Physical Changes in Matter

What is matter?

Matter is anything that takes up space and has mass. There are three states of matter. Matter can be solid, liquid, or gas. Just about everything that you can see, touch or smell is made up of matter. In fact many things that you cannot see, touch or smell (like air) are also made of matter.

Physical changes in matter

Physical changes in matter involve things like a change in the shape or size of the matter. Some examples are:

Cutting cloth
Sawing a piece of wood

When you saw wood, you get smaller pieces of wood.

Breaking a glass

A glass shatters into smaller pieces of glass.

Tearing paper

Changes from one state of matter to another are also physical changes. Some examples are:

Freezing water

Melting iron

At very high temperatures, iron melts and glows orange. However it is still iron.

Water changing into water vapour

Water vapour is just water in the form of a gas.

Physical changes do not create new substances. For instance, if you tear a piece of paper in two, you will have two pieces of paper. If you break a rock with a hammer, you will end up with smaller pieces of rock. If a glass breaks, you get smaller pieces of glass. If you freeze water, it is still water.

Often, physical changes can be reversed. Look at the examples below:

You can freeze water to get ice. Then you can melt the ice to get water.
Water can be boiled until it turns into water vapour. Then the water vapour can be cooled until it condenses into water.
You can dissolve salt in water. Then you can boil the solution until all the water evaporates, leaving behind the salt.
You can melt iron by heating it to a very high temperature. When it cools down, it will turn back into solid iron.

Once again, it is important to note that physical changes do not cause matter to change into a different substance.