For kids, July 4 is all about the fireworks, and this year’s displays may be more limited than in years past due to COVID-19. With a glass jar, food coloring, and vegetable oil, this easy science project mimics colorful fireworks explosions at home in your kitchen!
 
In this Kaleideum At Home video, Caitlyn takes us through the steps to make fireworks in a jar and explains the science behind why real fireworks have color!

 

Items you’ll need

  • Wide mouth jar
  • Warm tap water
  • Food coloring (water-based)
  • Oil (vegetable or canola)
  • Fork
  • Bowl

Let’s Begin!

  1. Pour 2-3 tablespoons of oil into a bowl.
  2. Add drops of food coloring to the oil.
  3. Mix up the food coloring in the oil so the large drops become small drops.
  4. Fill the wide mouth jar with water ¾ of the way full.
  5. Pour oil into the wide mouth jar with the water.
  6. Watch as the fireworks begin!

The Science

Oil is lighter (less dense) than water so it will not mix with water and floats on top. Most food coloring is water-based, so it will not mix with the oil. Instead, the food coloring is heavier than the oil and will start to fall like rain, thanks to gravity. Once the food coloring reaches the water, it will start to dissolve or mix with the water in the glass creating a beautiful show that looks like fireworks.

Have you ever wondered why fireworks are different color?

Fireworks are mainly made up of powdered charcoal and potassium nitrate. The powdered charcoal reacts with the potassium nitrates oxygen and acts as the fuel for the firework to launch into the sky, after it has been ignited by a flame. There is a little sphere inside of a firework that also might have a few other chemicals that react with the heat. The molecules in the different chemicals get excited and release energy as a photon, or light. This is what we call luminescence. Here is a list of the different chemicals that are sometimes in a firework to make it different colors:

  • Blue – Copper
  • Red – Strontium
  • Yellow – Sodium
  • Green – Barium
  • Orange – Calcium

Let us know how your fireworks in a jar turns out and share pictures of it with us on social media! Have a safe and fun Fourth of July!