The science behind the bang

Tag : metallic salts


The salt Tracy used in his demonstration is a solid form of copperchloride. Every element produces a flame of a different color whenburned; sodium is yellow, copper is blue and charcoal  heavy incarbon  gives off an orange hue.

Such is the basic chemistry behind coloring fireworks, Tracy said.Chemists create colors across the rainbow by combining elementsinto compounds.


Small balls of metallic salt, called stars, are embedded insidefireworks along with gunpowder. When the fuse is lit, it causes thebursting charge to ignite the gunpowder which in turn ignites thestars. Everything explodes out, and the result is a shower ofcolored sparks.

As Tracy gave his demonstration, a loud crack sounded from acrossthe room.

Toby Swaford, the education coordinator for the Fort CollinsMuseum, stood surrounded by a group of children. Everyone heldlarge, folded pieces of paper, and swung their arms downward madly.

With great effort, one or two were able to whip their arms in sucha way that caught the air, causing the paper flaps to pop out andmake the cracking noise.

You got it! exclaimed Swaford.

Though creating paper poppers isnt directly related to creatingfireworks, they do simulate the noise a firecracker makes, saidSwaford.

Its also an opportunity to talk about the history behind fireworkswhile kids make their poppers.

As a new group of children settled down to fold paper, Swafordexplained how the Chinese used firecrackers 2,000 years ago toscare off evil spirits.

He also spoke of gunpowder, which was named after the Chinese wordfor a very loud noise, gung pow.

Incorporating history with science, you never know whats going tocatch someones attention, Swaford said.