Unit 12 — Electricity and Magnetism

Welcome back!

Have you ever flipped a light switch, used a flashlight, or played with a magnet?

Electricity and magnetism are invisible forces that affect our lives every day.

They power our homes, help us communicate, and make many modern technologies possible.

Today you will discover some of the basic ideas behind electricity and magnetism.

What Is Electricity?

Electricity is a form of energy produced by moving electric charges.

We use electricity every day to power:

• lights
• computers
• refrigerators
• televisions
• phones
• washing machines

Without electricity, many of the devices we depend on would not work.

Sources of Electricity

Electricity can come from many sources.

Some common sources include:

• power plants
• solar panels
• wind turbines
• hydroelectric dams
• batteries

Different sources produce electricity in different ways.

Many communities use more than one source.

Electric Circuits

An electric circuit is a complete path through which electricity flows.

A simple circuit usually includes:

• an energy source (such as a battery)
• wires
• a switch
• a device that uses electricity (such as a light bulb)

If the circuit is broken, electricity cannot flow.

When the circuit is complete, the device works.

Conductors and Insulators

Some materials allow electricity to flow easily.

These are called conductors.

Examples include:

• copper
• aluminum
• silver

Other materials resist the flow of electricity.

These are called insulators.

Examples include:

• rubber
• plastic
• glass
• dry wood

Insulators help keep people safe around electricity.

What Is Magnetism?

Magnetism is a force that can attract or repel certain materials.

Magnets have two poles:

• north
• south

Like poles repel each other.

Unlike poles attract each other.

Magnetic Materials

Not every material is magnetic.

Materials that are commonly attracted to magnets include:

• iron
• steel
• nickel
• cobalt

Many everyday objects contain these metals.

Earth as a Magnet

Earth itself acts like a giant magnet.

A compass works because its needle aligns with Earth's magnetic field.

This helps people find directions such as:

• north
• south
• east
• west

Compasses have been important navigation tools for centuries.

Electricity and Magnetism Together

Electricity and magnetism are closely connected.

Electric motors use both electricity and magnetic forces.

Many everyday devices rely on this relationship, including:

• fans
• washing machines
• electric vehicles
• power tools

Scientists continue to discover new ways to use these forces.

Safety Around Electricity

Electricity is useful, but it can also be dangerous.

Always remember to:

• never place objects into electrical outlets
• keep electrical devices away from water
• avoid damaged cords
• follow instructions from trusted adults
• report damaged electrical equipment

Safe habits help prevent injuries.

Activity

Build a simple circuit using a battery, wires, and a small light bulb if materials are available.

Observe:

• what happens when the circuit is complete
• what happens when the circuit is broken

Then test several household objects to predict whether they are magnetic.

Record your observations.

Practice

Answer these questions.

What is electricity?

Name four sources of electricity.

What is an electric circuit?

What is the difference between a conductor and an insulator?

How do magnets attract and repel?

Why does a compass point north?

Review

Today you learned:

• electricity is a form of energy
• electric circuits allow electricity to flow
• conductors and insulators have different properties
• magnets produce magnetic forces
• Earth has a magnetic field
• electricity and magnetism work together in many technologies
• electrical safety is important

Electricity and magnetism are powerful forces that help make modern life possible.

Looking Ahead

Next we will explore Earth's systems, weather, and climate, learning how our planet changes over time and how scientists study the environment.