Ah, holidays! There's nothing like them. With every occasion there is plenty of food, loved ones and just an overall good time. Though they're all special in their own right, what makes the 4th of July particularly fun are the roars, booms and flashing lights of fireworks.
When we go to our local show or witness the magnificence of Red, White & Boom all we can do is be amazed. But what is it that causes such amusement? Well, just like everything else it boils down to science.
Three forms of energy are released with fireworks: sound, bright light, and heat. The loudness of a firework is made from energy being rapidly released into the air, making the air expand faster than the speed of sound. What we get as a result is a shock wave, or sonic boom.
When metal salts are heated, such as calcium chloride or sodium nitrate, they produce various colors. Ultimately, it's all in the elements! Atoms from each element release light of specific colors. Each element has a different amount of energy, which determines the color of the firework.
There are two states: a ground state, lower-energy, and an excited state, higher-energy. Absorption of energy starts from the ground state up to the excited state. When a compound, let's say for example sodium nitrate, absorbs heat energy it gets excited. The high-energy state doesn't last long and when the sodium atom releases its energy yellow light is produced. So overall wavelengths help determine the color as well, varying from element to element.
Wow! Didn't think so much science went into the composition of a firework. Guess there's a reason why they recommend leaving it to the professionals.
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