The Science of Fireworks: Explosive Chemical Reactions in the Sky

Fireworks work through rapid combustion reactions that release heat, light, and gas.
The bright colors come from metal salts—like strontium for red or copper for blue.
Gunpowder, a mix of charcoal, sulfur, and potassium nitrate, is the classic propellant.
The explosion creates hot gases that push fireworks high into the sky.
Different chemicals emit different wavelengths of light, producing dazzling hues.
The arrangement of “stars” inside the shell determines the firework’s shape.
Chlorates and perchlorates act as oxidizers, fueling the intense reactions.
Sound effects—booms, crackles, whistles—come from gas expansion and burning metal powders.
Pyrotechnicians design timing fuses so colors and effects burst at just the right moment.
Fireworks are pure chemistry in action, combining art and science to light up the night.