An ancient art that dates to the Tang Dynasty in 7th century China, fireworks were originally believed to ward off evil spirits and bring good luck. Their popularity spread through Asia and the Middle East during the 1100s and 1200s, but fireworks did not catch on in Europe until the 17th century. By the mid-18th century, European scholars were trying to work out the secrets of China’s incredible fireworks displays.
Today, fireworks are beloved across the globe for their big bangs and dazzling shapes. Yet many fireworks fans agree that the bright, bold colors are what really make them stand out against the night sky. Did you ever wonder how they get those brilliant colors? To understand that, you will need to know a bit about the chemistry of fireworks.
What’s in a Firework?
Each firework is a carefully constructed explosive agent, kind of like a small bomb. Inside the shell are numerous small pellets that are somewhat doughy or clay-like known as pyrotechnic stars. The clay-like pellet binder holds together oxidizers, reducing agents, a fuel source, and ground-up metals or metal salts. Each of these items plays a very important role in creating the particular shape and color of the firework.
How Do Fireworks Explode?
A fireworks explosion is actually a complicated series of chemical reactions. The fuse is lit via a small explosion that causes burning rather than detonation. While the firework arcs into the sky, the wick burns away, transferring heat and gases to the pyrotechnic stars. Rapid chemical oxidation and reduction chains occur, priming the firework for a dramatic explosion. As it reaches the top of its flight path, the heat and gas buildup cause the shell to blow up with a bang, releasing the pellets in a shower of brightly colored lights.
What Are the Shapes of Fireworks?
Fireworks come in dozens of shapes depending on their chemical composition and physical construction. Peonies are the most common, and appear as a circular shower of sparks. A chrysanthemum looks a lot like a peony, but each individual star leaves a small trail, known as a tail, within the circle. A willow is a silver or gold chrysanthemum with slow-burning stars which leave long tails that resemble a weeping willow tree. In a crossette, numerous big stars travel short distances and then split into smaller stars, leaving a criss-cross pattern in the sky. Other patterns are created by mixing different types of stars. For example, a cake is a big cluster of up to 1,000 shells that are linked by a single fuse.
What Causes the Different Colors?
As the fuse burns and the heat and gas are transferred to the stars, the energy that is generated causes the electrons inside the pellets to move from their calm ground state to an excited state. After the shell explodes and the pellets begin to fall back to Earth, the excess energy is emitted as light.
Different metals and metal salts emit light at different wavelengths. This is because the gap between the excited energy state and the ground state is different for each chemical compound. Our eyes see light of specific wavelengths as certain colors, so the wavelength of the light determines the color of the firework.
White and silver fireworks typically use beryllium, aluminum, magnesium, or titanium. Red fireworks generally contain lithium carbonate, while intense reds often substitute strontium carbonate. Yellow fireworks are usually based on sodium compounds, while gold fireworks often use iron, charcoal, or lampblack. Blue is generally copper chloride, and purple is a blend of copper (blue) and strontium (bright red). Orange fireworks usually contain calcium chloride.
Of course, many modern fireworks shows use advanced techniques to create unique color compounds, hues, and shades. The exact chemical formulations are generally well-guarded proprietary trade secrets. However, no matter how much research and development a particular fireworks manufacturer does, the chemical principles remain the same. The latest and greatest next-generation fireworks show at an arena or theme park is merely the newest evolution of a process that has been in place since the 7th century AD. The fireworks that are available for purchase are also manufactured using those same techniques.
At Dynamite Fireworks, we don’t only sell top-quality, name-brand fireworks. We also provide the information you need to know to use them responsibly, legally, and safely. If you have any questions or concerns, give us a call at (219) 937-4090. We look forward to becoming your one-stop shop for all your fireworks needs!