What is the Static Electricity

Have you ever had your hair stand on end after rubbing a balloon on your hair before a birthday party?

You have probably experienced static electricity!  We experience static electricity very often in our daily lives. Sometimes when you touch a doorknob or other metal object, you get a slight shock.

What has happened?

You have collected extra electric charges by rubbing your feet on the carpet. When you touch metal, these extra charges want to travel to the metal, giving you a shock. Why do charges do this?

There are two types of charged particles that are the building blocks for atoms: positive protons and negative electrons. Charge follow certain laws.

1. All like charges repel (push away from) each other and all unlike charges attract (pull towards) each other.

2. The force exerted gets larger as either charge gets larger, and it gets much smaller as the distance between the charges increases. (You might see some similarities to gravity here.)

As you scuffle your feet along the floor, you can pick up extra electrons. These electrons tend to want to move as far away from each other as they can. As more and more charges build up, each of the hairs on your head can have many extra like charges along the length of the hair. Since like charges repel, the hairs are pushed away from each other and can look like they are floating. This is a fun electrostatic demonstration that is common to science museums and high school physics classes. Anyone can do it if you have access to a Van de Graaff generator and someone who will help you use it safely. As long as the extra charges stay on your hair, it floats. But all these like charges are still pushing away from each other.

If you touch a metal object, a good electrical conductor (i.e., charges move easily on it), the charges will repel and push some of the charges to move towards the metal and then you get a shock.