Unit 11 — Matter and Energy

Welcome back!

Everything you can see, touch, and hold is made of matter.

Matter is all around us.

The air you breathe, the water you drink, the chair you sit on, and even your own body are made of matter.

Today we will learn about matter and some of the forms of energy we experience every day.

What Is Matter?

Matter is anything that has mass and takes up space.

Examples include:

• rocks
• water
• trees
• animals
• books
• air

Matter comes in different forms called states of matter.

Solids

A solid keeps its own shape.

Examples include:

• a book
• a pencil
• a rock
• an apple

Solids do not easily change shape unless a force acts on them.

Liquids

A liquid flows and takes the shape of its container.

Examples include:

• water
• milk
• juice
• soup

Liquids have a definite amount, but they do not have their own shape.

Gases

A gas spreads out to fill the space around it.

Examples include:

• air
• water vapor
• helium

Most gases cannot be seen, but they are still matter.

What Is Energy?

Energy is what makes things happen.

Energy allows things to:

• move
• grow
• produce light
• make sound
• create heat

Without energy, nothing could change or move.

Light

Light helps us see the world.

Some sources of light include:

• the Sun
• stars
• light bulbs
• candles
• flashlights

Plants also use sunlight to make their food.

Heat

Heat is a form of energy that warms objects.

Heat comes from many sources, such as:

• the Sun
• ovens
• fireplaces
• heaters

Heat can cause ice to melt and water to become warm.

Sound

Sound is made when something vibrates.

We hear sounds from:

• people talking
• birds singing
• musical instruments
• thunder
• bells

Our ears detect these vibrations and send messages to our brains.

Activity

Look around your home or classroom.

Find:

• three solids
• three liquids
• one gas

Then list:

• two sources of light
• two sources of heat
• two things that make sound

Practice

Answer these questions.

What is matter?

Name the three states of matter.

Which state keeps its own shape?

Name three sources of light.

How is sound produced?

Review

Today you learned:

• matter is anything that has mass and takes up space
• matter exists as solids, liquids, and gases
• energy allows things to happen
• light, heat, and sound are forms of energy
• energy is part of everyday life

Understanding matter and energy helps explain many of the changes we observe around us.

Looking Ahead

Next we will explore Earth and weather.

We will discover how land, water, air, and weather work together to shape our planet.