Class 8 Science – Chapter 3
Synthetic Fibres and Plastics
Worksheet – FULL Answers

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🟢 Section A: Fill in the Blanks – Answers

1. Rayon is obtained from wood pulp.
2. The first synthetic fibre was nylon.
3. Plastics which can be recycled are called thermoplastics.
4. Bakelite plastic is used to make electrical switches.
5. Acrylic fibre is similar to wool.

🟢 Section B: True or False – Answers

1. Natural fibres are obtained from plants and animals – True
2. Plastics are biodegradable in nature – False
3. Nylon is stronger than silk – True
4. Thermoplastics can be reshaped on heating – True
5. Burning plastics is safe for the environment – False

🟢 Section C: Very Short Answer – Answers

1. What is a synthetic fibre?
   A fibre made by humans using chemical substances is called a synthetic fibre.
2. Name any two synthetic fibres.
   Nylon and polyester.
3. Why is nylon used to make ropes?
   Because nylon is strong, light, elastic and does not break easily.
4. What is plastic?
   Plastic is a synthetic material made from polymers.
5. Name one biodegradable and one non-biodegradable material.
   Biodegradable: cotton
   Non-biodegradable: plastic

🟢 Section D: Short Answer – Answers

1. Advantages of synthetic fibres:
   • Strong and durable
   • Light in weight
   • Easy to wash and dry
   • Wrinkle-free
2. Difference between thermoplastics and thermosetting plastics:
   Thermoplastics can be reshaped on heating, while thermosetting plastics cannot be reshaped once moulded.
3. Why should plastics not be burnt?
   Burning plastics releases poisonous gases that pollute air and harm living beings.
4. Two uses of Bakelite:
   • Electrical switches
   • Handles of cooking utensils

🟢 Section E: Long Answer – Answer

Plastics are harmful to the environment because they are non-biodegradable. They pollute soil and water and harm animals when swallowed. Burning plastics releases toxic gases.

Measures to reduce plastic pollution:
• Reduce the use of plastic
• Reuse plastic items
• Recycle plastics
• Use cloth or jute bags

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