How do fireworks work? A pyrotechnics chemist explains
Here’s how fireworks are actually made
- Modern fireworks utilise an ancient black powder mixture of potassium nitrate, charcoal, and sulfur, which ignites to create a rapid combustion reaction that propels and explodes the firework.
- The burn speed and energy release of a firework are precisely controlled by adjusting the size of the black powder granules and the level of confinement.
- Vibrant colours are produced when specific chemical elements, such as strontium for red, barium for green, and copper for blue, are heated, causing their electrons to emit light at different wavelengths.
- Sparkles and flashes are generated by incorporating various metals into the pyrotechnic formula, with aluminium, magnesium, and titanium creating white sparks, and iron producing gold sparks.
- Sound effects like whistles and booms are achieved by controlling the rapid release of gas from energetic formulas within confined spaces; a small opening creates a whistle, while complete confinement results in a boom.