…also, Science in Suburbia is not responsible if you start burning things after reading this post.
I don’t always watch television, but when I do, it’s usually a game show, a cooking show, Mythbusters, or anything with Neil Patrick Harris in it. So imagine my elation when I learned that Neil Patrick Harris and his better half, David Burtka, were judges on the latest Iron Chef. I’ve been known to enjoy a cocktail or two in my time (though that consumption has dropped precipitously as I’ve reached my later twenties), so I was only further excited to see that the secret ingredient was scotch.
Because cooking with alcohol pretty much demands hot flambe action, several pans lit up with lovely red-orange flames. It gave me flashbacks to one of the lab activities in my very first real science class way back in seventh grade. We did the classic flame test: burning different substances to see what color flames they produced. At the time I think we glossed over the physics of the phenomenon, instead using the activity to practice lab safety and learn how to write a lab report.
But we will discuss the physics here. Remember when we talked about the photoelectric effect? Different colors of light have different frequencies, and the higher the frequency of the wave, the more energy it carries. Electrons also carry different energies. The energy of an electron depends on its location in the atom; the electron loses energy when it transitions from a higher-energy location to a lower-energy location, and that lost energy is released as a light particle (photon). Transitions within different atoms, and even transitions between different locations in the same atom, result in different changes in energy. Different energy changes = photons of different energies = light waves of different frequencies = flames of different colors.
Fireworks displays take advantage of this phenomenon, and I’m pretty sure colored-flame birthday candles do as well. Want to get a kid interested in science? Take her to a fireworks display or stick a colored-flame candle in a cupcake. I can guarantee you she will ask where the colors come from. Come to think about it, an adult would probably ask the same question. Getting adults interested in science is fun too!
Adults who are already interested in science may now decide to see what color flames various household substances emit. SiS applauds your scientific curiosity but recommends that you stay safe.