Science Smarts: Recreate those explosive Canada Day fireworks with a little oil and water

By Patty Rooks on June 28, 2025.

I know many of us will be celebrating Canada’s 158th birthday this long weekend. It is always an exciting time to share with family and friends. The best part of the celebration in my opinion is always the fireworks show!

Just in case you cannot get out and enjoy a celebration for yourself, here is a smaller scale you can do at home, so you do not miss out. Let’s get started!

*Remember to ask an adult before doing this experiment.

Materials

– Water

– Oil (vegetable or canola)

– Several different colours of food colouring

– Tall clear glass or jar

– Spoon

– Measuring spoons

– Measuring cups

Procedure

1. Using room temperature water, fill a tall clear glass about ¾ full.

2. Place on a sturdy flat surface so the water can settle and remain still.

3. Measure and pour ¼ cup (60 mL) of oil in the glass on top of the water.

4. Observe.

5. What is happening?

6. Carefully add several drops of food colouring evenly spaced out on top of the oil. (Note: I used one drop of three different colours).

7. Using the spoon, gently swirl the oil and food colouring layer you are trying to make the food colouring break into very small droplets, not mix it up completely. Be very gentle.

8. Be patient and watch what happens now.

What is going on?

First of all, you should have observed that oil and water do not mix. The oil should have sat in a nice layer on top of the water in the glass because oil is less dense than water.

When you added the food colouring it sat in the oil for a short time and once it was broke into smaller pieces it slowly slid through the oil and into the water below exploding into a variety of colours; just like fireworks do!

The food colouring exploded into the water and not the oil because it does not dissolve in the oil, just the water because it is water soluble. Now you can enjoy your very own fireworks safely any time of the year.

Calling all educators – booking for our Hands on Learning Kits for the 2025 – 2026 school year is now open – you can book for the entire year if you have your planning ready. Email your requests ASAP as it is first come first served. As well, we are excited to offer a new Hands On Learning experience thanks to generous funding from TC Energy. We have a class set of the new Robotics Lego for grades 6-8. Book now!

Patty Rooks, senior scientific consultant Praxis Science Outreach Society. Praxis has moved! We are very fortunate to be located in the Community Futures Entre Corp Building at #202 556 Fourth St. SE, Medicine Hat, Alberta, T1A 0K8. For all your science needs, please email praxis@praxismh.ca.

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