Summertime means Fourth of July festivities. Some communities celebrate with fireworks displays. But there’s also a fiery phenomenon people can hold right in their hands—shimmering sparklers. When lit, these sticks shoot out showers of colorful embers. “There is a lot of high-energy, high-temperature chemistry going on as that sparkler burns,” says John Conkling. He’s a retired chemist and former director of the American Pyrotechnics Association, an organization for members of the fireworks industry.
To make a sparkler, a wire—usually made of the element iron (Fe)—is dipped into a wet paste and allowed to dry. The paste is made of three things: a metal fuel that provides energy, an oxidizer that allows the fuel to burn, and a glue-like binder to hold everything together. Some sparklers also contain colorants, so they glimmer with different hues. The only thing you need is a flame to set the chemical reaction in motion. Read on to find out more.