Fireworks in a jar

We thought we would introduce a bit of kitchen science in our "try it at home" series. I'm sure your little scientist is already getting excited about Bonfire Night, so this week's activity ties in with that and we will be showing you how to make FIREWORKS IN A JAR.

For this you will need:

  • A clean jar (the larger the better)
  • A bowl
  • Warm water
  • Vegetable oil
  • Food colouring (3-4 different colours)
  • A fork
jar fireworks.jpg
  1. Fill your jar three-quarters of the way full with warm water.
  2. In a separate bowl, mix 3-4 tablespoons of vegetable oil with four drops each of the different food colourings.
  3. Use the fork to gently mix the oil and food colouring together.
  4. Gently pour the oil mixture into the jar.
  5. Watch what happens - the food colouring will slowly sink out of the oil and into the water. When this happens, it will expand and mix with the other colours, creating "fireworks".

The science part

Food colouring dissolves in water, but not in oil. The oil is less dense than the water, so it will float to the top when poured into the jar. The droplets of food colouring will start to sink, because they are heavier than the oil. Once the droplet of food colouring sink into the water, they begin to dissolve - which looks like a tiny explosion!