Electric Charge

All matter is made up of very small particles called atoms

The center nucleus of the atom is made of particles called protons and neutrons Protons = positive charge Neutrons = neutral charge

Electrons swarm around the outside and have a negative charge Because everything is made of atoms

Most atoms by themselves are neutral The # of protons = the # of electrons

Electrons are held loosely and can be removed making the atom have a positive charge or a negative charge Gains Electron

Charged objects exert a push or pull on other charged objects All objects can have a positive charge, a negative charge, or no charge Charged objects exert a push or pull on other charged objects

Law of Electric Charges Like charges repel and opposite charges attract

The force between charged objects is an electric force Determined by 2 things: Amount of charge Distance between charges

Charged objects are affected by electric force because they have an electric field around them Electric field – space around the object in which other objects can be affected by its electric force

Repulsive Force Attractive Force

How do you charge an object? An object becomes positively charged when it loses electrons, and an object becomes negatively charged when it gains electrons How do you charge an object?

3 ways to charge an object: Friction Conduction Induction

Friction Electrons are “wiped” from one object to another

Conduction Electrons move by direct contact from a charged object to a neutral object

Induction Charges in a neutral object are rearranged without direct contact to a charged object

Friction, Conduction, and Induction

Conservation of Charge Charges aren’t created or destroyed, they are only transferred

a device used to see if something is charged Electroscope a device used to see if something is charged Glass flask with a metal rod through its rubber stopper Two metal leaves are attached to the bottom of the rod

Electroscope Not charged – leaves hang straight down Charged – leaves spread apart

* Cannot tell if the charge is positive or negative Electroscope * Cannot tell if the charge is positive or negative