Presenter: Tony Wayne, Albemarle High School, firstname.lastname@example.org
PH.6 The student will investigate and understand that quantities including mass, energy, momentum, and charge are conserved.
Opposite charges attract while like charges repel
To show that fire is low energy plasma consisting of plus and minus charges. And that the charges from plasma can be used to neutralize a net charge.
If you are using the match take the usual precautions regarding fire in the classroom. If you are using the Tesla coil, keep it away from others. It can burn and it does give a severe shock.
Inflate each balloon. Tie a string, about 1 meter long, to each balloon. Tie the loose ends of the string together such that all the balloons touch each other equally when you are holding the string’s end opposite the balloon. Hang or securely tape the strings to the ceiling. Rub each balloon with the fur or wool. They will each acquire the same sign charge, through the triboelectric effect, and be repelled from each other. They will hover away from each other. Take a lit match and hold it about 12 to 18 inches below the balloons. The balloons will drop and come together in about 10 seconds.
How the physics is demonstrated
Fire from the match liberates charges. These charges rise up in the heat of the flame. Charges opposite from the balloon’s net charge will be attracted to the balloon and neutralize the balloons net charge. The charges like the balloon’s net charges will be repelled from the charged balloons.
To extend the demonstration, repeat it using a Tesla coil instead of the match. The balloons will drop even faster this time. The Tesla coil is another excellent source of positive and negative ions.
Construction and Tips Regarding the Demonstration
This is mentioned above.
Sources & References
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