Fireworks are an important part of celebrations. They “light up” any special occasion and people look forward to seeing them on festivals. Fireworks including firecrackers, sparklers and aerial shells, work differently, depending on which type you use. The basic components of all fireworks include fuel (carbon or sugar), oxidizer (like potassium nitrate, iron oxide, potassium perchlorate etc), and a substance to control the reaction (like sulfur).
Firecrackers essentially consist of gunpowder, which contains potassium nitrate, charcoal or sugar and sulfur. This is tightly wrapped in paper and attached to a fuse. When firecracker is ignited, these components react and produce nitrogen and carbon dioxide, which builds up the pressure inside the wrapper and it burst causing the loud bang.
Sparklers comprise of metal dust from aluminum, iron, steel, zinc, or magnesium that are stuck on to a wire with other components. The metal dust is mixed into a chemical mixture containing potassium perchlorate, dextrin and water, and then molded so that it attaches to the wire. When heated the metal emits a shiny light, the color of the light depending on the metal dust and other chemicals added to the mixture.
Aerial shells are also made of gunpowder, which is packed in two pockets. When the bottom pocket is ignited, it releases nitrogen and carbon dioxide from a hole below, thus propelling the aerial shell into the sky. The second pocket of gunpowder remains attached to the aerial shell and when heated results in the colorful light that is seen in the sky. Aerial shells can be arranged during packing in a particular sequence that is visible as a pattern once they explode in the sky.
There are key elements to make sure that firework work well. The fuse is an important art of fireworks that controls the time of explosion. A fuse too long would not ignite the firework at the right height, and one too short could be dangerous, as it could result in an explosion sooner than planned. Also the chemicals added in the fireworks control the timing of fireworks, especially if it is designed to create a pattern with different lights appearing at different times.
Fireworks are dangerous to handle and only professionals who have been doing it for a long time should be allowed to experiment with it. When igniting fireworks at home, we should be extra careful and make sure children are out of harm’s way.