MCQs – Exam Level

Class: 8 | Subject: Science

Chapter 5: Coal and Petroleum

1. Which of the following is a fossil fuel?
   A) Wood
   B) Coal
   C) Biogas
   D) Wind
   Answer: B) Coal

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2. Coal tar is used for making:
   A) Fertilizers
   B) Roads
   C) Glass
   D) Cement
   Answer: B) Roads

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3. Which product of coal is almost pure carbon?
   A) Coal gas
   B) Coke
   C) Coal tar
   D) Charcoal
   Answer: B) Coke

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4. Petroleum is also known as:
   A) Black soil
   B) Brown fuel
   C) Black gold
   D) Liquid coal
   Answer: C) Black gold

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5. The process of separating petroleum into useful products is called:
   A) Distillation
   B) Filtration
   C) Refining
   D) Evaporation
   Answer: C) Refining

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6. Which is the cleanest fossil fuel?
   A) Coal
   B) Petroleum
   C) Diesel
   D) Natural gas
   Answer: D) Natural gas

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7. Which petroleum product is used for surfacing roads?
   A) Petrol
   B) Diesel
   C) Bitumen
   D) Kerosene
   Answer: C) Bitumen

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8. CNG is mainly used as:
   A) Lubricant
   B) Fertilizer
   C) Fuel
   D) Plastic
   Answer: C) Fuel

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9. Fossil fuels are called non-renewable because they:
   A) Are costly
   B) Cause pollution
   C) Take millions of years to form
   D) Are solid fuels
   Answer: C) Take millions of years to form

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10. Which of the following is NOT a petroleum product?
    A) Petrol
    B) Paraffin wax
    C) Coke
    D) Diesel
    Answer: C) Coke

 

One-Page Quick Revision Sheet

Class: 8 | Subject: Science

Chapter 5: Coal and Petroleum

🌍 Fossil Fuels

• Coal, Petroleum, Natural Gas
• Formed from dead plants & animals
• Take millions of years → Non-renewable

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🪨 Coal

• Used as fuel
• Products:
  • Coke – Almost pure carbon (fuel, steel)
  • Coal Tar – Roads, dyes, naphthalene
  • Coal Gas – Fuel

Memory: C³ → Coke | Coal Tar | Coal Gas

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🛢️ Petroleum

• Also called Black Gold
• Found deep inside Earth
• Separated by Refining (Fractional Distillation)

Petroleum Products (Top → Bottom):

Gas → Petrol → Kerosene → Diesel → Lubricating Oil → Paraffin Wax → Bitumen

Memory Sentence:
Good People Keep Doing Lovely Public Business

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🔥 Natural Gas (CNG)

• Cleanest fossil fuel
• High calorific value
• Used in homes & vehicles

Memory: CNG = Clean Natural Gas

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⚠️ Important Exam Points

• Fossil fuels are exhaustible
• Must be conserved
• Excess use causes pollution

VERY IMPORTANT LINE:
“Fossil fuels are non-renewable natural resources formed over millions of years.”

 

Mind Map + Easy Memory Tricks

Class: 8 | Subject: Science

Chapter 5: Coal and Petroleum

🌍 CENTRAL IDEA

Fossil Fuels → Coal | Petroleum | Natural Gas

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🪨 COAL

• Products: Coke, Coal Tar, Coal Gas
• Coke: Pure carbon, fuel, making steel
• Coal Tar: Roads, dyes, naphthalene
• Coal Gas: Fuel

Memory Trick: C³ = Coke – Coal Tar – Coal Gas

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🛢️ PETROLEUM

• Also called Black Gold
• Obtained by Refining
• Separated by Fractional Distillation

Products (Top → Bottom):

• Petroleum Gas (LPG)
• Petrol
• Kerosene
• Diesel
• Lubricating Oil
• Paraffin Wax
• Bitumen

Memory Trick: G P K D L P B
Sentence: Good People Keep Doing Lovely Public Business

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🔥 NATURAL GAS (CNG)

• Cleanest fossil fuel
• High calorific value
• Less pollution

Memory Trick: CNG = Clean – Natural – Gas

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⚠️ IMPORTANT CONCEPT

• Fossil fuels are Non-renewable
• Take millions of years to form
• Limited resources → Must conserve

Exam Line: “Fossil fuels are exhaustible natural resources formed from dead organisms over millions of years.”

