1. STATIC ELECTRICITY LAB
Init 9/2/2014 by Daniel Barnes
(Based on a very old lab I’ve been doing for YEARS.)
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2. Before any rubbing happens,
What charge is the balloon?
neutral
Before any rubbing happens,
What charge is her hair?
neutral
Why?

3. Matter is usually made of
equal numbers of
positive and negative charges

4. When you rub a balloon on hair, the rubber and the protein have a tug of war over the electrons and the rubber wins.

5. OPPOSITES ATTRACT Now, the balloon is . . . negatively charged.
And her hair is . . .
positively charged.
I just had my hair did!
It cost MONEY!
So her hair . . .
reaches out and
clings to the balloon!
Actually, I was thinking . . .
You know what they say . . .
OPPOSITES ATTRACT

6. But what about when the balloon attracts stuff
that never got rubbed?
Why should a negative balloon attract neutral objects?
They aren’t positive!
The pepper chunks have just as much positive as negative. Why should they feel anything at all?
Tiny chunks of pepper 

7. The protons would like to move up, but they’re stuck in place.
When you bring a negative balloon close to a neutral object . . .
The electrons in the neutral object move away from the balloon.
The protons would like to move up, but they’re stuck in place.

8. So, even though it’s still neutral, the chunk of pepper is said to be
“charged by induction”.
The chunk of pepper is still neutral, since it has just as many positives as negatives.
However, now, the charges are unevenly distributed.
The uneven distribution of electric charges is what makes the attraction possible.
Let’s talk about that a second . . .

9. Shouldn’t those forces cancel each other out?
Well, they would if they were equal in strength . . .
The protons in the neutral object are attracted to the negative balloon . . .
. . . But the electrons are repelled by the balloon

10. Just as with gravity, electrical forces get weaker with distance.

11. Therefore, since the protons in the chunk of pepper are closer to the negative balloon . . .
The attraction up is stronger than the repulsion down, so the pepper leaps up onto the balloon.

12. Bastante para ahora