Materials
• Materials are the matter that objects are made from.
• Some common materials are wood, plastic, metal, rubber and glass.
• Objects can be made of one or more materials.
• Materials can be classified into two categories: natural materials and
man-made materials.
Natural Materials
Natural materials are obtained from plants, animals, earth and sea.
Natural Materials obtained from plants
Wood
• It is obtained from the trunks of big trees such as pine, eucalyptus and
tecoma.
• Examples of objects made from wood are: chairs, tables, cupboards,
chopping boards and pencils.
• Paper is a material which is obtained from wood.
Natural Materials obtained from plants
How is wood obtained?
• The trunks of trees are felled and cut into planks at the sawmill.
Properties of wood
• It is hard and strong.
• It is malleable.
• It is durable.
Natural Materials obtained from plants
Cotton
• It is collected from the pod of the cotton plant.
How is cotton used?
• It is used to make thread.
• The thread is then woven into cloth.
Natural Materials obtained from plants
Properties of cotton
• It absorbs sweat and water well.
• It is soft.
Advantages of cotton
 Since cotton absorbs water well, it is used to make towels, t-shirts and
mops.
 Since cotton is soft, it is used to make garments which are light and
comfortable to wear.
Natural Materials obtained from plants
Rubber
• It is obtained from the rubber tree.
• Latex is a milky liquid which is collected from the rubber tree.
• Latex is processed into rubber in factories.
• Examples of objects made from rubber are: elastic bands, erasers and
tyres.
Natural Materials obtained from plants
Properties of rubber
• It is elastic.
• It is tough.
• It is water repellent.
• It is an insulator.
 Note: Insulators are materials that do not allow electricity to pass through
them
Natural Materials obtained from animals
• Silk is a thin thread extracted from the cocoon of the silkworm or larva
of the silk moth.
• The larva of the silk moth is called Bombyx.
• The cocoon of the silkworm is a silk cover that young moths make to
protect themselves while they are growing.
• Examples of objects made from silk are: dresses, ties and scarves.
Natural Materials obtained from animals
Properties of silk
• It is strong
• It is soft.
• It can be stretched.
• It absorbs sweat well.
Natural Materials obtained from animals
Similarities between cotton and silk
 They are both used to make a thread which is then woven into cloth.
Why some people prefer silk over cotton?
• Silk absorbs water better than cotton.
• Silk cloth is more durable than cotton cloth
Note: Clothes made of pure silk are very expensive.
Natural Materials obtained from animals
Wool
• Wool comes from sheep, woolly goat and angora rabbit.
• Shearing is the process whereby wool is removed from the skin of the
animal.
• Wool is turned into yarns in factories.
• Examples of objects made from wool are shirts, blankets and mats.
Natural Materials obtained from animals
Properties of wool
• It is soft.
• It is flexible.
• It is durable.
• It keeps the body warm.
Natural Materials obtained from animals
Leather
• Leather is obtained from the skin of cattle, snakes, camels and
crocodiles.
Properties of leather
• It is strong.
• It is durable.
• It is flexible.
Natural Materials obtained from the earth
• Metals are materials that are obtained from the earth.
• Iron, aluminium and gold are examples of common metals obtained
from the earth.
Iron
Gold
Aluminium
Gate
Ring
Electricity cables
Magnets
Bracelets
Aeroplane structure
Natural Materials obtained from the earth
Properties of gold
• It is very soft.
• It hardens when other metals are melted with it.
• It does not rust.
Uses of gold
• It is used to make pieces of jewellery.
Natural Materials obtained from the earth
Properties of iron
• It is malleable.
• It is a good conductor of heat and electricity.
• It rusts.
Uses of iron
• It is commonly used in the building industry.
Natural Materials obtained from the earth
Properties of aluminium
• It is hard.
• It is light
• It does not rust.
Uses of aluminium
• It is used to airplanes and utensils.