 

Important Exam Questions

Class: 8 | Subject: Science

Chapter 5: Coal and Petroleum

Types: VSA / SA / LA

A. Very Short Answer Questions (VSA)

1. What are fossil fuels?
2. Name any one fossil fuel.
3. Which fossil fuel is in gaseous form?
4. Name the purest form of carbon.
5. What is petroleum also called?
6. Name one product obtained from petroleum.
7. Which fuel is considered the cleanest fossil fuel?
8. Where is coal gas obtained from?

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B. Short Answer Questions (SA)

1. Why are fossil fuels called non-renewable resources?
2. What are the main products obtained from coal?
3. State two advantages of CNG.
4. What is coke? Mention one use.
5. What is petroleum refining?
6. Why is petroleum called “black gold”?
7. Write two uses of coal tar.

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C. Long Answer Questions (LA)

1. Explain the formation of fossil fuels.
2. Describe the process of refining petroleum.
3. Explain the various products obtained from coal and their uses.
4. Why should we conserve fossil fuels? Explain.
5. Discuss the advantages of using CNG as a fuel.

 

Worksheet – FULL Answers (Step-by-Step)

Class: 8 | Science

Chapter 5: Coal and Petroleum

A. Very Short Answer Questions (VSA)

1. What are fossil fuels?
   Fossil fuels are fuels formed from the remains of plants and animals buried under the earth for millions of years.
2. Name one solid fossil fuel.
   Coal.
3. What is coke?
   Coke is a tough, porous, black substance and a pure form of carbon.
4. Which fuel is called the cleanest fossil fuel?
   Compressed Natural Gas (CNG).
5. Name one product obtained from petroleum.
   Petrol.

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B. Short Answer Questions (SA)

1. Why are fossil fuels called non-renewable?
   Fossil fuels take millions of years to form and are available in limited quantities. Once used, they cannot be replaced quickly.
2. What are the main products obtained from coal?
   Coke, coal tar, and coal gas.
3. Why is CNG preferred over petrol and diesel?
   CNG produces less pollution, gives more energy, and leaves no residue.
4. What is petroleum refining?
   Petroleum refining is the process of separating crude oil into useful components called fractions.
5. Write two uses of coal tar.
   (i) Making roads
   (ii) Manufacturing dyes and chemicals

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C. Long Answer Questions (LA)

1. Explain the formation of fossil fuels.
   Millions of years ago, plants and animals died and got buried under layers of soil. Due to high pressure and temperature, they slowly converted into coal, petroleum, and natural gas.
2. Describe the process of refining petroleum.
   Crude oil is heated in a refinery. Different fractions separate at different temperatures and are collected separately.
3. Explain the uses of coke, coal tar, and coal gas.
   Coke: Used as fuel and in steel making.
   Coal tar: Used in roads, medicines, dyes.
   Coal gas: Used as fuel.
4. Why should we conserve fossil fuels?
   Fossil fuels are limited and cause pollution. Conserving them helps protect the environment and ensures availability for future generations.

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D. Fill in the Blanks

1. Coal is a solid fossil fuel.
2. Petroleum is also called black gold.
3. CNG gas is used as a fuel in homes and vehicles.
4. Coal tar is used for making roads.

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E. True or False

1. Petroleum is a renewable resource – False
2. Coke is a pure form of carbon – True
3. Natural gas produces less pollution – True
4. Coal gas is obtained during the processing of coal – True

 

Worksheet – Coal and Petroleum

Class: 8 | Chapter: 5

Instructions: Answer all questions. Practice neatly.

A. Very Short Answer Questions (VSA)

1. What are fossil fuels?
2. Name one solid fossil fuel.
3. What is coke?
4. Which fuel is called the cleanest fossil fuel?
5. Name one product obtained from petroleum.

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B. Short Answer Questions (SA)

1. Why are fossil fuels called non-renewable sources of energy?
2. What are the main products obtained from coal?
3. Why is CNG preferred over petrol and diesel?
4. What is petroleum refining?
5. Write two uses of coal tar.

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C. Long Answer Questions (LA)

1. Explain the formation of fossil fuels.
2. Describe the process of refining petroleum.
3. Explain the uses of coke, coal tar, and coal gas.
4. Why should we conserve fossil fuels?

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D. Fill in the Blanks

1. Coal is a ________ fossil fuel.
2. Petroleum is also called ________.
3. ________ gas is used as a fuel in homes and vehicles.
4. Coal tar is used for making ________.

