Fireworks!

Earlier this month, thousands of families celebrated the Fourth of July by watching the magical fireworks display in their city. However, these marvelous bursts of light and sound are much more than a feat of magic; it takes lots of chemical reactions to create fireworks.

We think of fireworks as a modern invention, but the main ingredient of this exploding phenomenon has been around for over a thousand years! Chinese alchemists developed gunpowder in the 800s. Also known as black powder, gunpowder became the first explosive to be created, and today’s fireworks still use them. In gunpowder, potassium nitrate plays the most significant role. The potassium nitrate (the oxidizer) causes the fireworks to be sent into the air, but it also plays a large role in the bursting of the firework.

The exciting bright colors and patterns are also a product of science. Burning metal salts such as sodium chloride (table salt) creates colors. For example, burning table salt will produce a yellow flame due to the sodium metal. Other examples are copper and calcium, which produce blue and orange flames, respectively. These metal salts make “stars” which are small pellets. These stars are stored in the firework’s shell – a sphere that shoots up into the sky once it is ignited. The arrangement of the stars in the shell determines what kind of pattern it will make in the air, and that is the pattern we see when watching fireworks. Some fireworks have added chemicals, and these chemicals create different effects, like sparkles and strobing.

Pyrotechnicians have the fascinating job of measuring black powder and chemicals to create the most exceptional display. They use precise mathematical calculations to determine the correct height and location that the fireworks explode. Next time you see the dazzling fireworks light up the night sky, you will be able to tell everyone all about how they work.

Source:

“How Do Fireworks Work?” The Library of Congress,
https://www.loc.gov/everyday-mysteries/chemistry/item/how-do-fireworks-work/ opens in a new window

The Science of Fireworks, 2016,
https://www.ontariosciencecentre.ca/science-at-home/diy-science-fun/the-science-of-fireworks opens in a new window

Scientific Peer Review by Alysia Mandato

Aneri Shethji:

Aneri Shethji is a 10th grader at North Allegheny Intermediate High School. She is very passionate about science and writing and enjoys getting involved with the community. In her free time, Aneri spends time with friends and family and loves getting outside. She can’t wait to learn more about all that science has to offer, and help others learn it too!