Electric Charge

Atoms Small particles of matter Composed of 3 smaller particles: Protons = positive (+) charge Electrons = negative (-) charge Neutrons = no charge (neutral)

Nucleus (protons & Neutrons) Electrons Atom

Electric Charge Property causing particles to attract or repel each other Transfer of electrons causes objects to become charged –gain electrons = negative charge –lose electrons = positive charge –Unit is Coulomb: amount of charge carried by 6.25 x electrons

Electric Force: attraction or repulsion between charges Like charges Repel Opposite charges attract

Electric Field Effect electric charge has on other charges around it Strength depends on: 1. Amount of charge it produces 2. Distance from the charge –STRONGER WHEN CLOSER –Viewing chargesViewing charges

+ - Electric Field Points outward Points inward

Static Electricity How charges build up and transfer between objects 3 Ways to transfer charge 1. Friction 2.Contact 3.Induction

Charging By Friction Loosely held electrons from one object are transferred to another object by rubbing together –Ex: Rubbing balloon against clothes –Walking across a carpetWalking across a carpet

Charging by contact Object with excess electrons touches a neutral object, electrons are passed to neutral object –Van de Graaff generator: charged sphere. Hair gains electrons

Charging by Induction Transfer of charge without contact –Reaching for a doorknob after walking across carpet –Viewing induction one sphereViewing induction one sphere –Viewing induction two spheresViewing induction two spheres

Static Discharge Sudden release of built up charge –Path must form between objects Examples: –Shock touching doorknob –Lightning (large discharge) –How lightning formsHow lightning forms

Electroscope Device that detects electric charge –Leaves separate if charged