ACES Activity of the Week: Electric Gelatin - A lesson in static electricity!
We had the best participation this week - 9 parents (all moms) and 6 kids...total 15!!!
Everyone was given a balloon and two tablespoons of gelatin. After the balloons were blown, I asked everyone to hover the balloon over the gelatin which was neatly poured into a pile. Nothing happened...not exciting at all!
Now I asked everyone to rub the balloon against their hair. I got a lot of "are you sure you know what you are doing" looks, especially from the parents, and some giggles from the kids :-)
But very soon, as they saw the hair sticking to balloon, they figured out that I was up to something!
We took the static-laden balloons and hovered the area rubbed against the hair about an inch over gelatin powder.
A few gelatin particles flew up and got stuck to the balloon. The remaining powder on the table stood up into what looked like many mini towers, and when moved, the balloon the towers followed the balloon.
We then touched the powder with the balloon.
Observations:Gelatin powder stuck to the balloon and formed strings depending on how great the charge was.
Analysis:We discussed why it happened - when the balloon was rubbed against the hair, electrons (negatively charged particles) moved from the hair to balloon. The negatively charged particles of the balloon attracted the positively charged particles in the gelatin. This attraction created the gelatin towers that we can see and, if silent, the crackling sound we can hear.
More experiments to try:
1. Take the charged balloon and touch the wall. What happens and why?
2. Place a ping pong ball on a table and take the charged balloon close to it. What happens and why?
3. Blow bubbles and take a charged balloon close to the balloons, What happens and why?