1. 19.1 Notes  Atoms & Charge  Remember, all matter is made up of atoms and atoms are made up of smaller particles!  Protons – have a positive charge  Electrons – have a negative charge  Neutrons – do not have a charge

2. Electric Charge and Static Electricity  Charges can exert forces!!!  A charged object exerts a force (a push or a pull) on other charged objects.  THE LAW OF ELECTRIC CHARGES states that like charges repel and opposite charges attract.

3. Electric Charge and Static Electricity  Did you know? Car manufacturers take advantage of the LAW OF ELECTRIC CHARGES when they paint cars. The car bodies are given a positive charge and the paint droplets are given a negative charge!

4. Electric Charge and Static Electricity  The force between charged objects is an ELECTRIC FORCE. The strength of the force depends on the size of the charge and the distance between charges.  An ELECTRIC FIELD is a region around a charged particle that can exert a force on another charged particle.

5. Electric Charge and Static Electricity  Did you know that Benjamin Franklin introduced the terms positive and negative as they relate to electrical energy, and he invented the lightning rod.

6. Electric Charge and Static Electricity  Objects become charged because they lose or gain electrons.  If electrons are lost, the object becomes positively charged.  If electrons are gained, the object becomes negatively charged.

7. Electric Charge and Static Electricity  There are 3 common ways for an object to become charged:  Friction  Conduction  Induction  The charge on an object can be detected by an electroscope.

8. Electric Charge and Static Electricity  Friction: Rubbing two objects together can cause objects together can cause electrons to be “wiped” from one object and transferred to the other.  Ex: If you rub a plastic ruler with a cloth – electrons are transferred from the ruler. The ruler becomes negatively charged and the cloth becomes positively charged!

9. Electric Charge and Static Electricity  Conduction: Charging by conduction occurs when electrons are transferred from one object to another by direct contact.

10. Electric Charge and Static Electricity  Induction: Charging by induction occurs when charges in an uncharged object are rearranged without direct contact with a charged object.  Ex: A negatively charged balloon induces a positive charge on a small section of wall because the electrons in the wall move away from the balloon.

11. Electric Charge and Static Electricity  When you charge objects by any method, no charges are created or destroyed. Electrons simply MOVE from one atom to another, creating objects or areas with different charges.  Because charges are not created or destroyed, CHARGE IS SAID TO BE CONSERVED.