3.3 To distinguish the most important groups of materials

Natural sciences

The earth and beyond

Properties and uses of materials

Educator section

Memorandum

(There can be many other examples)

Assignment 10:

4 (Individual)

The newspaper and flour are wet with water. Then they are mixed to make a new material, paper maché. Through this process a new mixture / compound is created.

By mixing certain materials we can create new products.

(There can be many other examples)

Assignment 11:

4 (Individual)

(There can be many other examples)

Leaner section

Content

Activity: to distinguish the most important groups of materials [lo 1.2, lo 1.3, lo 3.2]

• Materials can be classified in various ways.
• Let's look at the groups you already know

Mixtures / Compounds

New products are formed when we combine different materials. We can combine water, milk, sugar and coffee powder to make a cup of coffee. We can also combine substances in various ways by mixing them. The appearance and texture of the product usually differs from the original materials. Another example of a mixture is safety glass. A thin plastic layer is sandwiched between two layers of glass.

ASSIGNMENT 10 (INDIVIDUAL)

• To make something by combining substances (materials).

When we combine newspaper, flour and water we get papier-mâché. Make your own dinosaur in the following way.

Requirements:

Water

Flour

Metal wire

Pair of pliers

Newsprint

Paint and brushes

String

Procedure:

• Mix one cup of flour with three cups of water.
• Stir the mixture until it is smooth and creamy.

How to make a wire framework for the dinosaur.

• Bend the wire into the shape of a dinosaur with the pair of pliers.
• Fasten the legs and tail to the body with a piece of string.
• The frame should be able to stand on its own.

Completion:

• Tear the newsprint into long strips.
• Soak the strips in the paste.
• Use the soaked strips to build onto the wire framework.
• Allow the figure to dry.
• Complete the dinosaur by painting it.

Conclusion:

In your own words describe the changes that occurred to the newsprint and the flour.

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Nowadays most clothes are made from a mixture of materials, for example by combining synthetic and natural fibres.

• Natural substances: Wool, cotton, silk, etc.

Cotton is light and comfortable, but it creases easily and is difficult to iron.

• Synthetic substances: are made by humans, for example polyester, acrylic, viscose, glass fibre, etc. One can see these names on the labels of clothes. Have a look at the labels on your clothes.