Engineering > Electrostatics > How Does Static Electricity Work?

Site: http://www.loc.gov/rr/scitech/mysteries/static.html

Grade Category: Elementary

Subject Category: Engineering

Sub Category: Electrostatics

How Does Static Electricity Work?

static electricity science projectAnswer: Static electricity is an imbalance between positive and negative charges in an object.

Have you ever walked across the room to pet your dog, but got a shock instead? Perhaps you took your hat off on a dry winter's day and had a "hair raising" experience! Or, maybe you have made a balloon stick on the wall after rubbing it against your clothes?

Why do these things happen? Is it magic? No, it's not magic; it's static electricity!

Before understanding this phenomenon, we first need to understand the basics of atoms and magnetism.

All physical objects are made up of atoms. Inside an atom are protons, electrons and neutrons. The protons are positively charged, the electrons are negatively charged, and the neutrons are neutral.

Atom diagram

electrical chargeselectrical chargesTherefore, all things are made up of charges. Opposite charges attract each other (negative to positive). Like charges repel each other (positive to positive or negative to negative). Most of the time positive and negative charges are balanced in an object, which makes that object neutral.

As mentioned earlier, static electricity is caused by an imbalance between negative and positive charges in an object. These charges can build up on the surface of an object until they find a way to be released or discharged. One way to discharge them is through a circuit. The static electricity charge on your body can be enough to light a low current bulb.



The rubbing of certain materials against one another can transfer negative charges, or electrons. For example, if you rub your shoe on the carpet, your body collects extra electrons. The electrons cling to your body until they can be released. As you reach and touch your furry friend, you get a shock. Don't worry, it is only the surplus electrons being released from you to your unsuspecting pet.

And what about that "hair raising" experience? As you remove your hat, electrons are transferred from hat to hair, creating that interesting hairdo! Remember, objects with the same charge repel each other. Because they have the same charge, your hair will stand on end. Your hairs are simply trying to get as far away from each other as possible!

When you rub a balloon against your clothes and it sticks to the wall, you are adding a surplus of electrons (negative charges) to the surface of the balloon. The wall is now more positively charged than the balloon. As the two come in contact, the balloon will stick because of the rule that opposites attract (positive to negative). And thats how static electricity works. Now can you think of an interesting static electricity science fair project?