1. ELECTRIC CHARGE • property of matter that creates electric and magnetic forces and interactions. • depends on the imbalance of its protons and electrons. Electrons • negatively charged protons • positively charged neutrons • are neutral (no charge).

2. ELECTRIC CHARGE • Negatively charged objects have more electrons than protons. • Positively charged objects have fewer electrons than protons. SI unit: • coulomb, C.

3. LAW OF CHARGES • Like charges repel • opposite charges attract.

4. ELECTRIC CHARGE ELECTRICAL CONDUCTOR: • material in which charges can move freely and that can carry an electric current. ELECTRICAL INSULATOR: • material that does not transfer current easily.

5. CHARGING BY FRICTION • When an object whose electrons are loosely held rubs against another object, electrons are transferred to the second object .

6. INDUCED CHARGES • Electrons are moved to opposite ends (not by contact) polarization • Alignment of charges at surface of an object producing an electric charge • Positive & negative charges on opposite sides

7. CHARGING BY CONTACT • charge a neutral object by touching it with a charged object. The transfer of electrons to the metal doorknob gives the doorknob a net negative charge. When a negative rod touches a neutral doorknob, electrons move from the rod to the doorknob.

8. STATIC DISCHARGE • movement of electrons to relieve a separation in charge

9. ELECTRIC FORCE • force of attraction or repulsion between objects due to charge. Electric force depends on charge and distance. • proportional to product of charges on objects. • inversely proportional to square of distance between two objects.

10. ELECTRIC FIELD LINES • point in direction of electric force on a positive charge. • positive charge point outward. • negative charge point inward. • never cross one another. • show both direction of an electric field and relative strength due to a given charge. • More lines are drawn for greater charges to indicate greater force.

11. ELECTRIC FIELD LINES

12. ELECTRIC FIELD LINES