Synthetic Fibres and Plastics - Exemplar Solutions 2

CBSE Class 8 Science
NCERT Exemplar Solutions
Synthetic Fibres and Plastic

11. Cotton is a natural polymer. What is its chemical name?
Ans. Cellulose

12. A synthetic fiber which looks like silk is obtained by chemical treatment of wood pulp. It is, therefore, known as artificial silk. What is its common name?
Ans. Rayon

13. Terrycot is made by mixing two types of fibres. Write the names of the fibres.
Ans. Terylene and cotton.

14. Plastic articles are available in all possible shapes and sizes. Can you tell why?
Ans. Plastic is easily mouldable so the articles can be made in any shape and size.

15. Plastic is used for making a large variety of articles of daily use and these articles are very attractive. But it is advised to avoid the use of plastic as far as possible. Why?
Ans. It is advised to avoid the use of plastic as far as possible as  plastis is  non biodegradable material which causes environmental problems and health risks.

16. Why is it not advisable to burn plastic and synthetic fabrics?
Ans. Burning of plastic and synthetic fabrics produces lots of poisonous gases causing air pollution.

17. Select the articles from the following list which are biodegradable.
(a) paper
(b) woolen clothes
(c) wood
(d) aluminium can
(e) plastic bag
(f) peels of vegetables
Ans. Out of the following list: paper, woolen clothes, wood and peels of vegetables are biodegradable.

18. A bucket made of plastic does not rust like a bucket made of iron. Why?
Ans. Plastic is a non-reactive material. It does not react with air and water and thus does not rust.