Ions in action
Make pieces of paper fly through the air and stick onto a balloon.
What you need:
A sheet of paper
A hole punch
What to do:
Inflate the balloon to a size that fits easily in your hand.
Tie a knot in the end of the balloon.
Use the hole punch to cut several small circles from the sheet of paper.
Rub the balloon back and forth gently on your hair about 10 times. Don't press too hard. Your hair should be clean, dry, and oil-free.
Hold the balloon close to, but not touching, the paper circles. Watch what happens.
Why does the balloon pick up the confetti?
Atoms are the teeny tiny particles that make up all matter. Atoms have even teenier pieces, called electrons, that they wear like coats. Sometimes the atom wears all its coats, sometimes it takes off one or more.
When you rub the balloon on your hair, some of the electrons rub off and stick to the balloon. The electrons have a negative ( – ) electric charge, so the balloon has a negative charge. When atoms are missing electrons (they've taken off a coat or two), we say they have a positive ( + ) charge. The confetti you made has a few electrons missing, so has a slight positive charge. Negative and positive charges attract each other. So, the confetti sticks to the balloon!
Atoms that have either a negative or positive charge are called ions.
The Deep Space 1 spacecraft uses an ion engine to propel itself through space.
This engine uses the same law of nature that makes a regular fuel-burning rocket work. (See how to build a pop-rocket.)
The forces of attraction are very strong in ion propulsion. The ions actually move much faster than does the hot gas coming out of a regular rocket engine. So the ion propulsion system works even better!