Science always sparks great interest and questions from children when involved in experiments. Encourage your child to learn about density of liquids by having prepared this mixing oil and water science experiment. It’s great fun and you can prepare it with only a few simple ingredients.
Possum (aged 8 years) and Boo (aged 5 years) absolutely love to engage with science experiments and this was certainly a fun one for us to try at home.
This simple science activity teaches children about liquid density and highlights how some liquids are heavier or lighter than others. It’s visually appealing and makes for some great opportunities for younger ones to verbalise what they see is happening.
Recommended age – 5 years +
(Strict and active supervision is required at all times)
Mixing oil and water science experiment
For this science activity, you’ll need to collect the following items –
- Baby oil
- Bowl or jar
- Small cups
- Food coloring
Items required for this experiment are found around the home or at your local craft store.
Begin by filling some small cups with water.
Add 2-3 drops of food coloring to each cup and stir with spoon.
Fill the larger cup or bowl with baby oil.
Keep in mind, you don’t need to fill your bowl too much with oil. About 1/4 or 1/2 way is fine.
Fill a dropper with the colored water and have your child sprinkle the water over the oil and observe.
Can your child describe what is happening?
Your child should be able to observe that the droplets of water do not mix with the water.
Why does the oil and water not mix together?
There are two parts to this answer.
Firstly, the molecules in oil are attracted to other molecules in oil.
Same with water, water is attracted to water!
Secondly, oil and water have difference densities. That means they weight different amounts. Oil is much heavier than water so the oil is likely to sit towards the surface of the water. This mixing oil and water science experiment for kids is fascinating!
Additional information about the science of this activity can be found at this great article.
Your child should notice, adding more and more droplets makes no difference. The water and oil will still not combine. The oil and water would continue to separate, regardless if it were to be shaken in a tightly sealed jar.
Oil and water are not friends!
Over time teeny tiny droplets of water will look to discolour the oil, but will soon separate again.
Mixing oil and water science experiment (extention)
You might like to extend this activity and challenge your children by adding a few drops of liquid dishwashing detergent.
Does the liquid detergent change your original observations?