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E. True or False

1. Petroleum is a renewable resource. (True / False)
2. Coke is a pure form of carbon. (True / False)
3. Natural gas produces less pollution. (True / False)
4. Coal gas is obtained during the processing of coal. (True / False)

 

MCQs – Coal and Petroleum (Exam Level)

Class: 8 | Chapter: 5

1. Fossil fuels are formed from the remains of:
   ① Plants only
   ② Animals only
   ③ Plants and animals
   ④ Microorganisms


2. Which of the following is a solid fossil fuel?
   ① Petroleum
   ② Natural gas
   ③ Coal
   ④ CNG


3. Coke is obtained from:
   ① Petroleum
   ② Natural gas
   ③ Coal
   ④ Wood


4. Which fuel is considered the cleanest fossil fuel?
   ① Coal
   ② Petrol
   ③ Diesel
   ④ Natural gas


5. Petroleum is also known as:
   ① Coal oil
   ② Black gold
   ③ White fuel
   ④ Mineral coal


6. The process of separating petroleum into different components is called:
   ① Distillation
   ② Evaporation
   ③ Refining
   ④ Condensation


7. Which product of coal is used in the manufacture of steel?
   ① Coal tar
   ② Coke
   ③ Natural gas
   ④ Petrol


8. CNG stands for:
   ① Compressed Natural Gas
   ② Carbon Natural Gas
   ③ Compressed Nitrogen Gas
   ④ Coal Natural Gas


9. Fossil fuels are called non-renewable because:
   ① They are cheap
   ② They are easily available
   ③ They take millions of years to form
   ④ They are renewable


10. Which of the following is NOT a product of petroleum?
    ① Petrol
    ② Diesel
    ③ Coal tar
    ④ LPG

 

Important Exam Questions – Coal and Petroleum

Class: 8 | Chapter: 5

Very Short Answer Questions (VSA)

1. What are fossil fuels?
2. Name any two fossil fuels.
3. What is coke?
4. Which fuel is known as a clean fuel?
5. Name the natural gas used in homes.
6. What is petroleum also called?
7. What is the main use of coal?
8. Name the solid fossil fuel.

Short Answer Questions (SA)

1. What are fossil fuels? How are they formed?
2. Write any two uses of petroleum.
3. What is natural gas? Write two advantages of natural gas.
4. Explain the process of refining petroleum.
5. Why are fossil fuels called non-renewable resources?
6. Differentiate between renewable and non-renewable resources.

Long Answer Questions (LA)

1. Explain the products obtained from coal and their uses.
2. Describe petroleum refining with the help of a diagram.
3. Why should we conserve fossil fuels? Explain with reasons.
4. Explain the advantages of using natural gas as a fuel.
5. Write a note on alternative fuels and their importance.

 

Conservation of Natural Resources

Conservation of natural resources means using them carefully so that they are available for future generations.

Why Conservation Is Important?

• Natural resources are limited
• They take millions of years to form
• Overuse leads to environmental pollution
• Future generations depend on them

Steps to Conserve Fossil Fuels

• Use public transport
• Switch off vehicles at signals
• Save electricity
• Use energy-efficient appliances

Alternative Fuels

Alternative fuels are sources of energy that can replace fossil fuels and cause less pollution.

Examples of Alternative Fuels

• Solar energy
• Wind energy
• Biogas
• Hydroelectric power

 

Non-Renewable Natural Resources

Non-renewable natural resources are those resources which are present in limited quantity and cannot be replaced once they are exhausted.

Examples of Non-Renewable Resources

• Coal
• Petroleum
• Natural Gas

Why Should We Save Fossil Fuels?

• They take millions of years to form
• They are limited in quantity
• Burning them causes air pollution
• They contribute to global warming

Petrochemicals

Petrochemicals are chemicals obtained from petroleum or natural gas. They are used to manufacture many useful products.

Uses of Petrochemicals

• Making plastics
• Making synthetic fibres
• Making detergents and soaps
• Making medicines and cosmetics

 

Natural Gas

Natural gas is a fossil fuel found deep inside the earth. It is found above petroleum deposits and is the cleanest fossil fuel.

Uses of Natural Gas

• Used as fuel for cooking (PNG and LPG)
• Used in vehicles as CNG
• Used to generate electricity
• Used in industries as fuel

Advantages of Natural Gas

• Burns completely without leaving residue
• Produces very little pollution
• Easy to transport through pipelines

Petroleum Refining

Petroleum refining is the process of separating crude oil into useful components called petroleum products.

