Chapter 18 Study Guide

1. Science Chapter 18 Study Guide

2. The electric force between two charges that are not moving is static electricity. An electric cell uses chemical reactions to create an electrical current. A continuous flow of electric charge through a pathway is an electric current. Vocabulary

3. A conductor carries electric charges well. Plastic and wood are insulators because they do not carry electric charges well. The amount of electric potential energy per unit charge is called the voltage of a battery.

4. Electrical energy can be produced by harnessing wind or solar energy, building dams or nuclear power plants, burning fossil fuels ore rubbing items together. The mechanical energy stored in a battery is known as chemical energy. Checking Main ideas

5. Electricity moves from power plants, through transformers, and then into homes. If a step-down transformer failed to work properly, electricity at too-high a voltage would reach the home that could result in burning out electrical appliances and starting electrical fires. Predict

6. Office workers arrive early and set up the space-heater to warm their feet. One hour later, two more workers arrive and turn on their computers. Within minutes, the lights in the entire office goes out. This might have happened because the heater and computers needed too much energy for the circuit breakers or fuses to handle. Infer

7. The smallest particle of an element that still has the properties of that element is an atom. The atomic particle that has an extremely small mass compared to the others is the electron. The nucleus is the central part of an atom. Chapter 12

8. An atomic particle with a positive charge is called a proton. When two or more atoms are joined together, a molecule is formed. An atomic particle with no charge is called a neutron.