Static Electricity: Bending Water

This is one of the coolest demonstrations I've seen in a while... 

Rub a balloon along your hair about a dozen times. (You'll know it's enough if the hair on your arm stands up when you bring the balloon near it).

Turn on the faucet so you have a very small stream of water.

Hold the balloon near the water (but don't touch the water with the balloon).

Your hair charged the balloon with negative charges.  These attracted the positive charges in the water, causing the water to move.

The picture doesn't do it justice - you really need to try this one yourself!

You could also use a rubber comb instead of a balloon.  But, I found that the balloon worked even in really humid weather, and the comb didn't.

Electricity: Light a Lightbulb

Once your students understand the basic idea of a circuit, see if they can get a lightbulb to light.

Each student/pair/group will need a lightbulb (small ones work well), a D battery, and some wires with the ends stripped off (wires will aligator clips on the end work well if you have them).

Unless students have done this before, it will likely take them some time to figure it out. 

The trick is this...

Look closely to the filament in the lightbulb.  One end of it is attached to the bottom of the lightbulb and the other end is attached to the side of the lightbulb. 

So, in order to make a complete circuit, a wire needs to go from the battery to the side.  Then another wire needs to go from the bottom of the lightbulb back to the battery. 

It can be tough to hold everything in place, but once you get everything lined up, it works! 

After students have figured it out, usually through trial and error, I draw a giant lightbulb on the board and illustrate the circuit.

Electricity: Christmas Light Circuits

Have your students build simple circuits out of easy-to-find, inexpensive materials. 

You'll need a strand of Christmas lights* and D batteries.

To prepare the lights, cut them apart into 2 or 3 light chunks.  You'll want to invest in a cheap (or higher quality if you desire, but for this, cheap works!) wire cutter/stripper for this.  The wires are thin and could probably be cut through with a scissors, but you'll want the tool for the next step...

Strip about an inch of the insulation from each end of the lights. 

In class, hand each student (or pair of students) a strand of lights and a battery.  Have them figure out how to make the lights light.  That's pretty easy....

Then give them a second strand of lights and have them figure out how to get both strands to light.  There are two different ways to accomplish this...

1 - Twist the ends of the strands together to make one large loop.

2 - Hold the ends of each strand to the battery, so you have two loops.


Once students have found one way to light both strands, challenge them to find a second way.  After students have had the chance to experiment, talk with them about parallel and series circuits - they'll understand it, after having created them on their own!

In my experience, this leads to all kinds of extensions....
As you add strands, the lights will become dimmer.  Why?  What can you do to make them brighter again? 

The students will want to see if they can string all of their lights together and see if they can light - let them try!  How many batteries will it take?

Are smaller batteries strong enough to power the lights?

*You'll want to use clear bulbs.  One time I found a string of blue lights in the garage, which I thought would be perfect for this, seeing as I didn't want them for anything else.  But, since you're only using a D cell, the light is too hard to see through the colored bulb.  

Electricity: The Human Circuit

First, you'll need to find the "equipment". You're looking for some sort of 'toy' that has two contact points, like those shown above. The toy will 'do' someting when the circuit is completed: mine are "ice" cubes that light up in water, I've seen Easter chicks that cheep when the circuit is complete. Unfortunately, I can't tell you exactly where to find these, you just have to keep your eyes open. My best advice is to check out Walgreens/CVS/RiteAid around the holidays.

Once you have procured your supplies, the activity is very simple:

Have the class stand in a large circle. Everyone needs to hold hands. You'll be a part of the circle, one of your hands will hold a student's hand. In the other hand, you'll hold the 'toy', with one of your fingers covering one of the contact points. You'll need a student to stand on the other side of the 'toy', covering the other contact point.

If the entire class is holding hands, you'll have a complete circuit and the "ice" cubes will light up, the chick will cheep, etc. If there is a pair that isn't making contact, nothing will happen.

Expand the activity by looking for some conductors and insulators to include in your circuit!

In addition to a discussion of complete vs. incomplete circuits, it's also a chance to talk about electrolytes in your body (hence the ability for electricity to travel through bodies).