Early Years Science: Materials

The term 'materials' is used to describe all the different things - the 'stuff' - that makes up our world. They include metal, plastic, wood, paper, glass, rock, water, air. Everything, including the clothes we wear and the food we eat, can be described as materials.

Different materials have different properties and behave in different ways - they can be hard, soft, rough, smooth, heavy, light, springy, firm, shiny or dull.

Giving children opportunities to look carefully at different materials, to sort and classify them and to investigate how they behave will help to build their understanding of the world.

What do I need to know?

Below is background knowledge that will help you to:

• support young children's scientific learning

• plan experiences and ask questions that will build children's scientific understanding.

Sorting and classifying materials

Materials can be classified in many different ways, depending on which criteria you choose. Common ways of sorting materials include:

• dividing them into those that normally exist as solids, liquids or gases

• separating them into natural and artificial

• classifying them by their properties and what they are used for.

Solids, liquids and gases

• Everything in the world around us is made of very small units called particles. How these particles are arranged determines whether something is a solid, a liquid or a gas.

• If the particles are held together closely, linked to one another and not able to move apart, the material will be a solid.

• If the particles are further apart so they can move around more, the material will be a liquid.

• If the particles are even more widely spaced and are able to move around freely, the material will be a gas.

• These three different forms of material are known as the states of matter. Some materials are versatile and can exist as solids, liquids or gases. Water is a good example of this. At very low temperatures, below 0xC, water freezes and turns into a solid - ice. Between 0xC and 100xC water exists as a liquid, while above 100xC water turns into a gas - steam.

Natural and man-made materials

'Natural' and 'man-made' seems at first sight to be a simple way to classify materials into two groups: those that occur naturally in the world, and those that have been 'made' by people.

Wood, rock, sand and wool are all examples of natural materials. However, when we experience these materials they have often been changed in some way.

• Tree trunks are cut and sanded and shaped into planks of wood, chairs and tables.

• Rock is cut and shaped into building materials and slate.

• Sand is mixed with stones and cement to form concrete.

• Wool is washed and carded and spun into yarn.

Man-made materials include all the 'stuff' that has been produced by man using a range of naturally occurring resources. The two major groups are:

• plastics which are made from oil. Plastics exist in many different forms and can be hard or soft, transparent or opaque, flexible or rigid.

• metals that are produced by heating and smelting rocks. Some of these, such as gold and silver, are rare and expensive; others, including iron and aluminium, are more common. Many metals are combined together to make alloys such as brass, zinc and stainless steel.

Classifying materials by use

Classifying materials by their properties and how the materials are used is an excellent way to help young children extend their understanding. From your own experience of materials you will be aware that:

• Metals are often hard and feel cold. An object made of metal feels heavy (although aluminium is very light), will conduct electricity and is likely to make a 'metallic' ringing sound if you hit it. Some metals have shiny surfaces which reflect light and act as mirrors.

• Wood is strong and flexible and made of fibres. Objects made of wood usually float in water, can be heavy or light, can be cut with a saw and can be sanded smooth.

• Plastics are light and very long-lasting. They can be bent and stretched, cut and shaped. Plastic objects don't conduct electricity and usually float in water.

• Glass lets light pass through it. Glass breaks easily, and when it is heated it can be blown and moulded into different shapes.

Investigating

Sort it out

What you need:

A selection of objects made of different materials to investigate and sort.

These could include: plastic, wood, metal, paper, cardboard, stone, shells, cones, seeds, leaves, fabric and rubber.

What to do:

• Spend time investigating each object with the children. What does it look like? What does it feel like? Is it rough or smooth, warm or cold? Are there any things you can you see through? Which ones feel heavy? Can you see a reflection of your face in any?

• The next step works well if children team up in pairs. Ask each pair of children to talk about the different objects and sort them into two groups.

• When the investigations and discussions are finished, invite each pair to explain to the rest of the group how they have sorted their objects.

• Listen carefully to what the children say - they will come up with some interesting ideas and reasoning.

• Note down the children's comments and, when all the sorting and classifying is finished, create a display of the children's 'sorting ideas'.

Builders' yard

What you need:

A large plastic tool box containing a selection of building materials and tools that are safe for children to handle. You could include off-cuts of wood, plastic drainpipes, metal brackets, paintbrush, measuring tape, spirit level, hard hat, safely goggles.

What to do:

• Leave the tool box and the building materials in a suitable place outside for the children to find - in a corner or next to the shed is ideal.

• When they discover the box, encourage them to investigate it carefully.

• Discuss all the different tools and materials found. What are they used for? What are they made of? Has anyone seen one of these before? Do you know how to use it? Can you show me?

• Help the children to create a builders' yard and talk about how the different building materials are used.

• Go for a 'building walk' inside and outside the setting and see how many different types of building materials you can spot. What are they made of?

• Encourage the children to use the correct words to describe the materials. These resources can become the focus for an outdoor role-play scenario to add to and develop over time.

Vocabulary to introduce

wood hard natural dull glass soft artificial shiny metal rough solid heavy plastic smooth liquid light

Linda Thornton and Pat Brunton are education consultants with a special interest in science and technology for young children. They can be contacted at www.alcassociates.co.uk.