What are materials made of? Materials and properties.

What are materials made of?

1. Solids, liquids and gases

page 2

Materials and properties


		We are all used to describing things around us as being solid, liquid or gas. These are the three states of matter. You will have some general ideas about what each state of matter looks like and how it behaves. That's how you decide whether to call a material a solid, liquid or gas.

Photo of weightlifter

Picture 1.1. A strong man. What about the can? What are its properties?


	Some properties of solids, liquids and gases
		We use the word property to describe one aspect of what a material is like. Some words we use to describe the properties of materials are: strong, hard, flexible, runny and compressible. Let's look at some of the properties that help us to decide on whether a material is a solid, liquid or gas.

Solids	Liquids	Gases
Keep the same shape	Take the shape of the container	Fill the whole container
Stay where they are put	Runny - can be poured	Spread out quickly
Are difficult to move through	Are quite easy to move through	Are very easy to move through
Can’t be compressed	Are very difficult to compress	Compressible - easy to compress

Photo of pond

Picture 1.2 . The water in the pond fills the shape of the hole in the ground.


	Being flexible about properties
		The trouble with the ideas shown in the table is that they are not perfect. The descriptions don't work for all solids, liquids and gases. This doesn’t mean that the ideas are of no use, but it does mean we have to take care how we use them. Sometimes a material only has some of the properties in the table. And sometimes a material has the properties of more than one of the states of matter.