The science behind fireworks

Who doesn’t love to watch fireworks on the Fourth of July? Have you ever watched and wondered how a firework well ... works? We can thank chemistry!

A firework is made up of small pellets (aka stars) made mostly of a black powder that contains charcoal, sulfur and potassium nitrate. The black powder has different metals or chemicals mixed in to provide color.

>> Local firework displays in the Miami Valley

The stars can be arranged in many shapes to provide a beautiful display when they are ignited.

Five ingredients are needed to create the firecrackers:

  1. Metal salts are used to produce the colors
  2. A fuel is added to start the burn
  3. An oxidizing chemical is added to provide oxygen for the combustion
  4. A chlorine-donating compound can help intensify the colors
  5. A binding chemical is added to hold the mixture together

Metal compounds when they burn provide the fireworks with their brilliant colors. Here are a few popular ones:

  • Red- Strontium
  • Orange- Calcium
  • Yellow- Sodium
  • Blue- Copper
  • Green- Barium

Weather can impact your fireworks show as well.

Obviously, thunderstorms nearby during an event are dangerous because lightning can pose a big threat.

The wind can impact the smoke and ash from the firework displays. A light breeze that blows away from a crowd is helpful, while one that blows toward a crowd is not. No wind at all could keep the smoke around and make the colors less vibrant.

Humidity can also impact how vibrant the colors appear. The more moisture in the air, the more water droplets there are to scattered the color from your eyes and that can make the colors seem less intense.