The Next Five ....

6. Electric Pickle

• Safety rider on this one - make sure you work with someone who has electrical experience. Basically you design an electrical device that attaches two electrodes (two nails in a piece of plywood) to a 120 V outlet (at least in North America). This device should have a circuit breaker built into it. Many electrical power-bars have the breaker built in. Place a pickle on the two electrodes. Plug device in and watch the pickle glow. You could cook a hot dog wiener the same way, but make sure you poke a couple of holes into the wiener first. Check out a fancy version of this with fellow science education advocate Steve Spangler and his electric pickle demo.

7. Egg Osmosis using Straw and Gum

• Not your usual Osmosis demo. What makes this one work is the membrane in an egg between the shell and the inside of the egg. Gently crack one end of the egg and pick away about a dime's worth of area (or the area of your largest finger nail). When you're done, you should have the shell removed, but not the thin membrane. Then at the other end of the egg, make a hole big enough to insert about 2 cm of straw. Seal the straw in place using some chewing gum or similar material. Now place the whole thing in a glass that holds the egg upright, ensures the membrane is not touching the bottom of the glass. It's actually easier than it sounds. Then fill the glass with enough water to cover half the egg. Watch. 

8. Two Candles

• I like demo's that have different levels of learning attached to them. That way kids can say "oh I've seen that", but then you can bring a completely different line of thought into the discussion. This activity does just this thing. You need two candles - dripless are best (and I've been told IKEA has the best dripless candles). Light both candles and while holding both candles horizontally, place them in a vertical line about 10 cm apart. Quickly remove the bottom candle, blow it out and replace it back in the same position. It relights! This simple demo allows you talk about phase changes, chemical changes and convection energy transfer/currents. And for the really good observers radiation transfer as well. Plus, it provides a great opportunity for kids to ask testable questions. 

9. Reaction in a Bag

• I first came across this demo or activity sitting in an elementary school waiting to work with an amazing kindergarten teacher for the day. Not only was the day a lot of fun, this demo has been successfully completed with grade 1 to grade 12 kids. In a medium sized plastic zip-lock bag place some baking soda in one corner, and calcium chloride (rock salt) in the other. In the middle place a small amount of bromothymol blue indicator in a small container or film canister. Carefully zip up the bag without spilling the liquid. Once the bag is sealed, combine the reactants and observe. The first time you will want to place the bag on the table and step back. The carbon dioxide produced will cause the bag to expand. If it appears like the bag will pop, just release the zip lock or poke a hole in the bag. Also note the colour changes. Once you have the amounts of reactants figured out so the bag doesn't break, have the kids repeat demo. This time they can hold the bag (while wearing eye and clothing protection). They will notice exothermic and endothermic reactions depending on how they hold the bag. Very cool. A highlight of my teaching career was when a colleague told he did this activity with his grade 12 Chemistry kids and one said it was like holding a reaction in his hand. That send shivers up and down my spine.

10. Alka Seltzer Rockets

• Every time I do this activity I am impressed how quickly kids get the idea of variables and the need to control all but one when completing this demo/activity. It's a simple idea, an alka-seltzer tablet and small amount of water in a film canister. The film canister is the type where the lid fit's inside the canister. Now I'm not sure how much long we'll be able to get film, so this might be worth stocking up on now. Place the reactants in the canister, seal the canister, flip it over and place on a table or floor. 15 to 30 seconds later the canister takes flight propelled by carbon dioxide! That is pretty cool, now give the kids two tablets, some water and ask them to figure out what makes the canister go the highest. Eventually a small amount of water, and about half a tablet - crushed, does the trick. When it's done, debrief how they got their answer and you've got the teachable moment for independent, dependent and controlled variables.

11 . Flying Tea Bag

• OK, I know I said 10 demos, but this one is easy and cool, but there is a safety note. Make sure you do this demo in an area where there are no fire hazards (loose paper etc). I use a Bigelow Tea Bag, but other bags may work. When you take one of these tea bags apart and drain out the tea you'll notice the bag is a long tube. Place the tube upright on a plate and light the top with a match. Watch. The bag lifts up when it's about half burnt and light enough to be carried in the convection current that has been created by the flame. Again, just be careful to observe where the bag floats to in the room.

And finally, please remember that the safety of anyone with you and you are paramount in any of these demos. Try and practice each one before doing them in front of anyone. If you have any questions or concerns, talk to a colleague or drop me a note.

Otherwise, have fun and I'd love to hear your best demo or modification of any of the ones listed here.