Static Electricity!

4th Graders had an electric experience today as we explored static electricity.  It was.....

Electrifying!

When two different substances rub together, one of them gives its electrons to the other (depending on what each is made out of.)    When electrons move, the substances become changed.

When you rub a plastic spoon with a bag, the spoon transfers electrons to the bag.  Electrons have a negative charge, so the bag becomes negative.  Since the spoon loses electrons (negatives) it becomes positive. 

When a spoon is rubbed with wool, the wool gives its electrons to the spoon.  The spoon becomes negative and the wool becomes positive.

When the charged ends of the spoon are brought together, they work a lot like magnets as long as there isn't too much friction.  Likes repel, and opposites attract.  We hung the spoons off the desks and watched them spin!

Check out our Van de Graaff machine!  The machine uses belts and different substance to rub the electrons off and make a positively charged dome.  The styrofoam balls are attracted at first (neutral is attracted to charged).  Once the electrons are taken from the styrofoam balls, they become positive and styrofoam balls fly off.  All of this happens quickly.

Electrons will transfer from you too if you touch the machine.  Shocking!

We also polarized a can.  When you polarize an object, the electrons are not transferred, they just move within the object.  To start this, we rubbed styrofoam on the carpet which DID transfer elections to the styrofoam.  We put a can on the styrofoam.  The can becomes polarized (the electrons don't transfer, they just separate and move away from the negatively charge styrofoam.)

Then when you touch one wire of the static light (filled with neon) to the top of the can, the electrons flow through the wire to your hand!

Now the can is positively charged!  If you lift the can it will gather electrons from the air surrounding and become neutral again.  Then you can place it back on the styrofoam and do it again!  One class had a record of 100 times their light worked!

Check out this site which explores static electricity at Interactive Plasma Physics Education Experience.

interactive static activity

Family Fun has some simple experiments you can try at home!

Family Fun experiments