Rebecca Lai's fascination with fireworks started around the age of 5 when she watched Chinese New Year celebrations in Hong Kong. She has incorporated some of the history and science behind fireworks into the undegraduate course she created, "A Muggle's Guide to Harry Potter's Chemistry" (CHEM 192H).
The Science
The colors in fireworks are created by pyrotechnic bursts containing five ingredients:
Color-producing compounds: Specific compounds produce intense colors when burned. Generally, these compounds are metal salts. Watch the animated gif above to review compounds that generate specific colors.
Fuel: Allows the fireworks to burn. Gunpowder, a mix of potassium nitrate, sulfur and charcoal, is most often used.
Oxidizer: Compound that provides oxygen to fuel combustion. Most likely nitrates, chlorates or perchlorates.
Binder: Holds the chemical mixture together. The most common binder is a mix of dextrin (starch) and water.
Chlorine donor: Help strengthen some colors. In some firework mixtures, the oxidizer can act as a chlorine donor.
Adapted from "Science fuels Lai's fascination with fireworks" in Nebraska Today. Read a brief history of fireworks and Lai's research with electrochemical biosensors and development of the Harry Potter-themed course at the link.
