Read the Following Selection
Read the following selection, or click on the play button below to listen aloud.
States of Matter

A rock is a solid, a rock will not take on the shape of a container.
Anything that has mass and takes up space is matter. Matter can exist in three different states—solid, liquid, or gas. Each of these states has different properties.
Solids
A solid holds its shape. For example, a rock is a solid. If you put a rock in a box, the rock will not take on the shape of the box.
Solids have a definite volume. The volume of a solid does not change. (Remember that volume is the amount of space that matter takes up.) A solid always takes up the same amount of space.
Liquids
Liquids take on the shape of the container they are in. For example, a fishbowl and an aquarium have different shapes. When you pour water into each container, the water takes on the shape of the container.
Liquids have a definite volume. Even though the shape of a liquid can change, it always takes up the same amount of space. Imagine that you fill a fishbowl with water. Then, you pour the water into an aquarium. The shape of the water changes, but its volume does not.

When you pour water into each container, the water takes on the shape of the container.
Gases

Steam from a boiling kettle is an example of a gas.
Most gases are invisible. We cannot see the air we breathe, but air is made up of different gases. When wind blows, we can feel these gases moving against our skin. Steam from a boiling kettle is a gas.
Gases do not have a definite shape. They take on the shape of the container they are in.
Gases do not have a definite volume. If you put a small amount of gas into a large container, the gas will spread out to fill the container.
Comparing Properties of Solids, Liquids, and Gases
Use the table to describe and compare the shape and volume of each state of matter.
State |
Shape |
Volume |
Solid |
holds its shape |
has a definite volume |
Liquid |
takes on the shape of its container |
has a definite volume |
Gas |
takes on the shape of its container |
does not have a definite volume |
Now, show what you know!
Complete some questions about the reading selection by clicking “Begin Questions” below.