Top Demos - Best 10 for Me .... At Least for Today!

While working with the good folks in Dufferin-Peel in Ontario Canada on supporting the grade 7 and 8 curriculum, I was reminded that a good demonstration is always a welcome treat. So, with that in mind, here's my list of tried and true demo's that always work in the class or at a party! And, most of them require minimal equipment.


Here's the first five .....

1. Egg and Broom

•  My very first demo when I taught and still probably my favourite. Place a cup of water on a table and balance a small cookie sheet on top cup. Directly in line with the cup is a spool of thread and finally an egg (fresh) on the spool. The whole structure is placed near the edge of a table so that the cookie sheet is slightly over the edge. Using a corn broom, step on the bottom and pull pack the handle. Release so that the cookie sheet is struck just before the edge of the table. Then wait for the applause.

2. Collapsing Pop Can

• Pour 20 ml of water into aluminum can. Heat on hot plate until boiling. Using tongs, safely flip can over and into a bowl of ice water. The trapped water vapour inside the can cools and the pressure drops. Atmospheric pressure then crushes the can.

3. Dancing Raisins

• My favourite materials for this demo are baking soda, vinegar, water and dried raisins (let them sit outside the bag overnight). In a colourless container or 500 ml beaker, fill a quarter full with vinegar and dilute with water until about three quarters full. Then slowly add a couple of heaping tablespoons of baking soda. Once the carbonation has the solution bubbling along nicely add the raisins. Having the kids focus on what is going on and explain it using as many science terms as they can is a great exercise.

4. Diet Coke and Menthos

• OK, I know this one is all over the Internet, but I read about it long before there was even a YouTube and got a modified version of this in a grade 9 Alberta Science textbook before this demo went big time. Using Diet Coke as it's not as sticky as regular Coke, drop a couple of menthos candies into the pop bottle and stand back. Very impressive demo of increasing surface area to increase carbon dioxide coming out of the solution. I suspect there's more going on besides this. 

5. Egg in Milk Jar

• Glass milk jars are hard to come by, but they're out there. Once you have one, you're ready to go. Peel a hard boiled egg and make sure it is slightly bigger than the hole in the milk jar. Now here's the cool part that a student teacher showed me. Place two wooden matches into one end of the egg. Light matches and place upside on top of the bottle. Have the kids focus on what happens as the matches burn out. You may have to lubricate the milk jar to ensure the egg slides easily. To get the egg out, just tip the jar up at 45 degrees and blow into the jar. Near the end of your breath, allow the egg to drop over the hole. Then let the greater pressure now in the jar push the egg back out!

Next Up ....


6. Electric Pickle
7. Osmosis with a fresh egg, straw and gum
8. 4 C's - Chemical Change, Candles and Convection
9. Reaction in a Bag
10. Alka Seltzer Rockets


What's in your demo bag?