by Alan Zisman (c) 2003
Electricity works when tiny particles called electrons (which are part of an atom) move in a circuit-- a complete path from an electrical source like a battery through a load -- the part like a light bulb or a buzzer or a fan.
Electricity move easily through conductors. Insulators don’t let electricity move through it easily. Metals are good conductors.
We’re going to use a computer program, the Virtual Electricity Lab to make a circuit, and test various materials to see if they are conductors or insulators. Open the Virtual Electricity Lab... you’ll see something like this:
You drag the parts you want from the left side to the green area at the right... connect them with wires (when the little green hand is selected). To remove a part, click on the wirecutter icon, then click on the part that you want to get rid of.
A. Make a simple circuit.
You will need
the following parts:
Click on the little switch icon (in the left-hand part of the screen), then you can flip the switch on... make sure the light bulb lights up. If the light bulb lights up, you made a complete circuit. Turn the switch off.
1. What happens to the light bulb when you turn the switch off?
2. Why? (Hint: do you have a complete circuit anymore? Can the electrons get back to the battery?)
With the switch off: Remove the wire on the right-hand side. Click on the Other items on the left side, and scroll down to find the wax crayon. Add a crayon to the circuit, adding wire to connect everything together. Turn the switch on.
3a. Does the lightbulb light up? _____
b. Is wax a conductor or insulator? _______________
Replace the crayon with a rubber eraser, and test your circuit.
4. Is rubber a conductor or insulator? _________________
Replace the eraser with a piece of paper and test your circuit
5. Is paper a conductor or insulator? ___________________
Replace the paper with a block of wood and test your circuit
6. Is wood a conductor or insulator? ___________________
Replace the wood with the plastic spoon and test your circuit
7. Is plastic a conductor or insulator? ___________________
Replace the spoon with the scissors and test your circuit
8. Is the scissors a conductor or insulator? ___________________
Replace the scissors with the paperclip and test your circuit
9. Is the paperclip a conductor or insulator? __________________
10. Fill in the table below, first predicting whether you think the items will be conductors or insulators, then testing to see if your predictions are correct:
11. Most of the conductors have something in common. What do you think it is?
Be able to define the following electricity vocabulary words (they may be on your test for this unit):
a) electron ______________________________________________________