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Robert Krampf's Experiment of the Week |
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This Week's Experiment - #189 What is Smoke? |
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Well, I hope you have all had a fun week of sticking your tongues out. I |
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have been having a blast doing fire shows at the Hastings Museum, in |
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Hastings, Nebraska. The crowds are great and the staff is even better. |
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Well, did you figure out how a set of muscles that can only pull will let you |
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stick out your tongue? The muscle responsible for sticking out your tongue |
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is called the genioglossus. One end is attached to your lower jaw, just |
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under your chin. The other end is attached to the back of your tongue. When |
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the genioglossus muscle pulls, it pulls the back of your tongue forward and |
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this makes your tongue stick out. |
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I have been doing fire shows all week, so I thought we would do a fire |
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related experiment. As with all experiments that use fire, BE CAREFUL AND |
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SAFE. Follow proper safety procedures and think about things before you try |
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them. You should also have another adult with you, just in case you have an |
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accident. |
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For our experiment, we are going to take a look at smoke. What is smoke made |
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of? To find out, you will need: |
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a candle |
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a candle holder |
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a metal fork |
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a paper towel |
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Place the candle in the candle holder. If you don't have a candle holder, |
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you can make one by crumpling a sheet of aluminum foil around the base of the |
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candle and pressing it against a flat surface. Be sure that it holds the |
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candle very well, so it does not fall over. Place the candle and holder on a |
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flat surface and light it. Take a minute to watch the flame. If you look at |
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the base of the flame, you will see that part of it is blue, while the rest |
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of the flame is yellow. You will also notice that the center of the flame is |
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darker than the outer part. |
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Be sure that you are using a metal fork. A plastic one will not work. Don't |
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worry. We are not going to damage the fork. Hold it by the handle, with the |
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tines (that is what you call the pointy parts of the fork) held flat. Place |
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the tines in the flame, just below the top. Slowly move them downwards. You |
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should notice some black smoke coming from the flame around the fork. Remove |
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the fork and the smoke will stop. |
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Be careful, as the fork is still hot. Wait a couple of minutes for it to |
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cool and then rub the tines across a paper towel. What do you see? Black |
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stuff. Oh no! Did we burn the fork? No. Rub the fork with the paper towel |
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and all of the black stuff comes off. The fork is not hurt. |
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Where did the smoke and the black stuff come from? They came out of the |
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flame. When you light the candle, some of the wax melts. This melted wax |
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soaks up the wick, just as water soaks up into a paper towel. As the melted |
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wax gets closer to the flame, it gets hotter and hotter. When it gets hot |
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enough, the wax comes apart, forming several new chemicals. One of them is |
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the chemical carbon. Carbon is the black stuff that is left behind when you |
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burn a piece of paper, a piece of wood or a piece of toast. It is also the |
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black stuff that you wiped off of the fork. |
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As long as the flame is not disturbed, the carbon burns up inside the flame. |
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This carbon is also what gives the flame its yellow color. The blue bit of |
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flame at the bottom is low enough that the carbon rises above it, so it does |
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not get the yellow color. Without the carbon, the entire flame would be blue. |
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When you put the fork into the flame, it causes a disturbance in the flame. |
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This allows some of the carbon to escape before it burns up. These tiny bits |
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of carbon rise from the flame to form the smoke that you see. |
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Not all smoke is made up of bits of carbon. Blow out your candle. Notice |
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the smoke that is rising from it. This smoke is white, not black like what |
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we saw earlier. This smoke is made of tiny bits of wax that have not come |
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apart yet, so there is no visible carbon. That is why the smoke is white |
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instead of black. |
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For you to be able to see smoke, it has to contain tiny bits of something. |
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Different kinds of smoke are made of different things, depending on what you |
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are burning. Often, it contains chemicals that are harmful. If you breath |
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it, those tiny bits wind up in your lungs, which is not a good thing. In |
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general, it is not a good idea to breath any kind of smoke. Take a look at |
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the paper towel that you rubbed with the fork. Would you want that stuff in |
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your lungs? Not me. If I want some carbon inside me, I will go burn a piece |
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of toast for a snack. Or maybe toast a marshmallow until the outside is |
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black and crispy (carbon). And of course, you can't toast marshmallows |
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without some chocolate and graham crackers...........Well, gotta go fix a |
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snack. Bye for now. |
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Get volume 1 of the Experiment of the Week postings in book form! To order, |
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send $9.95, plus $3.00 postage and handling to: |
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Robert Krampf |
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PO Box 60982 |
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Jacksonville, FL 32236-0982 |
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Include your e-mail address and I will notify you when I get your order. |
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If you would like to be on the list, just send me an e-mail at [email protected], asking to be added to the Experiment of the Week List. |
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Check out our web site at: |
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http://www.krampf.com |
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From Robert Krampf's Science Education Company |
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4850 A1A South |
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St. Augustine, FL 32084 |
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(904) 471-4578 |
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