Important Petroleum Products

• LPG – Fuel for cooking
• Petrol – Fuel for cars and bikes
• Diesel – Fuel for buses, trucks, and generators
• Kerosene – Fuel for stoves and lamps
• Lubricating Oil – Used in machines
• Bitumen – Used for road surfacing

 

Fossil Fuels

Fossil fuels are fuels formed from the remains of plants and animals that lived millions of years ago. These remains were buried under layers of soil and rocks and slowly changed into fuels due to heat and pressure.

Types of Fossil Fuels

• Coal
• Petroleum
• Natural Gas

Coal

Coal is a hard, black substance found deep under the earth. It is one of the oldest fossil fuels used by humans.

Uses of Coal:

• Used as fuel in thermal power plants to generate electricity
• Used in industries
• Used to make coke, coal tar, and coal gas

Petroleum

Petroleum is a dark, oily liquid found deep inside the earth. It is also known as crude oil.

Petroleum is refined in refineries to obtain useful products like petrol, diesel, kerosene, LPG, and lubricating oil.

 

Class 8 Science – Chapter 5

Coal and Petroleum

🔹 Introduction

Coal and petroleum are very important natural resources. They are used to produce energy, which is required for cooking, transportation, industries, and electricity generation.

🔹 Natural Resources

Natural resources are substances obtained from nature and used by humans for various purposes.

• Exhaustible Natural Resources: Resources that are present in limited quantity and can be exhausted.
  Examples: Coal, Petroleum, Natural Gas
• Inexhaustible Natural Resources: Resources that are available in unlimited quantity.
  Examples: Air, Sunlight, Wind

🔹 Fossil Fuels

Fossil fuels are fuels formed from the remains of dead plants and animals buried under the earth millions of years ago.

Main Fossil Fuels:

• Coal
• Petroleum
• Natural Gas

🔹 Why Fossil Fuels are Limited?

Fossil fuels take millions of years to form. Since they are being used very fast, they may get exhausted in the future. Hence, they are called non-renewable resources.

 

📘 Class 8 Science – Chapter 4
Materials: Metals and Non-Metals

📝 Worksheet (Practice Questions)

Part A: Very Short Answer

1. Name one metal used for making electric wires.
2. Which metal is liquid at room temperature?
3. Name one non-metal used in fertilizers.
4. Which gas is released when metals react with acids?
5. What is the black substance formed on silver?

Part B: Short Answer

1. Write two properties of metals.
2. Why are metals malleable?
3. Write two uses of non-metals.
4. What is corrosion?
5. Why copper is used for making electric wires?

Part C: Long Answer

1. Explain rusting of iron.
2. Write differences between metals and non-metals.
3. Explain methods to prevent rusting.

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✅ FULL ANSWERS (Step-by-Step)

Answers – Part A

1. Copper
2. Mercury
3. Nitrogen
4. Hydrogen gas
5. Silver sulphide

Answers – Part B

1. Two properties of metals:
   • They are good conductors of heat and electricity.
   • They are malleable and ductile.
2. Metals are malleable because metal atoms can slide over each other without breaking.
3. Uses of non-metals:
   • Oxygen is used for breathing.
   • Nitrogen is used in fertilizers.
4. Corrosion is the slow destruction of metals by air, water or chemicals.
5. Copper is used for electric wires because it is a good conductor of electricity and ductile.

Answers – Part C

1. Rusting of Iron:
   Rusting is the process in which iron reacts with oxygen and water to form reddish-brown rust (iron oxide).
   Conditions required: Air and water.
2. Differences between Metals and Non-Metals:
   • Metals are shiny; non-metals are dull.
   • Metals conduct electricity; non-metals do not.
   • Metals are malleable; non-metals are brittle.
3. Methods to Prevent Rusting:
   • Painting
   • Galvanisation
   • Oiling and greasing

CBSE • NCERT • Class 8 Science – Worksheet with Answers

 

📘 Class 8 Science – Chapter 4
Materials: Metals and Non-Metals

⭐ Important Exam Questions (VSA / SA / LA)

🔹 A. Very Short Answer Questions (1 Mark)

1. Name one metal that is liquid at room temperature.
2. Which non-metal is essential for respiration?
3. Write one use of aluminium.
4. What is rust?
5. Which metal is used for electric wires?
6. Name a non-metal used in fertilizers.
7. Which gas is released when metals react with acids?
8. What is corrosion?
9. Name the coating used to prevent rusting.
10. Which non-metal is used in pencil lead?

