Chapter 5: ElectricityLesson 1:“What Lights the Night?” How do electric charges flow in a circuit? Pgs. 152-157
Words to Know: conductor- a material through which an electric charge can move easily. insulator- a material through which an electric charge moves slowly. electric circuit- an electric charge in motion
series circuit- a circuit in which electrical charge can only flow in one circular path. parallel circuit- a circuit that has two or more paths through which electrical charges may flow.
Background Information • An electric current is the movement of charges through a material. Free electrons move in a certain direction because of potential difference, or voltage. • As a free electron moves, it passes atoms along the way. The electron may become attached to one of these atoms, giving it an extra electron. This atom then gives up an electron that moves on to attach to another atom.
This process continues as the electrons move toward the positive end of a circuit, resulting in voltage. The voltage produces electric current.
ELECTRIC CHARGES Most atoms have three different particles. Some particles have a positive charge (+). Some have a negative charge (-). Some have no charge. Matter usually has the same number of positive and negative particles. Charged particles can move between objects that are close to each other. Static electricity happens when positive and negative charges no longer balance. Static means “not moving”
Most electricity is on the go. An electric charge in motion is called an electric current. An electric current flows quickly and invisibility from one place to another. A conductor is a material through which an electric charge can move easily. Most metals, such as copper, gold, and silver are good conductors. An insulator is a material through which an electric charge moves with difficulty. Plastic, rubber, glass, and dry wood are good insulators.
Circuits For a current to flow, electric charges must complete a loop or circuit. A current cannot flow if the circuit has any gaps or breaks. A cut wire and an off switch are examples of breaks.
Types of Circuits Series Circuit- electric charge can flow in only one circular path. Parallel Circuit- Has two or more paths through which electric chargesmay flow