Static Electricity and Charging Objects

Learning Goals To be able to explain static electricity To be able to explain how to charge objects

Static Electricity An imbalance of electric charge at rest on the surface of an object “Static” means not moving The charge builds up in one place on the object until allowed to suddenly move to another object

Electric Discharge The sudden movement of static charge between two objects Rubbing feet on carpet and touching a doorknob, you feel a shock and may see a small spark Example: lightning

Uses of Static Electricity Static-cling film: static-vinyl film stick on windows using static Photocopier: The pattern is made negatively Toner is positively charged, attracted to the pattern Toner is then transferred to the paper

Charging by Friction Two neutral objects of different materials are rubbed together, electrons transfer from one to the other The object that gains electrons becomes negatively charged The object that loses electrons becomes positively charged

The Electrostatic Series Used to predict the charge produced on each substance Examples: Determine the charge on each object after they are rubbed together. Acetate ____________ Fur ____________ Cotton ____________ Rubber ____________ + -- + --

Charging by Friction The two neutral objects now have two opposite charges

Charging by Contact Charging a neutral object by direct contact with another charged object Electrons move from one object to the other The neutral object becomes charged with the same type of charge as the object that touched it

Conduction between two charged objects Contact causes electrons to be transferred between the objects until the charge is balanced

Charging by Conduction The two objects now have the same charge

Success Criteria I CAN describe static electricity I CAN explain charging by friction and by contact