Fireworks: A chemical explosion in the night sky

July 4^th is a date that I mark in my calendar with great anticipation. Each town in the Adirondacks comes to life with family activities, fireworks displays, town parades and live music. Sometimes the celebrations are only for a day while others extend to a weeklong celebration.
Fireworks have always intrigued me as a child. Even today fireworks have a feeling that arise from nostalgia mixed with a sense of wonder. The history of fireworks begun in China around 960-1279 during the Sung dynasty. It is said that a cook in ancient China found that a mixture of sulphur, saltpeter and charcoal would explode in an enclosed small space.

Around the 19^th Century, a mixture of metallic salts and potassium chlorate were introduced to give an aesthetically pleasing characteristic. The creation of a color scheme required the application of art and physical science. The light points ejected from fireworks, known as stars, requires an oxygen-producer, fuel, color producer and a binder to keep everything in an enclosed space.

There are two main mechanisms of color production in fireworks, incandescence and luminescence. The first is incandescence. Incandescence is a light produced from heat that causes a substance to become hot and emit an infrared light starting with red, then orange, yellow and white as it becomes increasingly hotter. When the temperature of a firework is controlled, the glow of the components, such as charcoal, can be manipulated to the desired color at the right time. The second is luminescence. Luminescence is another light produced using energy sources other than heat. Sometimes this light energy is called “cold light” because it can occur at room temperature and cooler temperatures.

The firework colorants vary from white to red. Some of the colorants in fireworks include:

· strontium carbonate burns red

· copper makes blue

· mixture of strontium and copper compounds makes purple

· barium chloride glows green

· charcoal and lampblack makes gold

· sodium nitrate produces yellow

· magnesium, aluminum, and titanium give off white sparkles or a flash

Fireworks come in all forms; from sparklers used in our backyard to shooting rockets into the night sky. In this time of the year please take extra precaution in the use of fireworks to deter any injuries; especially to young children.

Lastly, be sure to check out the many activities happening in your next of the woods and may you all have a wonderful 4^th of July.