What is Electrical Charge?What is Electrical Charge?

Electrical charge is not something you can see, smell, or weigh. We know about charge because we can see its effects on matter.

All matter is made up of tiny particles, called atoms. Inside atoms are even tinier particles. Some have a negative electrical charge. Others have a positive electrical charge. A negative electrical charge is shown as a minus sign (-). A positive electrical charge is shown as a plus sign (+).

Electric ChargeElectric Charge

Some particles have a negative electrical charge. Others have a positive electrical charge. Opposite charges attract each other. Like charges repel each other.

Atoms usually have no overall charge. This is because the number of positive charges equals the number of negative charges. However, atoms can become charged. They can pick up electrical charges from other atoms. This can happen when you rub two different materials together – such as balloons and wool.

Rubbing two different materials together knocks negative charges off one material. This makes the material positive. The negative charges collect on the other material, making it negative.

The two materials are now attracted to each other because they have opposite charges. Opposite charges attract. Positives attract negatives. Negatives attract positives. Charges that are the same repel, or push each other away. Two positive charges repel each other. Two negative charges do, too.

The buildup of electrical charge on a material is called static electricity. The electrical charges build up because negative charges have moved from one material to another.

A balloon has no overall charge. There are as many negative charges as there are positive charges. Rubbing the balloon knocks negative charges off the cloth and onto the balloon, making it negative.

The balloon’s negative charges repel negative charges in the wall. This leaves a row of positive charges on the outside edge of the wall. The negatively charged balloon is attracted to the wall’s positive charges and sticks to it.

After a while the negative charges on the balloon “leak” away. The balloon is no longer attracted to the wall. It falls away.

What are two types of What are two types of electrical charges in atoms?electrical charges in atoms?

• Answer the question…– With a partner– In your Learning Notebook

static electricitystatic electricity

• The buildup of an electric charge on a material.

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