~ Empty 500ml bottle
~ Washing up liquid
~ Food colouring
1. Fill up the bottle with 1/3 of cold water.
2. Squeeze a squirt of washing up liquid into the water.
3. Add a few drops of food colouring into the water.
4. Glue the lid on to the bottle and fasten tightly.
5. Shake up the bottle and watch the bubbles appear and disappear!