed glass bottle
2 tablespoons of yeast
1 tablespoon of sugar
Balloons (only one is needed for this experiment but it is a good idea to have an extra in case the balloon is defective or it pops)
1 cup of warm water (105 F to 110 F)

What to Do:

Pour 1 cup of warm water into the bottle.
Add the yeast and the sugar.
Cover the opening and shake vigorously.
Stretch the mouth of the balloon over the mouth of the bottle, and place it where the children can observe it.
Ask them not to touch it but watch it to see what will happen. (It will take about an hour for the balloon to completely inflate.)
Explain to the children that when you mix the yeast and the sugar with warm water, it starts something that is called a chemical reaction which forms a gas called carbon dioxide.