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Activity

Static electricity: jumping rice crispies

Summary: 
Use a cloth to charge a plastic sheet, and make small objects jump around.
Science content (2016 curriculum): 
Physics: Electricity, Electromagnetism (7)
Lessons activity is in: 
Materials: 
  • shallow tray e.g. shoebox lid
  • sheet of acrylic or other plastic (test it first!)
  • alternative to above items: large petri dish with lid
  • small piece of cloth to charge acrylic sheet or lid of petri dish (plastics seem to work well, also try wool)
  • small objects to pick up e.g. rice crispies, scraps of paper; also add others to test
Procedure: 

Put a few of the small objects in the tray or petri dish.
Put the acrylic sheet over or put the lid on the petri dish.
Rub the top with the cloth.
The small objects will stick to the lid, and sometimes even dance up and down.

Allow students to free play and explore what objects dance and which don't.
They can take notes on what they find.

Maybe give them different cloths to try. Rubbing one's hand on the lid, instead of a cloth: works quite well when the hand is dry.

Sometimes the effect will stop after a while - try turning over the plastic sheet.

Explanation:
When the cloth is rubbed on the plastic lid, electrons are transferred from one to the other (whether the cloth or the plastic lid takes the electrons depends on their relative positions in the "Triboelectric series"). The lid is now charged with a negative or positive charge. The small objects are attracted to this charge and so stick to the lid.

Grades taught: 
Gr 1
Gr 2
Gr 3
Teacher: 
Ingrid
Teaching site: 
General Gordon Elementary Science Club
Activity originally developed and delivered: 

Gordon Elementary Science Club