Teachers' Domain; Physical Science/Engineering; Fireworks! Making Color

The Renaissance was a time of pyrotechnic innovation in the 200 years that followed Italian artisans developed most of the basic fireworks we know today. But one challenge remained the mastery of color. The Alchemist could create sparks and gold and silver but other colors were almost nonexistent. And then and 1830s Italian pyrotechnicians made a breakthrough. They changed the gunpowder recipe to placing potassium nitrate with Potassium Chlorate. By burning Potassium Chlorate. They were able to speed up the rate of oxygen delivered to the chemical reaction and increase the combustion temperature from 700 degrees Celsius to 2000 degrees Celsius. Now they were able to work with a whole new set of chemicals that burned at a higher temperature and produced more vivid colors. The modern display is full of color. And you might color by adding metals

not metals but metal swords to the composition. So you know if you put a piece of copper into a fire you see a glow with a blue flame and we can do the same. It's the side of a very good flower maker is the really good strong blue. And here we've added copper oxy chloride to the basic. Also the fuel mix where you get a good blue fly. Adding strontium salts to the mix makes the red flight. Ah. Adding barium to the mix. Thanks a green slice. So with those three and with other metal soaps we have a whole spectrum of colors that we can use the color spectrum is made up of wavelengths of visible light the metal salt with the longest wave length is strong it appears red when it burns. Copper

salts have shorter wavelengths and appear blue when burned by carefully mixing chemical compounds. Many color combinations can be created. And have no salts are added. All of the colors of the visible spectrum combine and the light appears bright white.