Plastics

Question 1 What are plastics?

Question 2 Give few examples of plastics?

Question 3 Give few uses of polythene?

Question 4 Give few use of polyvinyl chloride?

Question 5 Give few uses of bakelite?

Question 6 Give few uses of melamine?

Question 7 Give few uses of teflon?

Question 8 Write 2 characteristics of bakelite?

Question 9 Write 2 characteristics of melamine?

Question 10 Write 1 characteristics of teflon?

• NCERT Solutions Class 8 Science

Plastics

A plastic is a synthetic material which can be moulded or set into desired shape when soft and then hardened to produce a durable article.

Plastics are also polymers.They consist of very long molecules made by joining many small molecules together.

For Ex:Polythene,Polyvinyl chloride,Bakelite,Melamine,teflon etc.

Polythene:It is a plastic obtained by the polymerisation of a chemical compound known as ethene.It is tough and durable.It is used in making polythene bags,waterproof plastic sheets, bottles,buckets,dustbins.

Polyvinyl chloride:It is a strong and hard plastic.It is not as flexible as polythene.It is used for making insulation for electric wires,pipes,garden hoses,raincoats,seat cover etc.

Bakelite:It is a very hard and tough plastic.It is a poor conductor of heat and electricity.

It is used for making the handles of various cooking utensils(fry pans,pressure cooker) because

1)It is a poor conductor of heat

2)It does not become soft on getting heated

It is used for making electric switches,plugs and sockets because

1)It does not conduct electricity

2)It does not become soft on getting heated

Melamine is a plastic which can tolerate heat better than other plastics and resist fire.

It is used for making floor tiles,unbreakable kitchenware,ashtray and fire resistant fabric.

Special plastic cookware made of melamine is used in microwave ovens for cooking food.

Teflon is a special plastic on which oil and water does not stick because it has slippery surface.It can withstand high temperature.

It is used for making soles of electric irons,giving non-stick coating on cookwares.