(Chapter 7, Section 1)

● Atoms have protons, neutrons, and electrons

Protons have a positive charge

   Electrons have a negative charge.  They are on the outside of the atom, and can be transferred. 

●Usually, an atom has the same number of protons and electrons, which means they cancel out and there is no net charge. 

       ● Atoms become charged if they gain or lose an electron. 

● Static electricity is the buildup of excess electric charges. 

● Charge can move from one object to another, but it is NEVER CREATED OR DESTROYED: Law of Conservation of Charge

 

  +               -       Opposite charges attract (think static cling)

   +               +          Like charges repel

                                                                                                                                                                                                                               

● Charges can act at a distance by creating an electric field.

(That means charged objects apply a force even when they’re not touching!)

 

● Electrons move easily through conductors (ex. metals)

● Electrons don’t move easily through insulators (ex. plastic,etc)

 

● Transfer of electric charge occurs in three ways:

● Charging by Contact: rubbing materials together (ex. feet on carpet)

● Charging by Induction: the rearrangement of electrons on a neutral object caused by a nearby charged object (ex. charged balloon near your hair)

● Static Discharge: Transfer of charge through the air between two objects because of a buildup of static electricity (ex. lightning)

 

● Grounding: using a conductor to direct electric charge to the ground

● Charges can be detected using an electroscope.