Solution of Chapter 3. Synthetic Fibres and Plastics (NCERT - Science Book)

Explain why some fibres are called synthetic.

^{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.

Fill in the blanks with appropriate words.

(a) Synthetic fibres are also called _______or _______ fibres.

(b) Synthetic fibres are synthesised from raw materials called_______.

(c) Like synthetic fibres, plastic is also a________.

Give examples which indicate that nylon fibres are very strong.

Explain why plastic containers are favored for storing food.

Explain the difference between thermoplastic and thermosetting plastics.

Explain why the following are made of thermosetting plastics.

(a) Saucepan handles

(b) Electric plugs/switches/plug boards

Categorize 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, electrical switches.

Rana wants to buy shirts for summer. Should he buy cotton shirts or shirts made from synthetic material? Advise Rana, giving your reason.

Give examples to show that plastics are non-corrosive in nature.

Should the handle and bristles of a tooth brush be made of the same material? Explain your answer.

‘Avoid plastics as far as possible’. Comment on this advice.

Match the terms of column A correctly with the phrases given in column B.

‘Manufacturing synthetic fibres is actually helping conservation of forests’. Comment.

Describe an activity to show that thermoplastic is a poor conductor of electricity.