Electric Charges Protons have a + charge Electrons have a – charge Neutrons have no electric charge The protons and electrons of an atom

are attracted to each other. They both carry an electrical charge

ELECTRIC CHARGES Positive charge of the protons and the

negative charge of the electrons are equal.

ELECTRIC CHARGE MOVES FROM ONE ATOM TO ANOTHER.

What causes static electricity?

When materials are rubbed against each other electrons are pulled from the surface of one material and relocated on the surface of another

When the atom gains or looses an electron it has an electric charge

Static Electricity The accumulation of excess charges on

an object

Opposites Rule of Static Electricity

1. opposite charges attract2. Like charges repel

Have you noticed that clothes sometimes cling together when removed from the dryer? While the clothes tumble

around, electrons are transferred from fabrics that hold their electrons loosely to those that hold their electrons tightly.

Clothes that gain electrons become negatively charged and cling to clothes that have lost electrons and are positively charged

Law of Conservation of Charge Charge can be transferred from object

to object, but it cannot be created or destroyed.

Conductors and InsulatorsConductors

Electrons can move easily through conductors.

Good conductors : skin, copper, gold, silver

InsulatorsA material that doesn’t allow electrons to move through it easily

Good insulators are : plastic, wood, rubber, glass

Transferring Electric Charge The process of transferring charge by

touching or rubbing is called charging by contact. One object will be positively charged and one will be negatively charged.

Charging at a DistanceCharging by induction The rearrangement of electrons on a

neutral object caused by a nearby charged object.

An object charged by induction does not loose or gain electrons, the charged object brought near a neutral object repels the electrons of the neutral object

Lightning Lightning is a

large static discharge. A static discharge is a transfer of charge through the air between 2 objects because of the build up of static electricity

Thunder Lightning also generates powerful sound

waves. The electrical energy in lightning bolts

rip electrons off atoms in the atmosphere and produces great amounts of heat. the heat causes the air in the bolts path to expand rapidly, producing sound waves that you hear as thunder

Electroscope Detects electric

charges

2 thin metal leaves attached to a metal rod

1. A negatively charged object touches the rod

2. The leaves repel if they become negatively charged