NCERT 8th Science
Chapter 3
SYNTHETIC FIBRES AND PLASTICS
Exercises
Q. 1 : Explain why some fibres are called synthetic.
Q. 2: Mark (✔) the correct
Q.: 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
Q. 3: Fill in the blanks with appropriate words:
Q. 4: Give examples which indicate that nylon fibres are very strong.
Q. 5: Explain why plastic containers are favoured for storing food.
Q. 6: Explain the difference between the thermoplastic and thermosetting plastics.
Q. 7: Explain why the following are made of thermosetting plastics.
(a) Saucepan handles
(b) Electric plugs/switches/plug boards
Q. 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 electrical wires, plastic chairs and electrical switches.
Q. 9: Rana wants to buy shirts for summer. Should he buy cotton shirts or shirts
made from synthetic material? Advise Rana, giving your reason.
Q. 10: Give examples to show that plastics are noncorrosive in nature.
Q. 11: Should the handle and bristles of a tooth brush be made of the same
material? Explain your Answer
Q. 12: ‘Avoid plastics as far as possible’. Comment on this advice.
Q. 13: Match the terms of column I correctly with the phrases given in column II.
Q. 14: ‘Manufacturing synthetic fibres is actually helping conservation of forests’.
Comment.
Q. 15: Describe an activity to show that thermoplastic is a poor conductor of
electricity.
