Liquid Density Experiment: Color Explosion in a Jar

This super easy science experiment for kids explores the properties of liquid densities. There are so many cool liquid density experiments for kids! This one only takes just a minute to set up, and it creates a really cool effect that kids will love. This experiment was a big hit with my 6-year-old. Plus it uses materials we already have around the house, which is always a bonus.

Materials

Glass jar
Cooking oil
Water
Food coloring
Bowl
Spoon

Method

Fill the jar 3/4 of the way to the top with warm water. Set it aside.

Pour 3 tablespoons of cooking oil into a bowl.

Add about 5 drops of food coloring for each color that you’re using.

Stir the food coloring into the oil.

Note: The food coloring won’t mix, but stirring it will break the drops into smaller little dots.

Pour the oil into the jar of water.

The oil will settle at the top of the jar, but not the food coloring! The food coloring will shoot down the jar, in a color explosion!

The result is so cool. It’s such a simple and quick little experiment, and your child will probably want to go back and do it again using different colors for the next explosion.

This is something a 5 or 6 year old can easily do on their own, with minimal supervision.

The Science Behind the Experiment

This is a liquid density experiment.

It works because oil and water don’t mix – but food coloring will mix with the water and not the oil, because food coloring is water based.

Why don’t oil and water mix?

Oil and water don’t mix because their liquid densities are different. Oil is not as dense as water, which causes it to float on top of the water. Food coloring has a higher density than oil, which causes it to fall beneath the oil, mixing into the water.

This simple scientific property creates the stunning effect of a “color explosion” in the jar.