1)How does the cut on your finger heal ? (1 mark ) 2)Why is Rayon different from synthetic fibres? ( 1 mark )
3)What are synthetic fibres called? (1 mark )
4)Give examples which indicate that nylon fibres are very strong. (1 mark )
5) Explain why plastic containers are favoured for storing food . (3 marks )
6) Explain the difference between thermoplastic and thermosetting plastics. ( 3 marks)
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3) Some fibres are called synthetic because they are not made from natural fibres. Instead, they are made by chemical processing of petrochemicals. The synthetic fibres are made up of very large units called polymers. Some of the synthetic fibres are - nylon, rayon, acrylon

4) is used for making parachutes, rock climbing ropes, fishing nets, seat belts. A nylon thread is actually stronger than steel wire.

5) for the following reasons:

1. Plastic containers do not react with food

2. Plastic containers are light weight so they are easy to handle.

3. The price of plastic containers is very less as compared to other containers.

4. They have strong strength.

5.. Plastic containers are durable

6) (thermosetting plastic)  have primary bonds between molecular chains and held together by strong cross-links

(Thermoplastics)  have secondary bonds between molecular chains

може ли да зареждате повече информация, моля

b) nuclear ive learned that in a pedtrodic table