Easy Three Ingredient Oil and Water Science Experiment

Science fascinates young learners. Simple experimentation is a great way for children to learn about the world around them. Using oil and water to learn about how different fluids interact is a fun and safe activity for young children.

Materials Needed for the Experiment:

- Vegetable, Canola, or any liquid cooking oil
- Cotton balls
- A clear container, such as a vase or tall glass jar
- Water

Make a Prediction

Before starting the actual experiment, gather some predictions from the students. Do they think a plain cotton ball will float in the water, or will it sink? If the children have experimented with these materials before, such as in the sinking and floating experiment, or the oil and water experiment, encourage them to use what they have already learned to make their predictions.

Observe

Begin by placing one or two plain cotton balls in the water. Cotton balls are interesting to observe because they float initially. When they become saturated with water, they sink to the bottom. Did the students predict this?

A Second Observation

Introduce the oil to the students by pouring a little into a small dish. Encourage the students to touch the oil and compare it to water using their sense of touch, sight, and smell. The students might use words like “slimy” or “slippery.”

Make Another Prediction

Ask the children for predictions about what will happen when the cotton ball is dipped into the oil and then placed in the water. Will it float, sink, or will it do something different?

Observe Again and Experiment Further

The oily cotton balls float on the top! Watch them for a while and they won’t sink like the plain cotton balls. Can the students think of a way to make them sink? Let the students experiment with different ideas, such as pushing the cotton balls down, adding the cotton balls to the container first and then pouring water over them, and other ideas they might have. Taking this knowledge that they have and using it to make new predictions and new hypotheses is a critical skill for scientific thinking.