How do fireworks get their colour? Learn the science behind this phenomenon
Bonfire Night is a name given to a wide range yearly celebrations normally containing bonfires and fireworks. The event celebrates different traditions on different dates, depending on the country and culture. One of the most popular instances includes Guy Fawkes Night (5 November) in the United Kingdom. In this time of the year red, orange, yellow, green, blue and purple colours are exploding into our night skies. The colours in fireworks help create “ohhhhs” and “ahhhhs.” So, how do fireworks get their colour?
The simple answer is: pure chemistry. The colours in fireworks are created by the use of different kinds of metal salt.
Which salts make different colours?
Metal salts commonly used in firework displays include: strontium carbonate (red fireworks), calcium chloride (orange fireworks), sodium nitrate (yellow fireworks), barium chloride (green fireworks) and copper chloride (blue fireworks). However, Purple fireworks are typically produced by use of a mixture of strontium (red) and copper (blue) compounds.
Photo Provided by Fantastic Fireworks
How is the metal salt added?
The metal salts are packed into a firework as pea- to plum-sized pellets called “stars.”
After a firework is ignited, a explosive charge launches it into the night sky. This works by compacting explosive black powder into a small space. When lit, this causes a fast increase of heat and gas that can send a firework as high as 1,000 feet into the sky.
On the other hand, a time-delay fuse burns much more slowly into the shell of the firework. Then, after about 6 seconds, as the shell is racing over the spectators, the fuse kindles a charge that reaches the core of the firework, explodes and ignites the stars that contain the metal salts (the materiel that gives the fireworks colours).
Crafting fireworks is a very precise and detailed process performed by expert craftsmen. Clearly, it’s a complex process and if one thing is off such as too much explosive black powered, stars that aren’t positioned properly or a trigger that at the wrong time — can cause everything else to go wrong.