What you need:
- Food colouring (red, yellow, green, blue)
- Milk
- A plate with slightly raised edges
- Cotton buds
What to do:
- Pour milk into the plate so the entire bottom is covered - about 6mm deep
- Put a drop of each of the food colourings into the middle of the plate on top of the milk
- Dip the end of the cotton bud into the centre of the plate, don't stir. Look what happens
- Try placing a drop of washing up liquid on the other end of the cotton bud. Place it in the plate and hold for 10 seconds and watch what happens!