http://www.mos.org/sln/toe/staticintro.html
Best Balloon Friends Forever
Materials:
- Balloons
- String
- Felt-tip markers (permanent)
- Adhesive tape
- Wool cloth
Blow up a balloon, draw a face on it, hang it on something high. Rub a piece of wool cloth on the face side of the balloon. Walk toward the balloon. It should face you. Tell them that balloons like mad scientists!
Explain about static electricity. Ask them how we would figure out:
- How far away you can get.
- Does a piece of paper interfere with it?
- Can you make the balloon follow you round and round in a circle?
- How will it react to a second balloon.
A balloon rubbed with a wool cloth becomes negatively charged. When a charged balloon is held close to certain items, the items become positively charged by induction and cling to the balloon. After several minutes, some of the electrons may drain off the balloon onto the items and they'll drop off the balloon and back to the table. They may then transfer their excess electrons to the table after a few minutes and once again leap toward the balloon.
Things it works with: bits of paper, styrofoam bits, loose tea, pepper. Use paper or styrofoam because few are allergic to this.
Styrofoam peas or mylar bits tubes (possible take-home)
- Set up one corner of the room in which students will come to make their static tubes in small groups.
- Give each student a clear plastic tube and end cap.
- Place all of the Styrofoam peas (better than mylar, but mylar's easy to get) inside a large container such as a bowl, shoe box, or can. Challenge the students to get about two capfulls inside their static tubes through the end that they have left uncapped. This is not always easy, because the plastic tubes take on a charge with minimal handling and will attract and repel the Styrofoam peas.
- When the students have placed their peas inside the tube, have them insert the other end cap, and remove any Styrofoam clinging to the exterior of the tube with a cupped hand. Rub the exterior of each tube with the wool cloth.
- Let the students experiment with their closed static tubes. Can they pour all of the peas from one end to the other? How can they move any peas along that seem to be stuck? Using terms they have learned through other activities, such as attract, repel, static charge, and induction, can they describe what happens when they bring a finger close to the outside of the tube?