🔹 B. Short Answer Questions – I (2 Marks)

1. Write any two physical properties of metals.
2. Write two differences between metals and non-metals.
3. Why are metals used for making cooking utensils?
4. What happens when iron reacts with oxygen and water?
5. Name two uses of copper.
6. Why sulphur is a non-metal?
7. What is galvanisation?
8. Why is gold used for making jewellery?

🔹 C. Short Answer Questions – II (3 Marks)

1. Explain corrosion with an example.
2. Write three uses of non-metals.
3. Describe three methods to prevent rusting.
4. Why is aluminium used in aircraft manufacturing?
5. What happens when a metal reacts with an acid? Explain.

🔹 D. Long Answer Questions (5 Marks)

1. Explain physical and chemical properties of metals with examples.
2. Differentiate between metals and non-metals based on:
   • Physical properties
   • Chemical properties
3. Explain rusting of iron:
   • Conditions required
   • Methods to prevent rusting
4. Explain the uses of metals and non-metals in daily life.

🧠 Memory Tip:
Rusting needs both air and water.
Remove any one → No rust.

CBSE • NCERT • Class 8 Science

 

Class 8 Science – Chapter 4
Materials: Metals and Non-Metals
Page 4: Reactions with Acids & Displacement

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1️⃣ Reaction of Metals with Acids

Most metals react with dilute acids to produce salt and hydrogen gas.

Example:

Zinc + Dilute Hydrochloric Acid → Zinc Chloride + Hydrogen

The hydrogen gas produced burns with a ‘pop’ sound.

2️⃣ Reaction of Non-Metals with Acids

Non-metals do not react with dilute acids and hence do not produce hydrogen gas.

3️⃣ Reaction of Metals with Bases

Some metals like zinc and aluminium react with strong bases such as sodium hydroxide.

Example:

Zinc + Sodium Hydroxide → Sodium Zincate + Hydrogen

4️⃣ Displacement Reactions

A more reactive metal can displace a less reactive metal from its compound.

Example:

Iron + Copper Sulphate → Iron Sulphate + Copper

In this reaction, iron displaces copper because iron is more reactive.

⭐ Exam Tip: Displacement reactions depend on the reactivity series of metals.

 

Class 8 Science – Chapter 4
Materials: Metals and Non-Metals
Page 3: Chemical Properties

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1️⃣ Chemical Properties

The properties that describe how a substance reacts with other substances are called chemical properties.

2️⃣ Reaction of Metals with Oxygen

Metals react with oxygen to form metal oxides.

Example:

Magnesium + Oxygen → Magnesium Oxide

Metal oxides are generally basic in nature.

3️⃣ Reaction of Non-Metals with Oxygen

Non-metals react with oxygen to form non-metal oxides.

Example:

Carbon + Oxygen → Carbon Dioxide

Non-metal oxides are generally acidic in nature.

4️⃣ Reaction with Water

• Some metals react vigorously with water (e.g., sodium, potassium).
• Some metals react slowly or not at all.
• Non-metals generally do not react with water.

⚠️ Safety Note: Sodium and potassium are stored in kerosene because they react violently with water.

 

Class 8 Science – Chapter 4
Materials: Metals and Non-Metals
Page 2: Physical Properties

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1️⃣ Physical Properties

The properties of materials that can be observed or measured without changing their chemical nature are called physical properties.

2️⃣ Physical Properties of Metals

• Lustrous: Metals have a shiny surface.
• Hard: Most metals are hard (except sodium and potassium).
• Malleable: Metals can be beaten into thin sheets.
• Ductile: Metals can be drawn into thin wires.
• Good conductors: Metals conduct heat and electricity well.
• Sonorous: Metals produce a ringing sound when struck.

3️⃣ Physical Properties of Non-Metals

• Dull: Most non-metals do not have shine.
• Soft: Many non-metals are soft.
• Brittle: Non-metals break easily when beaten.
• Poor conductors: They do not conduct heat and electricity well.
• Not sonorous: They do not produce sound when struck.

📌 Note: Some non-metals like graphite conduct electricity, and iodine is shiny.

 

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Class 8 Science – Chapter 4
Materials: Metals and Non-Metals
Page 1 – Introduction

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🔹 Introduction

Everything around us is made up of different materials. These materials can be broadly classified into Metals and Non-Metals based on their physical and chemical properties.

🔹 What are Metals?

• Metals are materials that are usually hard, shiny and strong.
• Most metals are solid at room temperature.
• Examples: Iron, Copper, Aluminium, Gold

🔹 What are Non-Metals?

