What is an electric charge?  Describe the structure & charges in an atom.  Charge- physical property  Charged objects exert a force- push or pull- on other charged objects  Law of electric charges- like charges repel, different charges attract

Electric Force & Field  Electric force- force between charged particles Size depends on amount of charge & distance between charges  Electric field- the region around a charged object in which an electric force is exerted on another charged object  Objects in an electric field react to the electric force

How are objects charged?  Do atoms have a charge?  Friction- electrons are wiped from one object to another Examples?  Conduction- electrons move from one object to another in direct contact Examples?  Induction- charges in an uncharged metal object are rearranged w/o direct contact

Conservation & Detection  Charges are not created or destroyed, only transferred  Electroscope- glass flask w/metal rod in rubber stopper w/2 metal leaves attached.

Moving Charges  Electrical conductors- charges move easily; ex. Metals  Insulators- charges can not move easily, electrons do not flow freely; ex. Plastic, rubber, glass, wood, & air

Static electricity  Electric charge at rest on an object  Static-not moving  Ex. Clothes in a dryer; tumbling causes transfer of charge due to friction; when friction stops, charges are static

Electric Discharge  Loss of static electricity as charges move off an object  May be slow or quick  Ex. lightning