"Sure, I'll Blow Something Up For You!"
But I am a teacher. I'm supposed to be a positive role model for my science students. I can't just go around "blowing things up"! There are those who would say I should never "blow anything up" in front of students or engage them with science demonstrations of any kind. They suggest that students become zombies waiting to be entertained with little or no learning taking place. I would even tend to agree with this if demonstrations were the only thing we ever did.
An awesome science demonstration will emotionally engage your students for a moment ... but a moment is all you need to provide them with an unforgettable learning experience. Even more important than the concepts learned are the attitudes developed for the love of science. But why stop there? A demonstration a day, or a week, will soon create students who can't wait to get to your class to see what is next. Then when you provide hands-on lab experiences your students will be first in line to participate. If your students love coming to your class to experience the fun of science ... they will learn! After 33 years of teaching middle school science I am completely and utterly certain of this!!
Demonstrations come in all shapes and sizes. You may be demonstrating Newton's Laws of Motion with a wire coat hanger and a coin, showing the phases of the moon with models and a flood light, or showing the explosive nature of sodium metal when it comes in contact with water. Some demos are safe and easy to perform while others require considerable caution and experience. All demonstrations should engage your students emotionally and intellectually and should leave them with questions that they want answers to. Above all else, all demonstrations should be performed with absolute safety to the demonstrator and the audience.
This sort of brings us back to the "blowing up" thing. A demonstration can make a loud bang, create a fireball, send pieces of eggshell flying harmlessly toward a safety shield, but a demonstration should NEVER EVER recreate a bomb. Students need to be reminded constantly how your demonstration is NOT a bomb and that they should never attempt to make a bomb. When they read such things in the dark side of the internet they will have seen the power of chemistry and will have been exposed to a set of values as to why they should never attempt to make a bomb.
We're teachers. We're told to teach our students what's on the syllabus and send them on their way. But as teachers, we have an awesome opportunity to not only teach them what's on the syllabus, but to instill values within them that they can carry throughout their lives. That being said, loud bangs are cool. They're attention-grabbing. So USE THAT MOMENT. When they're captivated. When you've just become a cooler teacher than you were a minute ago.
So when I speak of "blowing things up," I mean blowing things up responsibly. Never recreate a bomb or show your students how to. Your biggest and loudest bangs should release energy harmlessly without confinement. Your potentially dangerous demonstrations should involve chemicals and materials that students would find difficult to obtain. Always preach safety and demonstrate safety to instill those values in your students.
Before I scare you away, try this little demo with your students:
POTATO CANDLE (don't tell your students the title ... let them think it's a real candle)
Use a cork boring tool to core out a cylindrical section of a raw potato.
Make a small slice at the top and place an almond sliver at the top (so it looks like the wick).
Light the almond sliver (it will burn), dim the lights, and ask your students to silently make observations of a burning "candle".
Carefully blow the candle out, wait a few seconds for it to cool, and take a big bite out of the top of the candle. Play it up if you like and tell them its the best candle you've ever eaten.
Sometimes things aren't always as they seem. Let them think about this but don't give them an explanation.
Click here for more details on the Potato Candle
If you like this demonstration check out the DEMONSTRATIONS section of gonyoscience.com. We are adding new demonstrations, categorizing them by skill level (Basic / Intermediate / Advanced) and adding detailed descriptions for you to try them safely with your students. Please be patient, we are just getting started to develop this section of our site.
Jim Gonyo is a retired middle school science teacher and who just can't seem to let go. To that end he has created www.gonyoscience.com where his new journey is just beginning.