Always have a FIRE EXTINGUISHER and ADULT HELP handy when performing fire experiments. NO EXCEPTIONS.

This video will show you how to transform the color of your flames. For a campfire, simply sprinkle the solids into your flames (make sure they are ground into a fine powder first) and you'll see a color change. DO NOT do this experiment inside your house - the fumes given off by the chemicals are not something you want in your home! One of the tricks to fire safety is to limit your fuel. The three elements you need for a flame are: oxygen, spark, and fuel.  To extinguish your flames, you'll have to either wait for the fuel to run out or smother the flames to cut off the oxygen. When you limit your fuel, you add an extra level of safety to your activities and a higher rate of success to your eyebrows. Here's what we're going to do: first, make your spectrometer: you can make the simple spectrometer or the more-advanced calibrated spectrometer. Next, get your chemicals together and build your campfire. Finally, use your spectrometer to view your flames. [am4show have='p8;p9;p11;p38;p92;p25;p52;p91;p101;' guest_error='Guest error message' user_error='User error message' ] Download Student Worksheet & Exercises

This experiment is at your own risk!  You MUST get an experienced adult to help you with this activity.

• Boric Acid or placing a copper pipe directly in the fire will give you GREEN flames
• Borax (sodium tetraborate) gives a YELLOW-GREEN flame
• Epsom salts (magnesium sulfate) will give you WHITE-PURPLE flames
• Table salt (sodium chloride) will give you YELLOW flames
• Washing soda (sodium carbonate) will give you YELLOW-GREEN flames
• Calcium Chloride (Ice Melt, Dri-Ez) will give an ORANGE flame (make sure it says 'Calcium Chloride' - there are a lot of other types of molecules used to melt ice!)
• Potassium Chloride (Nu Salt) will give you RAINBOW flames
• RED flames are made with strontium, which isn't something you want kids to be playing with.

How to Tell Which Elements are Burning

Once you've got the hang of how to make colored flames, your next step is to create a spectroscope.  When you aim your nifty little device at the flames, you'll be able to split the light into its spectra and see which elements are burning.  For example, if you were to view hydrogen burning with your spectroscope, you'd see the bottom appear in your spectrometer: Notice how one fits into the other, like a puzzle.  When you put the two together, you've got the entire spectrum. What's the difference between the two? The upper picture (absorption spectrum of hydrogen) is what astronomers see when they use their spectrometers on distant stars when looking through the earth's atmosphere (a cloud of gas particles). The lower picture (emission spectrum of hydrogen) is what you'd see if you were looking directly at the source itself. Note - Do NOT use your spectrometer to look at the sun! When astronomers look at stars, they have computers look for them - they aren't putting their eye on the end of a tube.

What about other elements?

Each element has it's own special 'signature', unique as a fingerprint, it leaves behind when it burns. This is how we can tell what's on fire in a campfire. For example, here's what you'd see for the following elements: Just get the feel for how the signature changes depending on what you're looking at.  For example, a green campfire is going to look a lot different from a regular campfire, as you're burning several elements in addition to just carbon. When you look at your campfire with your spectroscope, you're going to see all the signatures at the same time.  Imagine superimposing all four sets of spectral lines above (carbon, neon, magnesium, and nitrogen) into one single spectrum... it's going to look like a mess!  It takes a lot of hard work to untangle it and figure out which lines belong to which element.  Thankfully these days, computers are more than happy to chug away and figure most of it out for us. Here's the giant rainbow of absorption lines astronomers see when they point their instruments at the sun: Do you see all the black lines? Those are called emission lines, and since astronomers have to look through a lot of atmosphere to view the sun, there's a lot of the spectrum missing (shown by the black lines), especially corresponding to water vapor. The water absorbs certain wavelengths of light, which corresponds to the black lines. Click here for more information on Spectra of the Elements. You'll find a lot of great detail by clicking on the spectrum you want to know about. Go ahead and check out the different spectral lines with your colored campfires. Have fun! [/am4show]