Activity: Charge It!
Static electricity is the buildup of electric charge on an object.
That charge may be positive or negative, depending on whether the
object loses or gains electrons. It may result from the transfer
of electrons from one object to another or from one location to
another within the same object.
One way electrons get transferred is through friction. For example,
when you rub a balloon against your head, electrons in the atoms
that make up your hair rub off onto the balloon. This loss of electrons
leaves your hair with an overall positive charge. The gain of electrons
leaves the balloon with an overall negative charge.
Charged objects interact in very specific ways. In this activity,
you are going to build up electric charges on balloons and investigate
the forces that they exert on other objects.
- 2 balloons
- scrap of paper
- Blow up a balloon and tie it off. Rub the balloon against your
clean, dry hair for several seconds. Then hold the balloon near
but not touching your head. What happens to your hair?
- The balloon is negatively charged, and your hair is
positively charged. What can you conclude about unlike charges?
- Blow up a second balloon and tie it off. Rub both
balloons against your hair. Place one balloon on the table. Slowly
move the other balloon near it. What happens? What charge do the
- Are there any strands of hair clinging to the balloons?
Pull off two and hold the strands close together. What happens?
What charge do the strands of hair have?
- What can you conclude about like charges?
- Finally, tear up some paper into tiny bits and sprinkle
them on the table. Rub one balloon against your hair. Place the
balloon near (but not touching) the bits of paper. What happens?
- The balloon is negatively charged, but the bits of
paper are neutral (have no charge). What must have happened to
the electrons in the atoms that make up each bit of paper?
In this activity, you are going to build up electric charge
on an object and then discharge it, producing miniature lightning
bolts and thunder.
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