Synthetic Fibres and Plastics Class 8 Worksheet Science

Q.1. Do all plastics have the same type of arrangement of units?

All plastics do not have the same type of arrangement of units. In some, it is linear, whereas in others it is cross-linked.

Q.2. Give examples that indicate that nylon fibers are very strong.

Nylon fibers are very strong as it is used to make parachutes and ropes for rock climbing.

Q.3. What are the advantages of nylon?

Nylon fiber is strong, elastic, and light. It is lustrous and easy to wash.

Q.4. Which is the first fully synthetic fiber?

Nylon is the first fully synthetic fiber.

Q.5. Why do electrical wires have a plastic covering and handles of screw drivers are made of plastic?

Plastics are poor conductors of heat and electricity. That is why electrical wires have plastic covering, and the handles of screwdrivers are made of plastic.

Q.6. How is the plastic used in the healthcare industry?

Plastics find extensive use in the healthcare industry. Some examples of their use are the packaging of tablets, threads used for stitching wounds, syringes, doctors’ gloves, and a number of medical instruments.

Q.7. What is PET? Write its uses.

PET is a very familiar form of polyester. It is used for making bottles, utensils, films, wires, and many other useful products.

Q.8. Define petrochemicals.

All the synthetic fibers are prepared by a number of processes using raw materials of petroleum origin, called petrochemicals.

Q.9. Explain why some fibers are called synthetic.

Some fibres are called synthetic because they are made by human beings by chemical processing.  Such fibre is made up of small units that join together to form long chains. Each small unit is actually a chemical substance.

Q.10. Why does plastic find such a variety of uses?

The fact is that plastic is easily mouldable i.e. can be shaped in any form. Plastic can be recycled, reused, colored, melted, rolled into sheets, or made into wires. That is why it finds such a variety of uses.

Q.11. Why should we not wear synthetic clothes while working in the kitchen or in a laboratory?

Synthetic fibers melt on heating. If the clothes catch fire, it can be disastrous. The fabric melts and sticks to the body of the person wearing it. We should, therefore, not wear synthetic clothes while working in the kitchen or in a laboratory.

Q.12. “Even though plastics are very useful, they are not environment friendly.” Justify the statement.

Since plastic takes several years to decompose, it is not environmentally friendly. It causes environmental pollution. Besides, the burning process in the synthetic material is quite slow and it does not get completely burnt easily. In the process, it releases lots of poisonous fumes into the atmosphere causing air pollution.

Q.13. ‘Avoid plastics as far as possible. Comment on this advice.

Since plastic takes several years to decompose, it is not environmentally friendly. It causes environmental pollution. Besides, the burning process in the synthetic material is quite slow and it does not get completely burnt easily. In the process, it releases lots of poisonous fumes into the atmosphere causing air pollution. Thus, we should avoid plastic as far as possible.

Q.14. Why we should not throw polybags in the water bodies or on the road?

We should not throw polybags in the water bodies or on the road because
(i) Cow while eating garbage waste food items swallows the polythene bags and wrappers of food. The plastic material chokes the respiratory system of these animals, or forms a lining in their stomachs and can be the cause of their death.
(ii) The polybags are carelessly thrown here and there and are responsible for clogging the drains, too.

Q.15. Why is acrylic fiber more popular than wool?

Acrylic fiber is more popular than wool because
(i) Clothes made from acrylic are relatively cheaper.
(ii) They are available in a variety of colors.
(iii) Synthetic fibers are more durable.