Electric Charge Chapter 7 1 Charge Atoms are

Electric Charge Chapter 7. 1

Charge • Atoms are made up of: – Positive protons – Negative electrons – If the atom has same number of each, it is electrically neutral

Transferring charge • Electrons are bound more tightly to some atoms – When surfaces are in contact sometimes electrons can transfer between the objects • Accumulation of excess electric charge = static electricity Example: Rubbing the soles of your foot on the carpet transfers electrons to your foot

Conservation of Charge • Charge can be transferred from object to object, but it cannot be created or destroyed

Comparing Forces • Electrical forces > gravitational forces – For protons and electrons • In real life, two objects have a greater gravitational force than electrical force since most objects are neutral • Electrical force directly proportional to charge of objects and inversely proportional square to the distance

Conductors & Insulators • Conductors – Have electrons that are able to move easily • metals • Insulators – Have electrons that are not able to move easily • Wood, rubber, glass

Charging Objects • Charging by contact – Rubbing two materials together resulting in transfer of electrons – One material becomes positive the other negative

Charging by Induction • When charged objects get close to neutral objects, they can cause the neutral object to rearrange the position of its’ electrons – No initial contact required to attract the objects