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Contributed By: The Bakken Library and Museum
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Experiment Category:
Objective:
Investigate static electricity as you create a waterless snow globe.
What You Need:
- Clear plastic cup
- Teaspoon of confetti (e.g. small pieces of aluminum foil, or tissue that is this size or smaller)
- Wool or fleece (e.g. a sock, hat or mitten)
- Inflated rubber balloon
- Metal tray or pie plate at least as big as the top of the cup (use cardboard wrapped in aluminum if an aluminum tray is not available)
To Do and Observe:
1. Place the confetti in a pile on the tray.2. Turn the cup upside down over the confetti. 3. Vigorously rub the balloon with the wool. 4. Make confetti fly! Try each of these techniques:- Bring the balloon near the cup (don’t touch it), and then take it away.- Touch the balloon to the top of the cup, and then take it away quickly!- Try to find your own way of making the confetti move!5. Make the Waterless Snow Globe:Make a scene using non-metallic materials like small plastic animals, paper or pompoms.Tape or glue the scene onto the tray. Be careful not to cover all the metal. Put confetti into the scene. Place the cup over the scene. Make sure that the scene doesn’t touch the sides of the cup. Glue the cup down if you want. Use the balloon to make the confetti-snow float over your scene.
What's Going On:
In this activity, the confetti starts flying because of static electricity. Static electricity is created when materials are rubbed against each other and electrons are transferred from one material to another. To make the confetti fly, you rubbed the balloon with the wool material. Electrons, negatively charged atomic particles, were rubbed off the surface of the wool and relocated to the surface of the balloon. When the wool lost some electrons it became positively charged and the gaining of electrons resulted in a negative charge on the balloon. As you place the “charged” balloon near the cup the confetti seems to jump towards the balloon. The confetti molecules are neutral, their atoms contain protons (positive charge) and electrons (negative charge) in balance. The negative charge of the balloon repels the electrons, slightly, and attracts the protons, slightly. The closer positive charges have a greater effect, this creates the attraction between the confetti and the balloon. Placing the plastic cup and confetti on the metal plate sustains the charge of the objects instead of grounding them.
Parent/Teacher Tips:
For Younger ChildrenThe science of what is happening with this activity is a bit advanced for younger participants, but it is still lots of fun. A simple introduction to static electricity would be to have a volunteer rub the balloon on their clothes (if they are wearing natural materials) and then place the balloon near his head and the head of a child and observe what happens. The children can then make predictions about what they think will happen when they use the confetti. For Older ChildrenAfter the children have done the initial activity have place the confetti and the cup on a non-metallic surface and try the activity again. Does the confetti jump as it did before? The children could also try rubbing the balloon with different materials to see which “charges” the balloon the most.