• Non-metals are materials that are generally soft and dull.
• They may exist as solids, liquids or gases.
• Examples: Oxygen, Sulphur, Carbon

🔹 Uses in Daily Life

• Metals are used to make tools, machines, vehicles and wires.
• Non-metals are used in medicines, fertilizers, fuels and breathing.

🔹 Why Study Metals and Non-Metals?

• To understand properties of materials.
• To select proper materials for different uses.
• To learn about natural resources and conservation.

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🌟 Metals give strength, Non-metals give life!

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Class 8 Science – Chapter 3
Synthetic Fibres and Plastics
Final Revision Sheet

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🔹 Key Concepts

• Synthetic fibres are man-made fibres prepared from chemicals.
• Rayon is called artificial silk.
• Nylon was the first fully synthetic fibre.
• Polyester and Acrylic are commonly used synthetic fibres.

🔹 Types of Synthetic Fibres

• Rayon: Made from wood pulp
• Nylon: Strong, elastic, light
• Polyester: Wrinkle resistant
• Acrylic: Artificial wool

🔹 Plastics

• Plastics are polymers.
• They are light, strong, durable and corrosion resistant.
• Non-biodegradable in nature.

🔹 Types of Plastics

• Thermoplastics: Can be bent again (PVC, Polythene)
• Thermosetting Plastics: Cannot be reshaped (Bakelite, Melamine)

🔹 Plastics & Environment

• Plastics cause soil, water and air pollution.
• Burning plastics releases toxic gases.
• Use Reduce, Reuse, Recycle principle.

🔹 Exam Tips

• Learn differences clearly.
• Remember examples of fibres and plastics.
• Environmental questions are important.

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🌱 Revise once before exam = Strong confidence + High marks!

 

Class 8 Science – Chapter 3
Synthetic Fibres and Plastics
Important Exam Questions

---

A. Very Short Answer Questions (1 Mark)

1. What is a synthetic fibre?
2. Name the first synthetic fibre.
3. What is rayon also called?
4. Give one example of thermoplastic.
5. Is plastic biodegradable?

B. Short Answer Questions (2–3 Marks)

1. Why is nylon called a strong fibre?
2. Write any two uses of plastics.
3. Differentiate between natural fibres and synthetic fibres.
4. Why should plastics not be burnt?
5. What are thermosetting plastics? Give one example.

C. Long Answer Questions (5 Marks)

1. Explain the different types of synthetic fibres.
   • Rayon
   • Nylon
   • Polyester
   • Acrylic
2. Explain the properties of plastics that make them useful in daily life.
3. Write advantages and disadvantages of plastics.
4. What are plastics? Explain thermoplastics and thermosetting plastics with examples.

D. Case-Based / Application Questions

A shopkeeper uses plastic bags to pack items for customers.

• Why are plastic bags harmful to the environment?
• Suggest two eco-friendly alternatives.

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⭐ Practice these questions to score full marks in exams.

 

Class 8 Science – Chapter 3
Synthetic Fibres and Plastics
Worksheet – FULL ANSWERS (Step-by-Step)

---

A. Fill in the Blanks – Answers

1. Nylon is the first synthetic fibre.
2. Rayon is also known as artificial silk.
3. Plastics that can be recycled are called thermoplastics.
4. Bakelite is a thermosetting plastic.
5. Plastics do not decompose easily because they are non-biodegradable.

B. True or False – Answers

1. Rayon is obtained from natural sources. (True)
2. All plastics can be recycled. (False)
3. Plastics are poor conductors of heat. (True)
4. Acrylic fibre is used as a substitute for wool. (True)
5. Plastics are biodegradable materials. (False)

C. Very Short Answer – Answers

1. Nylon is one example of a synthetic fibre.
2. Rayon is called artificial silk.
3. Nylon is used to make ropes, parachutes, and clothes.
4. Bakelite is a thermosetting plastic.
5. Plastics are used to cover electric wires because they are poor conductors of electricity.

D. Short Answer – Answers

1. Synthetic fibres are man-made fibres prepared using chemical substances.
2. Thermoplastics can be softened on heating and reused, whereas thermosetting plastics cannot be reshaped once set.
3. Plastic is useful because it is lightweight, strong, durable, and corrosion-resistant.
4. Two disadvantages of plastics are:
   • They cause environmental pollution
   • They are non-biodegradable

E. Long Answer – Step-by-Step

Plastics have several properties that make them useful in daily life:

• They are light in weight
• They are strong and durable
• They do not rust or corrode
• They are poor conductors of heat and electricity
• They can be moulded into different shapes

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✅ Learn answers step-by-step for better exam writing.

