Exercises
1. Explain why some fibres are called synthetic.
2. Mark the correct answer Rayon is different from synthetic fibres because
(a) it has a silk-like appearance.
(b) it is obtained from wood pulp.
(c) its fibres can also be woven like those of natural fibres.
3. Fill in the blanks with appropriate words.
(a) Synthetic fibres are also called or fibres.
(b) Synthetic fibres are synthesised from raw material called
(c) Like synthetic fibres, plastic is also a
4. Give examples which indicate that nylon fibres are very strong.
5. Explain why plastic containers are favoured for storing food.
Answers
Answer:
1 - Some fibres are made by human beings which are known as synthetic or man-made fibres. These fibres are artificially prepared using various chemicals based on petroleum. Synthetic fibres are made up of small units of substance which combine to form a large single unit called polymer.
2 - (a)
3 - a) artificial fibre
b) petrochemical
c) polymer
4 - The following examples indicate that nylon fibres are very strong : Nylon is used in making parachutes. It is used in making ropes for rock climbing. It is used in making ropes of boats.
5 - Plastic containers are favoured for storing food because plastic is non-reactive and will not react with the ingredients of the food items. Plastic is more easily accessible and is economically friendly to all people. ... Plastic has replaced traditional materials like paperboard, wood, metals.