How are materials classified?

Materials can be classified according to their physical properties. Phyiscal porperties are characteristics that can be measured or observed without changing the identity of the matter. For example, when a piece of copper wire is cut into a few short segments, their ability to conduct electricity remains the same.

The table below shows some physical properties that can be used in the classification of materials. 

How are materials classified? (cont.)

The table below is a continuation of the one above.

Alloys

An alloy is a mixture of a metal with other elements.

The table below shows some examples of alloys and their uses.

Usefulness of Alloys

The figure below shows how alloys are used.

What are some common ways to classify materials?

Materials are specific types of matter used to make useful things. 

There are two main groups of materials - natural and man-made. Materials are classified according to their common physical properties. 

Sometimes, chemical properties of materials are also taken into consideration when choosing them for certain applications. An example would be the ability to resist corrosion (corrosion is the process in which a substance reacts with oxygen in air to form rust). 

Explanation on the Choice of Materials in Making Useful Products

1. A material has more than one physical property.
e.g. Iron is a metal which is a magnetic material, good conductor of heat and electricity, high melting and boiling points and others.

2. When a material is chosen to make a useful product, a few physical properties are taken into consideration which must match its application in the most efficient and effective ways, as shown in the table below.

3. Sometimes the cost of a material can affect the choice of material for making a product. Even though a material may have the best desired physical properties, a cheaper material may become the alternative choice for making a particular product. 

e.g. silver has a higher electrical conductivity than copper but is more expensive than copper. Hence, copper is used to make electrical wires instead of silver.