 

Class 8 Science – Chapter 3
Synthetic Fibres and Plastics
Worksheet (Practice Questions)

---

A. Fill in the Blanks

1. Nylon is the first __________ fibre.
2. Rayon is also known as __________ silk.
3. Plastics that can be recycled are called __________ plastics.
4. Bakelite is a __________ plastic.
5. Plastics do not decompose easily because they are __________.

B. True or False

1. Rayon is obtained from natural sources. ( )
2. All plastics can be recycled. ( )
3. Plastics are poor conductors of heat. ( )
4. Acrylic fibre is used as a substitute for wool. ( )
5. Plastics are biodegradable materials. ( )

C. Very Short Answer Questions

1. Name one synthetic fibre.
2. Which fibre is called artificial silk?
3. Give one use of nylon.
4. Name one thermosetting plastic.
5. Why are plastics used to cover electric wires?

D. Short Answer Questions

1. What are synthetic fibres?
2. Differentiate between thermoplastic and thermosetting plastic.
3. Why is plastic considered a useful material?
4. Mention two disadvantages of plastics.

E. Long Answer Question

1. Explain the properties of plastics that make them useful in daily life.

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✍️ Practice this worksheet before exams for strong concept clarity.

 

Class 8 Science – Chapter 3
Synthetic Fibres and Plastics
MCQs (Exam Level)

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1. Which of the following is a natural fibre?
   a) Nylon b) Rayon c) Cotton d) Polyester
   Answer: c) Cotton
2. The first fully synthetic fibre is:
   a) Rayon b) Nylon c) Polyester d) Acrylic
   Answer: b) Nylon
3. Which fibre is known as artificial silk?
   a) Nylon b) Polyester c) Rayon d) Acrylic
   Answer: c) Rayon
4. Which plastic cannot be recycled?
   a) Thermoplastic b) Polythene c) PVC d) Thermosetting plastic
   Answer: d) Thermosetting plastic
5. Which of the following is a thermosetting plastic?
   a) PVC b) Bakelite c) Polythene d) Nylon
   Answer: b) Bakelite
6. Why are plastics used to make electrical switches?
   a) They conduct electricity b) They are shiny c) They are poor conductors of electricity d) They melt easily
   Answer: c) They are poor conductors of electricity
7. Which fibre is used to make sweaters?
   a) Nylon b) Rayon c) Acrylic d) Polyester
   Answer: c) Acrylic
8. Plastics are non-biodegradable because:
   a) They dissolve in water b) Microorganisms cannot decompose them c) They are heavy d) They are flexible
   Answer: b) Microorganisms cannot decompose them
9. Which property makes plastics useful for making containers?
   a) Fragile b) Conduct heat c) Lightweight and durable d) Absorb water
   Answer: c) Lightweight and durable
10. Which of the following is correct about plastics?
    a) They are biodegradable b) They catch fire easily c) They are corrosion resistant d) They conduct electricity
    Answer: c) They are corrosion resistant

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⭐ Practice MCQs daily to score full marks in science exams!

 

Class 8 Science – Chapter 3
Synthetic Fibres and Plastics
Important Exam Questions

---

🟠 A. Very Short Answer Questions (1 Mark)

1. What is rayon?
2. Name the first fully synthetic fibre.
3. Which plastic cannot be reshaped once moulded?
4. Name one use of nylon.
5. Is plastic biodegradable?
6. Which fibre resembles wool?

🟠 B. Short Answer Questions (2–3 Marks)

1. Define synthetic fibres. Give two examples.
2. Why is nylon used for making parachutes and ropes?
3. What are thermoplastics? Give two examples.
4. State two disadvantages of plastics.
5. Write any three properties of plastics.

🟠 C. Short Answer Questions (3–4 Marks)

1. Explain the difference between:
   • Natural fibres and synthetic fibres
   • Thermoplastics and thermosetting plastics
2. List four advantages of synthetic fibres.
3. Why are plastics used in electrical appliances?
4. Explain why plastics are non-biodegradable.

🟠 D. Long Answer Questions (5 Marks)

1. What are plastics? Describe their properties and uses.
2. Explain how plastics are harmful to the environment. What steps should we take to reduce plastic pollution?
3. Describe different types of synthetic fibres with their uses.

🟠 E. Case-Based / Application Questions

1. Why should we avoid using plastic bags? Suggest eco-friendly alternatives.
2. Why are handles of cooking utensils made of Bakelite?

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⭐ Focus on definitions, differences & environmental questions for exams!

