Fireworks are the grand finale of many special events. They mark a celebration in a breath-taking way. Everyone loves the show the fireworks put on. The sights, sounds, and smells of a firework show are hard to miss, it's a spectacle. The perfect timing of the sparks leaves people awestruck. People of all ages love fireworks! Have you ever wondered how we make these grand displays so vibrant and unique? Read on and find out!
Fireworks need fuel, an ignition source, and oxygen to keep the reaction going. The fuel in fireworks usually includes some combination of carbon, potassium chlorate, or sulfur. Sulfur and carbon are good fuel because they burn quickly. Potassium chlorate, when heated, provides lots of oxygen for sulfur and carbon to burn.
The explosive powder gets confined in a small space and ignited. This reaction releases gas and heat, which allows the firework to shoot up to 1000 feet in the air. The explosive fuel produces a bright and hot fire, giving out a magical look and feel. This is the chemistry behind our favorite sparks in the air.
We know about the explosion, but what about the colors? The ingredient that results in different fireworks shades is a type of salt mix. When we add different types of salt to the mix, they give off different colors:
Sodium Salts, aka table salt, gives off sharp yellow colors.
Strontium salts produce red colors.
Copper salt solutions give us blue colors.
Calcium salt has an orange color.
Even more colors are possible by combining two different salts.
Mix Red Strontium salts and Blue Copper Salt and you get shades of purple
Adding White Hot Magnesium and Aluminum gives us a silver spark
Titanium with our silver mix can give us a white explosion.
Add a chlorine mix to a firework to help increase the color intensity!
Veteran firework viewers among us may have seen a variety of firework shapes. Hearts, ties, bows, stars. Shapes are the result of salt packet placement in the firework, in compartments called "pyrotechnic stars" or "bottle stars". Place the pea to plum sized containers in whatever shape you can imagine. The tightly packed mixture container is your canvas. The firework will translate to that shape when exploding!
There is a unique way to time these explosions to give the right shape and colors. In combination with others fired at the right angle, you can create some pretty impressive images in the night sky!
It's best to leave these things to professionals and enjoy the show! Explosions and mixture measurements can be very dangerous for amateur enthusiasts. Pyrotechnics need to be made under the strict supervision of trained professionals!