Charge! for Scientists
This show can be adapted for grades 2-8.

Materials

This equipment is located in the Lederman Science Center. Please talk to Susan Dahl.

Balloons
PVC pipe and wool
Electroscope (glass jar with wire hanging from top and two small pieces of aluminum foil hanging from wire)
Van de Graaff generator
Bar magnets with opposite ends painted blue and red
Circular magnets and pencils
Compass
Iron filings
Battery, wire and nail
Things kids can do at home
Olga's overheads
David Christian's PowerPoint

Demos

Balloons - Ask for a few volunteers and have them rub a balloon on their head or shirt.

PVC pipe and wool - Pour a bunch of pieces of various material onto the table in the front of the room, including pieces of aluminum foil, styrofoam peanuts, paper clips, staples. Have a student rub the wool on the PVC pipe, and then try to pick up some things in the pile of stuff. If they build up enough static electricity, some of the aluminum foil and styrofoam peanuts will be attracted to the pipe. They may even look like they're "dancing".

Electroscope - There is an electroscope (a glass jar with a wire hanging from its top and two small pieces of aluminum foil hanging from the wire) in the equipment. Rub a balloon on your head and have the students watch very closely as you touch the balloon to the tip of the wire outside of the jar. The two pieces of aluminum foil should move apart.

Van de Graaff - There are alot of things that can be done with the Van de Graff. The most popular activity is to make your hair stand up. We suggest you do this instead of a student. Stand on the milk crate with your hand on the metal dome. Turn it on and let charge build up on yourself. KEEP YOUR HAND ON THE VAN DE GRAFF. When your hair has stood on end for awhile (and the kids have gotten their laughs in), then turn the Van de Graaff off, with your hand still on it. Keep your hand on the metal dome for awhile (about 30 seconds) after turning it off to let the charge dissipate off of you.

Picking things up with magnets - Have a student come up to the table and try to pick things up from the pile of stuff with a magnet. Point out that not everything gets picked up with the magnet (the aluminum foil and styrofoam doesn't get picked up).

Push opposite poles of strong magnets together - Use a pair of the very strong ceramic magnets. Have a student hold the magnet on both ends so that his hands are covering both side of the magnet. You hold the other magnet in the same way. Facing each other try to push the magnet together.

Circular magnets on pencils - Pass around the circular magnets on a pencil.

Compass - Have a student come to the front of the class and hold the compass. Point him in any direction, let the compass stabilize, and have him point his arm in the direction that the compass is moving. Turn him towards another directions, and have him point his arm the direction that the compass is moving. Repeat a couple times until they get the point that his arm (and the compass) are always pointing in the same direction. Then get a magnet out and make the compass needle move with the magnet. The point is to show them that the Earth is a big magnet (not very strong, but big), and that's how it turns the compass needle.

Make an electromagnet - Coil a wire around a nail and connet the two ends of the wire to opposite ends of the battery. Show that when the two ends of the wire are touching the battery, the nail will pick stuff up (like stables and paper clips).

Make an LED light up with magnet - Use the pendulum setup with a magnet and LED. Explain that there is a coil of wire connected to the LED. Emphasize that the LED is NOT plugged into the wall. Swing the pendulum and have them watch the LED closely as it flashes.