Materials

Metals come from rocks called ores.

They are strong, hard and shiny materials that can be hammered into different shapes without breaking.

Many metals are good conductors of heat and electricity.

Some metals are magnetic. Iron is the most magnetic metal. Steel is also magnetic because it is made of mostly iron.

Their properties make them useful for objects such as cutlery, saucepans, cars and coins.

Plastics are materials made from chemicals and are not found in nature. They are strong and waterproof, and can be made into any shape by applying heat. Plastics can also be dyed different colours or made to be transparent.

Plastic is not magnetic. It is a good electrical insulator as it does not conduct heat or electricity.

Plastics are used to make all sorts of things, such as bags, bottles and toys.

Glass is made by melting sand and other minerals together at very high temperatures.

Glass is normally transparent and can be made into many different shapes. Thick glass can be strong, but thin glass will break very easily.

Glass is used for objects that need to be transparent such as windows and spectacles.

Wood comes from trees. It is strong, flexible and long lasting.

Wood is used to make things such as furniture that need to be strong and last a long time.

Wood is an insulator of heat and electricity.

Fabrics are made from thin fibres woven together.

·         Some fabrics, such as wool, cotton and silk, are natural (the fibres come from living things).

·         Some fabrics, such as polyester and nylons are made from synthetic fibres, which are made in factories, from chemicals.

Different fabrics have different properties. Fabrics can be stretchy (a pair of tights),insulating (keep you warm, like a woollen coat) or absorbent (a towel).

Fabrics are used to make clothes as they are flexible and comfortable, can be warm and do not wear out easily.

http://www.bbc.co.uk/schools/scienceclips/ages/7_8/characteristics_materials.shtml

Material properties

Materials have different properties that make them useful for different jobs. Here are some properties that materials have.

Transparent or opaque

Transparent materials do let light through (you can see through them). Opaque materials do not let any light through (you cannot see through them).

Waterproof

Waterproof materials do not let water through and do not soak up water.

Absorbant

Absorbent materials soak up water and let water pass through them.

Strong or weak

Strong materials are very difficult to break. Weak materials break easily.

Flexible

Flexible materials are easy to bend.

Rigid

Rigid materials are difficult to bend.

Hard

Hard materials are difficult to scratch.

Magnetic

Magnetic materials are attracted to magnets.

Conductors

Some materials are good conductors of heat. This means heat can travel through them easily.
Some materials are good conductors of electricity. This means electricity can travel through them easily.

Insulators

Some materials are insulators of heat. This means they do not allow heat to travel through them very easily. Some materials are insulators of electricity. This means that electricity cannot travel through them.