Bath ‘Bombs’

Material

• 20 g sodium bicarbonate (sodium hydrogen carbonate)
• 10 g citric acid (irritant)
• sunflower oil
• 2 x 250cm³ beakers
• glass stirrer
• dropper
• cling film
• large bowl of water

Procedure

1. Put 20g sodium bicarbonate and 10g citric acid into a beaker and mix well.
2. Add the oil, one drop at a time, mixing in well. After a few drops, the mixture should begin to hold together when pressed against the side of the beaker. The mixture should still look quite dry.
3. Line the second beaker with cling film.
4. Pour the mixture into the lined beaker and pack it down tightly.
5. Twist the edges of the cling film together so that the mixture is completely enclosed, then pull it out of the beaker.
6. Shape the mixture into a firm ball and very carefully undo the cling film.
7. If possible, leave the bath bomb to dry overnight.
8. Fill a large bowl (or sink) with water and drop the ‘bath bomb’ into it. It should move about, fizzing vigorously.