Oil & Water Science Experiment

Experimenting with oil and water is a very basic but fun activity for young children. Our lunch bunch group loved this experiment that uses just oil, water and cotton balls.

To begin, we made predictions about whether or not a plain cotton ball would float or sink in water. (We have experimented with floating and sinking and also with oil and water in the past.)

Cotton balls are interesting to observe because they float initially. When they become saturated with water, they sink to the bottom.

Next, we used our sense of touch, sight, and smell to observe cooking oil. The students commented that it felt "slimy" and "slippery."

We dipped our cotton balls into the oil and made predictions about what would happen when we placed them into the water. Some children thought that they would float at first then sink (just like the plain cotton balls). Others thought that the oily cotton ball would sink "because it's heavy now." And one little out-of-the-box thinker predicted that the "whole thing will explode." Let's see...

The oily cotton balls floated on the top. We watched them for a while and they never sunk like the plain cotton balls.

So then we had the good idea that we should push the oily cotton ball to the bottom so it would sink. But, guess what? It floated right back up to the top!

As we were talking about what happened, one kiddo suggested that if we put the cotton balls on the bottom first, then pour the water in, that both of them would stay "sinked."

I love it when they think like this and start to make hypotheses!

We tried it, but lo and behold that oily cotton ball floated right back up to the top. It's amazing how much learning, thinking and language can take place with such a simple science experiment.

Have fun playing and learning with your children today!