Page 36 - Science Class 08

1. What are the synthe c fibres made up of?
2. What is regenerated fibre?

3. Write the proper es of rayon fibres.
4. Why should we not keep rayon clothes in sun for longer period?

5. What is polyester?

6. Write the proper es of polyester.

Synthetic fibres : Man-made fibres

Fibres : Thing used to make clothing fabrics
Natural fibres : Fibres that are obtained from plants and animals
Fabric : A woven material

Incineration : A method of waste disposal by burning
Recycle : To convert waste into reusable material

Polymer : Long chain of molecules containing thousands of smaller molecules
called monomers

Plastic : A material that can be moulded or formed into different shapes

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i Materials that occur in the nature naturally are called natural materials.
i The fabrics made of synthetic fibres can be used not only in making cloth, but also in
making parachutes, matrasses, umbrella, etc.
i Cloth made from synthetic fibre is called synthetic cloth.
i All plastics are synthetic materials made by the chemical industries.
i Plastics are strong, flexible, light, non-reactive and shatterproof. Therefore, plastics are used
for various purposes.
i Recycling is the best way of the disposal of plastic wastes.
i Polyester is also used to make insulating materials that are used to make jackets.

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A. Tick (3) the correct op on.
1. Which of the following is made of synthe c material?
(a) Petrol (b) Paint

(c) Wool (d) Co on

36 Science-8