Tuesday, 13 December 2011

Material properties (Year 5)

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


 Strong materials are very difficult to break.


 Flexible materials are easy to bend.


 Hard materials are difficult to scratch.


 Magnetic materials are attracted to magnets.


     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.


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 that are not found naturally but are made from chemicals.
They are strong and waterproof, and can be made into any shape or colour. Many plastics can be made transparent.
They are not magnetic and do not conduct heat or electricity.
Plastics are used to make all sorts of things such as plastic bags, plastic bottles and toys.

Glass is made by melting sand.
It 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.


   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.