How Fireworks Explode in 5 Steps The chemistry of a fireworks show, according to legend, goes back perhaps 2,000 years. It’s a tried and true sequence of events that can be broken down into 5 steps. 1. This charge propels the aerial shell upwards once the power is ignited. 2. This ignites the bursting charges once the shell is aloft. 3. This ignites the releasing stars in the correct sequence. 4. These are the chemical explosives that burst to produce colorful streaks. 5. The cardboard shell casing rains down into a firework fallout zone, landing on the ground as charred remains.