The Science of Firework Colours

“Remember, remember, the fifth of November, The Gunpowder Treason and plot”


On this last day of ThatBiologist does Halloween we’re going to explore the science of fireworks! A long time a go I did a 6 facts in 60 seconds post on fireworks here. However today we’re going into more detail on firework colours!

Explosions have been around for a very long time and fireworks have often been used as a sign of celebration. Chinese people are believed to have made explosive rockets in the 6th century CE during the Sung dynasty (960–1279CE). The word “firework” comes from the Greek word pyrotechnics, which means “fire art” or “fire skill”. Fireworks are in essence a controlled explosion inside a missile.

The beautiful colours and styles of fireworks come from a chemical reaction. How it works is that there will be a particular metal compound and an explosion. The metal reacts with the explosion to produce a colour. Sodium compounds give yellow and orange, for example, copper and barium salts give green or blue, and calcium or strontium make red.

Here’s a very cool infographic from Compound Chem explaining that in a bit more detail:

Image result for firework chemical reaction

Make sure you stay safe this guy fawkes night as fireworks are very dangerous. This brings this years ThatBiologist Does Halloween to a close. I hope you’ve enjoyed this week of posts. Feel free to let me know your favourites with a quick tweet or in the comments below!

ThatBiologist Everywhere!





Why aren’t all plants green?

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As part of my time off I took yet another visit to kew gardens with a friend who had never been before. Every time I go I learn a little something different and this time I was wondering about colours of plants. Most plants are green in colour but not all! Today I thought we would explore why this is?

Why are plants green?

Plants are green because their cells contain chloroplasts which have the pigment chlorophyll. This pigment absorbs deep-blue and red light, so that the rest of the sunlight spectrum is being reflected, causing the plant to look green.

What other plant colours can you get?

Think of a colour any colour, you can almost definitely find a plant that colour! Often the colours are found in the flowers but some plants have different coloured leaves too!

Why do plants have different colours?

Often the colours are an adaptation to attract different pollinators. The colours come from different chemicals that absorb different wavelengths of light leaving different colours behind!

Hope you feel like you’ve learnt something a little different this Wednesday! See you on Sunday!

ThatBiologist Everywhere!