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How fireworks get their colors

The colors in fireworks help create “ohhhhs” and “ahhhhs.” But what creates the colors?

Canada Day was Friday, July 1, 2016, and Monday, July 4 is Independence Day – usually called Fourth of July – in the U.S. So it’s fireworks season in North America, and red, orange, yellow, green, blue and purple colors are exploding into our night skies. The beautiful colors in fireworks – so good at stirring our emotions – are pure chemistry, created by the use of metal salts.

Metal salts commonly used in firework displays include: strontium carbonate (red fireworks), calcium chloride (orange fireworks), sodium nitrate (yellow fireworks), barium chloride (green fireworks) and copper chloride (blue fireworks). Purple fireworks are typically produced by use of a mixture of strontium (red) and copper (blue) compounds.

The metal salts are packed into a firework as pea- to plum-sized pellets called “stars.”

Video top of post via EarthSky community member Lunar 101 – Moon Book

The colors in fireworks are created by the use of metal salts, packed into pea-sized containers called

Firework colors come from the use of metal salts, packed in pellets called “stars.”

After a firework is ignited, a lift charge propels it into the sky. That’s just explosive black powder in a confined space that, when lit, causes a fast increase of heat and gas that can send a firework as high as 1,000 feet (300 meters) into the air.

Meanwhile, a time-delay fuse burns slowly into the interior of the firework shell. After about 5 seconds, as the shell is soaring overhead, the fuse kindles a charge that reaches the core of the firework, explodes and ignites the stars that contain the metal salts.

Voila! A beautiful and colorful fireworks display.

By the way, the people who create fireworks are precise craftsmen. It’s a complex process, and even one thing being off — too much black powder, stars that aren’t aligned correctly or a trigger that fires too soon or too late — can cause everything else to go wrong.

Read more: The chemistry of fireworks

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Austin fireworks by Sergio Garcia Rill.  July 4, 2013.

Austin, Texas fireworks – July 4, 2013 – by our friend Sergio Garcia Rill.

Bottom line: The red, orange, yellow, green, blue and purple colors exploding in the night sky during a pyrotechnic festival are created by the use of metal salts.

Deanna Conners

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