WHAT YOU NEED:
Cooking oil (4 tbsp – but read the instructions on tips to estimate)
Small clear jar
Large clear jar
Water
As many colors of water-based food coloring as you have
WHAT YOU DO:
Fill the larger jar about 3/4 of the way with water
Add oil to the smaller jar. You need enough oil to cover the bottom to a depth where you can watch the food coloring fall. If you want to measure, 4 tablespoons should be close, but I’ve found it’s easier to just “eyeball” it.
Drop 2-3 drops of each color of food coloring into the oil. Make sure to spread them out, so they aren’t all in the same spot.
Notice what happens with the food coloring in the oil. You can gently stir the oil and food coloring to try to mix it up.
Slowly pour the oil into the water and watch the fireworks!
WHAT IS HAPPENING:
Water and oil do not mix because they have very different densities. In fact their molecular structures will not allow them to mix! When you drop the water-based food coloring into the oil, it clumps together instead of spreading out like it does in water. Even if you stir it or shake it, the just break into smaller beads but they still don’t fan out like they do in water.
When you pour the oil into the water, the food coloring again sinks to the bottom of the oil. But when it reaches the bottom of the oil, it has found something it can mix with! Since the food coloring is water based, when it falls out of the oil and hits the water it releases it’s color like we normally see it do in water. This creates the “firework” effect when it bursts out of the oil and releases into the water.
DISCUSSION IDEAS:
Would this work with other substances? Could you do this in milk? Soda?
