Vocabulary

• charge: a positive or negative electrical property

• circuit: a path that electricity flows through

• conductor: material that lets electricity flow easily

• electric cell: device that changes chemical energy into electrical energy

• electric current: flow of electric charges (electrons)

• electric fields: area around a charged object where electric force acts

• electromagnet: magnet made by electric current flowing through wire

• insulator: material that does not let electricity flow easily

• magnet: object that attracts iron and some metals

• magnetic field: area around a magnet where magnetic force acts

• magnetic pole: the north or south end of a magnet

• parallel circuit: circuit with more than one path for current

• resistor: material or device that slows electric current

• series circuit: circuit with only one path for current

• static electricity: buildup of electric charges on an object

Critical Thinking

1. What kind of electricity is caused by friction?
   Static electricity.

2. How are charged particles affected when objects are rubbed together?
   Electrons move from one object to another.

3. How is current electricity produced?
   By a continuous flow of electrons through a circuit.

4. What is a circuit? What are the parts?
   A circuit is a complete path for electricity.
   Parts: power source, wires, switch, load/device.

5. Four parts of a circuit:

• Battery/electric cell

• Wires

• Switch

• Light bulb/device

1. Complete vs incomplete circuit:

• Complete (closed): electricity flows

• Incomplete (open): electricity cannot flow

1. How does a flashlight produce electricity?
   Batteries push electrons through wires to the bulb, making light.

2. Three ways to make electricity:

• Friction

• Chemical reactions

• Magnetism/moving turbines

1. Hydroelectric power plant:
   Moving water spins turbines which turn generators.

2. What shows a magnetic field?
   Iron filings or a compass.

3. Difference between poles:
   North and south poles attract each other. Same poles repel.

4. Magnetized vs unmagnetized iron:
   Magnetized iron has particles lined up. Unmagnetized iron has particles random.

5. How is magnetism used to produce electricity?
   Moving magnets near coils of wire creates electric current.

6. Uses of electromagnets:
   Cranes, speakers, doorbells, motors, MRI machines.

7. How are electricity and magnetism alike?
   Both involve forces and moving electrons.

8. Compass near electromagnet switched on:
   The compass needle moves because of the magnetic field.

Conductors and Insulators

Conductors

Materials electricity moves through easily.

Examples:

• Copper

• Aluminum

• Silver

Insulators

Materials that do not conduct electricity well.

Examples:

• Rubber

• Plastic

• Wood

Basic Circuits

Open and Closed

• A continuous flow of charges creates an electric current.

• The pathway is a circuit.

• Closed circuits allow movement of electricity.

• Open circuits stop movement of electricity.

Series and Parallel

• In a series circuit there is one pathway.

• In a parallel circuit there are two or more pathways.

Static Electricity

• Rubbing materials together creates static electricity.

• Lightning is the discharge of static electricity in the atmosphere.

Transforming Electrical Energy

Electrical energy can change into:

• Heat energy

• Light energy

• Sound energy

Examples:

• Toaster → heat

• Light bulb → light

• Speaker → sound

Electromagnets and Electricity

• Magnetism is another form of energy created by moving electrons.

• Electricity and magnetism are related.

• Electric current creates a magnetic field.

• Moving magnetic field creates an electric current.

Magnets are made from:

• Iron

• Nickel

• Cobalt

Magnet facts

• Magnets have two ends called poles.

• North and south poles are attracted to one another.

Types of magnets

• Permanent magnets are always magnetic.

• Electromagnets are temporary magnets.

Electromagnet

• Current through a wire creates a magnetic field.

• Wrap wire around iron and connect to a battery to make an electromagnet.

Strength changes by:

• More wire coils

• Stronger current

Famous Scientists

Benjamin Franklin

Proved lightning was electricity.

Michael Faraday

Discovered relationship between electricity and magnetism.

Thomas Edison

Improved the electric light bulb and power systems.

Extra Questions

What is static electricity?

Buildup of electric charges on an object.

What happens when object gains or loses charges?

It becomes positively or negatively charged.

Like and unlike charges

• Like charges repel

• Unlike charges attract

What is current electricity?

Flow of electrons through a circuit.

Examples of current electricity

• Flashlight

• TV

• Phone charger

Which circuit lets electrons flow?

Closed circuit.

Three needed for a circuit

• Energy source

• Conducting path

• Device/load

Purpose of plastic coating on wires

It insulates and protects from electric shock.

Series circuit bulb goes out?

All bulbs go out because there is one path.

Parallel circuit bulb goes out?

Other bulbs stay on because there are multiple paths.

How many poles does a bar magnet have?

Two.

Strongest part of magnet?

At the poles.

Permanent vs temporary magnets

Permanent stay magnetic. Temporary only magnetic for short time.

Turn iron nail into electromagnet

Wrap wire around nail and connect battery.

Why electromagnet temporary?

Only magnetic when current flows.

Electromagnets vs bar magnets

Both create magnetic fields. Electromagnets need electricity.