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What is 4R principle?
4R stands for
(i) Reduce : The use of nonbiodegradable materials.
(ii) Reuse : We should use the materials again and again.
(iii) Recycle : We should use the materials which can be recycled.
(iv) Recover : Recover the lacking substances.
Synthetic fibres are synthesised from raw material called ______.
Like synthetic fibres, plastic is also a ________.
Give examples which indicate that nylon fibres are very strong.
Explain why plastic containers are favoured for storing food.
Explain the difference between the thermoplastic and thermosetting plastics.
Explain why the following are made of thermosetting plastics.
(a) Saucepan handles
(b) Electric plugs/switches/plug boards
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,
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 noncorrosive in nature.
Should the handle and bristles of a tooth brush be made of the same material? Explain your answer.
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