Chemistry of Fireworks
Metal salts burn in colours and oxidisers drive the show.
About this topic
Fireworks combine fuel, an oxidiser, binders and colour-producing metal salts. Black powder (charcoal, sulfur and potassium nitrate) is used to lift shells and burst them. When heated, the oxidiser such as potassium nitrate or perchlorate supplies oxygen so the fuel can burn very rapidly in a closed shell, providing a loud bang and a spray of burning stars.
Colours come from electrons in metal atoms or ions being excited by heat and then dropping back to lower energy levels, emitting light of specific wavelengths, the same principle as flame tests and emission spectra. Strontium salts give red, calcium orange, sodium yellow, barium green, copper blue and potassium or rubidium violet. Mixtures give other shades. Blue is the hardest because copper compounds decompose at the high temperatures needed. Sparkles come from burning iron, charcoal or aluminium particles, while magnesium and aluminium give bright white light. Whistling effects come from burning rhythmically in a tube.
The craft is a precise chemistry: a shell is arranged in layers so that different effects occur at set times, and the delay fuse times the burst. Accidents happen when the mixtures are made carelessly, which is why professionals are trained, and amateurs should never make them.
A misconception is that fireworks colours come from dyes; they come from the light emitted by hot atoms. Also, perchlorates and heavy metals can pollute, so greener formulations are being developed.
Key ideas
- Sodium yellow, strontium red, copper blue
- Excited electrons emit light
- Gunpowder propels
Quick check
Use cases: where Chemistry of Fireworks helps
- Homework: review the key idea behind Chemistry of Fireworks before you start a problem set.
- Exam revision: use the quick check to test whether you can recall Chemistry of Fireworks without notes.
- Visual learning: play with the interactive lab to see how Chemistry of Fireworks changes when you adjust its inputs.
- Teaching a friend: explain Chemistry of Fireworks in your own words, then compare your version with the key ideas.
Chemistry explains medicine, food, cleaning products, fuels and building materials.
Frequently asked questions
What is Chemistry of Fireworks?
Metal salts burn in colours and oxidisers drive the show.
What will I learn in Chemistry of Fireworks?
Sodium yellow, strontium red, copper blue. Excited electrons emit light. Gunpowder propels.
Is Chemistry of Fireworks part of Chemistry?
Yes. It is one of 150 Chemistry topics on LearnViz HighSchoolEdu, with 3 key ideas, a live animation and a quick check.
Does the Chemistry of Fireworks lab work on a phone or tablet?
Yes. The animation resizes to fit your screen and supports touch, so you can drag, tap and slide with your finger.
How should I study Chemistry of Fireworks?
Read the summary and key ideas first, play with the interactive lab to see the idea in motion, then answer the quick check. If you get a question wrong, go back to the key idea it tests.
Do I need an account, and is my progress saved?
No account is needed. Marking a topic as learned is saved in your own browser, so it stays on that device and is not sent to a server.