A great Halloween science activity that’s also brilliant for bonfire night. Pine cones that give bright colourful flames can be bought online but it’s much more fun and more interesting to make them yourselves. These pine cones give flickering green flames which are an amazing sight at any time.

This science activity involves fire and a somewhat dangerous chemical, so this is for the grown ups to do and the kids to watch from a safe distance. 

You will need

Some pine cones

Some copper sulphate, about 20g for every 100ml of water

A bucket

Some hot water

A wood stove, bonfire or chimnea

You will do

Place the pine cones in the bucket and add just enough hot water to cover them.

Read and follow the safety advice on the copper sulphate! Pour some of it into the bucket and stir until the copper sulphate is dissolved.

Leave the bucket for about 24 hours for the mixture to soak in to the pine cones. Make sure it is left somewhere children or pets won’t get to it.

Take the pine cones out and leave them somewhere to dry for another 24 hours or so. Once dry you can store them until your bonfire is ready. When your bonfire is nice and hot just place the pine cones in it and enjoy the green flames. We’ve found that it’s better to wait until the flames from the fire have died down a little or the yellow flame from the wood burning will mask the green from the pine cones. It will enhance the effect if you sprinkle a little more copper sulphate over the cones just f they go in the fire.

What’s the science?

You might remember from school that different metal ions glow with different colours when you heated them in a Bunsen burner. This is all because of electrons. Everything is made of atoms and atoms are made of little bundles of protons and neutrons surrounded by electrons whizzing around like planets around the Sun.

These electrons can absorb energy, from the heat of the fire. But they can’t hold on to the energy for very long and must quickly release it as light. But the electrons are quite specific about how much energy they can absorb so they release a specific quantity of energy. Yes folks, this is quantum physics going on in your fire. Different quantities of energy correspond to different colours of light. Copper ions absorb and release a quantity of energy that makes green/blue light. Isn’t quantum physics beautiful science fans?

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You’ll love it because it’s so easy. It just arrives at your house with everything you need to do all the experiments. Unlike other science kits there’s no looking in the back of cupboard for cream of tartar or figuring out where you can buy propanol on a Sunday afternoon.  You just open the box and get started with ease.

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Would you like to see some more fun Halloween science experiments?