Make your own sensory wave bottle – great for focus, concentration and to see how waves are formed. This is a perfect experiment for children to try at home in the kitchen or within schools.
You will need:
Empty plastic bottle
Blue food colouring
Vegetable or baby oil
Fill the plastic bottle half way up with oil
In a separate jug, add a small amount of blue food colouring to water to create a light blue colour. This then needs to be added to the oil. Watch what happens when the liquids meet each other – they shouldn’t box.
Slowly tip the bottle from side to side to see what happens. You should be able to make waves!
The science bit: The first reason that water and oil don’t mix is because their molecules are packed differently. The molecules of water are packed very densely. In one glass of water, there are more molecules than the number of known stars in the universe! Oil molecules are more spread out so oil is less dense and floats on top of the water. Also, oil is ‘hydrophobic’ which means it naturally repels water.