Communities are getting ready for fireworks events this week, with colorful displays on the horizon. The Saint Louis Science Center experts shed some light on what makes these explosions glow with a variety of colors, revealing that it all boils down to chemistry.
According to scientist Will Rieger, the colors in fireworks are a result of different chemical elements reacting to energy from a fire. For example, when sodium chloride or table salt burns, it gives off an orange color. Swapping the sodium out for strontium gives a different color, like a clean, bright red. Copper chloride, which burns with a bluish green, is quite different from normal metallic copper like that found in pennies.
Other chemical compounds like potassium chlorate are also used in fireworks to produce bigger, brighter flames. Although the colors play a significant role in the fireworks displays, there are various materials packed, specifically within a fireworks shell, to create different shapes and motions during the explosion.
Materials like zinc are used to produce smoke, while aluminum creates bright sparks. By combining them and creating different effects, the way the materials explode changes. Overall, when all these chemical components come together, they create a technicolor rainbow that brightens up the nighttime sky.