You will need:
- a balloon
- 2 tsp bicarbonate of soda
- 150ml vinegar
- a funnel
- an empty soft drink bottle
- Using the funnel, put the vinegar into the bottle.
- Again with the funnel, tip the bicarb soda into the balloon
- Put the balloon on the bottle and shake gently to make sure all of the bicarb of soda falls into the vinegar… also make sure the balloon is on properly or you will get messy!
- (Hold on to the bottom of the bottle)
Watch what happens!
We also found this video from Questacon which shows how it is done: