Exploratorium

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__**Key Concepts:**__


 * Electricity travels through metals, not air, string, etc. You can easily demonstrate this... recall the simple lab you did where you inserted all sorts of materials into the circuit...
 * Electricity is "pushed" through the light bulb by power supply.
 * Electricity can be used to do mechanical work.
 * Electricity MUST travel through metals which are touching.

=__**Demos:**__=

1. Light bulbs being lit by batteries (in series)

2. Light bulbs being lit by hand-crank media type="file" key="Movie on 2012-05-29 at 14.30.mov" width="300" height="300"

3. Batteries powering hand-crank. (in series) media type="file" key="Movie on 2012-05-29 at 14.45.mov" width="300" height="300"

4. Take home mini-circuit (a coin battery in the prongs of an LED)

=__**Skit:**__=

Develop the script more to incorporate more questioning/responses from kids. You do realize that you use the term "electricity" without ever really saying what this is... is this purposeful or accidental? How will you keep the 2 batteries together?
 * Do you know anything electric that is in your own house? (microwave, lights, tv) The devices in your house are powered by electricity! The electricity that is made in power plants is sent to your house and powers almost everything in it. The electricity, however, needs a way to get from the power plant to your house. To demonstrate, I have an example of two light bulbs set up where we see three metal wires connecting the power source (battery) to the two houses (light bulbs) and back. If ANY of the wires are disconnected, the houses receive no power and the bulbs will not light. If they are all connected by metal, however, the houses will receive power and the bulbs will light. (TEST WITH NON METAL OBJECTS AND A PAPER CLIP) This metal circle is commonly called a circuit.
 * But how does the power plant generate electricity? All power plants work the same way as this hand-crank! Energy is used to turn something (crank, turbine, WINDMILL) in a motor. This generates electricity. This next demo is a hand crank which, when turned, powers the light bulbs that it is in a circuit with.
 * The next demo is meant to show you what happens when more or less electricity is sent to a device in the same circuit. When we complete this circuit between the power supply and the hand crank, we see that the hand crank spins. If we connect the hand crank to two of the batteries, we see that the crank spins even faster. If we connect the crank to all three batteries we see that the hand crank spins even faster.
 * This last demo is one that you get to keep! We are going to make our own circuit with a small battery and a small light bulb. We are going leave the circuit open, however, so that the bulb only lights when we close the circuits by pinching the battery and the metal together. This shows us how a light switch at home works. When the switch is open, the metal is not touching and the lights do not receive power. When we pinch the battery we connect the metal and the battery, creating a complete circuit, causing the bulb to light! The same thing happens when you hit a light switch to turn on the lights! We can do this by placing the battery between the metal of the light bulb, and then we tape one of the metal legs to an end of the battery, leaving the other leg separated.
 * CONCLUSION: Electricity is extremely important for us. It powers our houses, our schools, and our video games! This can only happen because of circuits very similar to the one we all made, as well as the ones I showed you earlier. It requires a circuit to send electricity from the power plant to the house, as well as throughout the house to each electronic device there.