Q10 of 18 Page 48

Take hair, wool, silk, paper, cotton thread, piece of plastic, thread of sweater, piece of rope and carefully conduct a flame test. Based on smell and type of melting classify them as natural or artificial Fibres.

Natural Fibres give the smell of burning hair upon burning while artificial Fibres upon heating give the smell of the burning paper.


Similarly, Natural Fibres catch fire very early and melt down very easily and artificial Fibres burn slowly.


Depending upon these test, materials can be classified as follows.


Natural Fibres: Hair, wool, silk, cotton thread, the thread of sweater (wool).


Artificial Fibres: paper, a piece of plastic, the thread of sweater (Synthetic) and a piece of rope.


More from this chapter

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8

Fill in the blanks

i) Synthetic Fibres are also called as ______ Fibres.


ii) Synthetic Fibres are synthesized from a raw material called ______


iii) Like synthetic fiber, plastic also ______


iv) Clothing labels are______


a) Required by law


b) Identify fabric content


c) Both a and b


d) None of the above


v) Rayon is made of


a) Coal b) Oxygen c) Flax d) Cellulose


vi) A silk fiber’s smooth surface absorbs light


a) yes b) no c) can’t say

 9

Where do we use the process of recycling? How is it useful? Give examples.

 11

Prepare a table of various synthetic Fibres which are used to make household articles from them?

 12

Explain the differences between the thermoplastics and thermosetting plastics with

the help of a diagram explaining in terms of arrangements of monomers?