Chapter 13: Electricity Section 13.1: Electric Charge Table of Contents Chapter 13: Electricity Section 13.1: Electric Charge

Positive and Negative Charge Electric Charge 1 Positive and Negative Charge (A)Protons and electrons have electric charge, and neutrons have no electric charge.

Positive and Negative Charge Electric Charge 1 Positive and Negative Charge Protons have (B)positive electric charge and electrons have (C)negative electric charge.

Positive and Negative Charge Electric Charge 1 Positive and Negative Charge Objects with no net charge are said to be (D)electrically neutral.

Opposite charges attract Electric Charge 1 Charges Exert Forces Unlike charges (E)attract each other, and like charges (F)repel each other. The force between electric charges also depends on the distance between charges. An (G) electric field surrounds every electric charge Opposite charges attract Like charges repel

Conductors 1 The (H)best electrical conductors are metals. Electric Charge 1 Conductors The (H)best electrical conductors are metals. The atoms in metals have electrons that are able to move easily through the material.

Insulators 1 (J)plastics, wood, and air are insulators. Electric Charge 1 Insulators (J)plastics, wood, and air are insulators. The plastic coating around electric wires prevents a dangerous electric shock when you touch the wire.

Lightning 1 Lightning is a large (K)static discharge. Electric Charge 1 Lightning Lightning is a large (K)static discharge. A static discharge is a (L)transfer of charge between two objects because of a buildup of static electricity.

Current and Voltage Difference Electric Current 2 Current and Voltage Difference Electric current is measured in (A)amperes.

Electric Current 2 Voltage Difference In a similar way, electric charge flows when there is a (C)voltage difference. A voltage difference is related to the force that causes electric charges to flow. Voltage difference is measured in (D)volts.

Resisting the Flow of Current Electric Current 2 Resisting the Flow of Current All materials have (E)some electrical resistance. Electrical (F)conductors have less resistance than insulators. Resistance is measured in (H)ohms ().

Resisting the Flow of Current Electric Current 2 Resisting the Flow of Current As temperature goes up, resistance goes up As length goes up, resistance goes up As thickness goes up, resistance goes down

Electric Current 2 Ohm’s Law

Calculating Electric Power Electrical Energy 3 Calculating Electric Power The reason why electrical energy is useful is that it is (A) transferred easily into other types of energy. . The unit for power is the watt (W). Because the watt is a small unit of power, electric power is often expressed in kilowatts (kW). One kilowatt equals 1,000 watts.

Electrical Energy 3 Electrical Energy Electric companies charge by the amount of electrical energy used, rather than by the electric power used. Electrical energy usually is measured in units of kilowatt hours (kWh) and can be calculated from this equation:

The Cost of Using Electrical Energy 3 The Cost of Using Electrical Energy The (C2) cost of using the appliance can be computed by multiplying the electrical energy used by the amount the power company charges for each kWh.