Chapter 1
Earth Science
Course: Elementary Education Multiple Subjects 7001
Subject: Elementary Education Science Subtest 7005
Chapter: Physical Science
1. Electricity
Electricity is a form of energy resulting from the movement of electrons, which are negatively charged particles that orbit the nuclei of atoms. It plays a vital role in modern life and has applications ranging from basic lighting to advanced electronics and communication systems.
There are two main types of electricity:
- Static electricity is the result of an imbalance of electric charges on the surface of materials. It typically builds up through friction when two objects rub against each other. For example, rubbing a balloon on hair transfers electrons, creating opposite charges that attract the balloon to the hair or wall. Static discharge occurs when the accumulated charges are suddenly released, such as a shock when touching a metal doorknob.
- Current electricity involves a continuous flow of electric charge through a conductor, usually a metal wire. This flow is driven by a potential difference (voltage) between two points and requires a closed circuit. Current electricity is used in homes, schools, and industries to power devices and systems.