There are many types of materials: 

• Brick
• Cardboard
• Ceramic
• Chalk
• Cork
• Fabric
• Glass
• Leather
• Metal
• Paper
• Plastic
• Rubber
• Stone
• Wax
• Wood
• Wool

All materials have different properties. We can group materials according to their properties. Understanding the properties of materials helps us to make decisions about the type of materials we should use for particular jobs. 

The five material properties are:

• Hardness
• Solubility
• Transparency
• Conductivity of electricity
• Conductivity of heat

Some materials can have only one of these properties, or they can have more than one. 

What is hardness?

Hardness is a measure of how difficult it is to break, scratch or bend something. Hardness is important when something needs to be very tough. Soft materials are required when softness and flexibility are important.

A rock is an example of a hard material.

A pillow is an example of a soft material.

What is solubility?

Solubility is the ability to be dissolved. Some materials are able to dissolve in water and some aren’t. Soluble materials dissolve and are usually used in food and in some medical products. Insoluble materials can’t dissolve.

Sugar is an example of a soluble material.

Sand is an example of an insoluble material. 

What is transparency?

Transparency is a measure of how much light a material allows to pass through.  Different materials allow different amounts of light to pass through them depending on the level of light allowed through. Some materials are see-through and some are not see-through. The material can be transparent, translucent, or opaque. 

Transparent refers to a material that allows all or most light to travel through. It is possible to see clearly through transparent materials.

Glass is an example of a transparent material.

Translucent refers to a material that allows some light to pass through. It is not possible to see through translucent materials.

Tissue paper is an example of a translucent material.

Opaque refers to a material that blocks all light passing through. It is not possible to see through opaque materials at all. Opaque materials create shadows when they block light.  

Wood is an example of an opaque material.

What is conductivity of electricity?

Conductivity of electricity refers to the ability to allow electricity to flow through. Some materials allow electricity to flow through and some don’t. Electrical conductors allow electricity to flow through them, and they’re usually used when electricity is needed to be transported from one place to another place.

Copper wires are examples of materials that conduct electricity.

Electrical insulators are materials that prevent the flow of electricity through them.

Plastic is an example of an electrical insulator. 

What is conductivity of heat?

Conductivity of heat  refers to the ability to allow heat to flow through. Some materials allow heat to flow through and some don’t. Thermal conductors allow heat to travel through them and are used when heat is needed to be transported to another place.

Metal saucepans are examples of good head conductors. 

Thermal insulators are materials that don’t allow heat to travel through.

Rubber is an example of a thermal insulator.

Thermal conductors and thermal insulators are also known as heat conductors and heat insulators.