Liquid Sandwich Science Experiment

This is a physics experiment that focused on density.

Materials:

• 4 glasses half full of water

• 4 colours food colouring

• Salt

• 1 straw (clear)

• Measuring spoons (teaspoon)

Procedure:

• Make four different colours of water with the food colouring.

• Add 1tsp salt to the first glass, 2 tsp to the second, 3 tsp to the third and leave the fourth glass with no salt.

• Dip the straw into the first glass and seal the top of the straw with your finger. Keep it sealed.

• Dip the straw into the second glass, lift your finger up to allow some water flow, then seal it again with your finger.

• Continue to add colours to your rainbow straw. Add more layers!

• What’s happening to the coloured solutions?