Preschool STEAM: Can You Mix Oil and Water?

The simplicity of this oil and water STEAM investigation is perfect for the three to five set.

Will Oil and Water Mix?

Objective: Learn about why water and oil don’t mix, and to see if you can get oil and water to mix.

Materials: Jar with a tight lid, food coloring,cold water, cold oil, egg yolk.

Ask: Will oil and water mix? Children won’t know that oil and water typically don’t mix. They will be shocked at how the liquids separate after just a few seconds.

Learn: Oil and water typically won’t mix. There are two reasons for this.

1. Oil is less dense than water. In a glass 1/2 filled with water and 1/2 filled with oil, there are far more water molecules, which means the water will always drop to the bottom.
2. Oil and water have different polarities. Water molecules are positive on one side and negative on the other. This causes water to stick to water. Oil is non-polar, and will only stick to non-polar molecules.

Plan: Ask your child if they think it is possible to mix oil and water. Maybe shaking the jar will mix the oil and water?

Experiment: Shake the jar to see if the water and oil will mix. It will mix temporarily, but your child will be fascinated to see that water and oil immediately start to separate.

Improve: Is there a way to get oil and water to mix? The key is to add an emulsifier that changes the molecular structure of the two molecule types. This is where the egg yolk comes into play. Drop the egg yolk into the jar and ask your child to shake the jar as hard as they can. The oil and water will mix!

STEAM Integration:

Science: Talk about how water and oil molecules are different. When the egg yolk is added, however, the oil and water are able to mix.

Technology: Take pictures of the process.

Engineering: Try different containers for oil and water. What happens if the jar lid is loose?

Art: Use food coloring to dye the water different colors.

Math: Measure the amount of oil and water in the jar. Will different amounts produce different results?