Question

EXERCISE
A. Multiple Choice Questions
Choose the correct option:
1. Thermocol is a form of
(a) PVC
(b) PET
(c) Polypropylene (d) Polystyrene
2. General property of plastics is/are :
(a) Thermal conductivity
(b) Electrical conductivity
(c) Reactivity
(d) All of these
3. Find the wrong one:
(a) PVC and LDPE are examples of thermoplastics,
(b) Teflon is the brand name of polytetra fluoroethylene
(c) Do not recycle plastic bags
(d) Use separate garbage bins at your home and school for biodegradable and non-
biodegradable wastes
The substance is used in making nonstick utensils of kitchen is:
(a) PVC
(b) Polythene
(c) Teflon (d) Rayon
Which of the following is a group of synthetic fibres?
(a) Nylon, terylene, rayon
(b) Acrylic, silk wool
(c) Cotton, rayon, wool
(d) PVC, polythene, bakelite
B Very Short Answer Type Questions
1. Why do cooking utensils have handles made up of bakelite?
2. It is suggested not to burn plastic and synthetic fibres. Why?
3. What is thermoplastic? Explain with example,
Science-8 (Text Book)​

Answer 1

Answer:

1.(d)

2.(d)

3.(c)

4.(c)

5. (d)

B. very short answer type questions

1.Handles of kitchen utensils are made of bakelite because bakelite is bad conductor of heat, which doesn't let the heat pass through it.

2. Burning of plastics and synthetic fabrics produces lots of poisonous gases causing air pollution. So, it is not advisable to burn plastic and synthetic fibres.

3.Thermoplastics are defined as polymers that can be melted and recast almost indefinitely. They are molten when heated and harden upon cooling. 

examples of thermoplastics are: polypropylene, polystyrene, cellulose acetate, PTFE (Teflon), nylon, polyketone, etc.

Explanation:

HOPE IT HELPS YOU

Answer 2

Answer:

1. d
2. d
3. c
4. c
5. a

Explanation:

This is the correct answer,.,,.,.,.,