Synthetic Fibres and Plastics
1. Explain why some fibres are called synthetic.
2. Mark ( ) the correct answers.
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 synthesized 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 flavored for storing food.
6. Explain the difference between thermoplastic and thermosetting plastics.
7. Explain why the following are made of thermosetting plastics.
(a) Saucepan handles
(b) Electric plug/ switches /plug boards
8. Categorise the materials of the following products into ‘can be recycled’ and ‘cannot be recycled’.
Telephone instruments, plastic toys, cooker handles, carry bags, ball point pens, plastic bowls, plastic covering on electric wires, plastic chairs, electric switches.
9. Rana wants to buy shirts for summer. Should he buy cotton shirts or shirts made from synthetic material? Advise Rana, giving your reason.
10. Give examples to show that plastics are noncorrosive in nature.
11. Should the handle and bristles of a tooth brush be made of the same material?
Explain your answer.
12. ‘Avoid plastics as far as possible’. Comments on this advise.
13. Match the terms of column A correctly with the phrases given in column B.
(i) Polyester (a) Prepared by using wood pulp.
(ii) Teflon (b) Used for making parachutes and stockings.
(iii) Rayon (c) Used to make non-stick cookware.
(iv) Nylon (d) Fabrics do not wrinkle easily.
14. ‘Manufacturing synthetic fibres is actually helping conservation of forests’. Comment.
15. Describe an activity to show that thermoplastic is a poor conductor or electricity.