 

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

---

🟢 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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✅ Practice → Revise → Succeed!

 

Class 8 Science – Chapter 3
Synthetic Fibres and Plastics
Worksheet – Practice Questions

---

🟢 Section A: Fill in the Blanks

1. Rayon is obtained from __________.
2. The first synthetic fibre was __________.
3. Plastics which can be recycled are called __________ plastics.
4. __________ plastic is used to make electrical switches.
5. Acrylic fibre is similar to __________.

🟢 Section B: True or False

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

🟢 Section C: Very Short Answer Questions

1. What is a synthetic fibre?
2. Name any two synthetic fibres.
3. Why is nylon used to make ropes?
4. What is plastic?
5. Name one biodegradable and one non-biodegradable material.

🟢 Section D: Short Answer Questions

1. What are the advantages of synthetic fibres?
2. Differentiate between thermoplastics and thermosetting plastics.
3. Why should plastics not be burnt?
4. Write two uses of Bakelite.

🟢 Section E: Long Answer Question

1. Explain the impact of plastics on the environment. Suggest measures to reduce plastic pollution.

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✍️ Try to answer without looking at notes – self-practice builds confidence!

 

Class 8 Science – Chapter 3
Synthetic Fibres and Plastics
MCQs (Exam Level)

---

1. Rayon is obtained from:
   a) Cotton
   b) Plastic
   c) Wood pulp
   d) Silk
   Answer: c) Wood pulp
2. Which of the following is NOT a synthetic fibre?
   a) Nylon
   b) Rayon
   c) Polyester
   d) Wool
   Answer: d) Wool
3. The first fully synthetic fibre is:
   a) Rayon
   b) Polyester
   c) Nylon
   d) Acrylic
   Answer: c) Nylon
4. Which plastic is used to make electrical switches?
   a) PVC
   b) Polythene
   c) Bakelite
   d) Teflon
   Answer: c) Bakelite
5. Plastics are harmful to the environment because they are:
   a) Biodegradable
   b) Recyclable
   c) Non-biodegradable
   d) Lightweight
   Answer: c) Non-biodegradable
6. Which of the following is a thermosetting plastic?
   a) PVC
   b) Polythene
   c) Bakelite
   d) Nylon
   Answer: c) Bakelite
7. Teflon is commonly used for making:
   a) Bottles
   b) Toys
   c) Non-stick cookware
   d) Bags
   Answer: c) Non-stick cookware
8. Which property makes synthetic fibres suitable for sportswear?
   a) Absorb water easily
   b) Dry quickly
   c) Tear easily
   d) Heavy weight
   Answer: b) Dry quickly
9. Acrylic fibre resembles:
   a) Cotton
   b) Silk
   c) Wool
   d) Jute
   Answer: c) Wool
10. Burning plastics is dangerous because it:
    a) Produces oxygen
    b) Produces toxic gases
    c) Improves air quality
    d) Is eco-friendly
    Answer: b) Produces toxic gases

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⭐ Practice MCQs daily to boost exam confidence

 

Class 8 Science – Chapter 3
Synthetic Fibres and Plastics
Worksheet – FULL Answers (Step-by-Step)

---

🟢 Section A: Very Short Answer – Answers

1. What is rayon?
   Rayon is a synthetic fibre made from natural cellulose obtained from wood pulp.
2. Name one synthetic fibre.
   Nylon.
3. Which plastic is used to make non-stick cookware?
   Teflon.
4. Write one disadvantage of plastics.
   Plastics are non-biodegradable and cause environmental pollution.
5. What does PVC stand for?
   Polyvinyl Chloride.

🟡 Section B: Short Answer – Answers

1. Why is rayon called artificial silk?
   Rayon looks like silk and is shiny like silk, but it is cheaper and made artificially.
2. Write any two properties of synthetic fibres.
   (i) They are strong and durable.
   (ii) They dry quickly and are wrinkle-resistant.
3. Differentiate between thermoplastic and thermosetting plastic.
   Thermoplastics can be softened on heating and reshaped, while thermosetting plastics cannot be reshaped once hardened.
4. Why should plastic not be burnt?
   Burning plastic releases toxic gases that cause air pollution and health problems.
5. Give two uses of nylon.
   (i) Making ropes and parachutes.
   (ii) Making fishing nets.

🔵 Section C: Long Answer – Answers

1. Explain the characteristics of synthetic fibres.
   Synthetic fibres are strong, lightweight, durable, wrinkle-free, and resistant to chemicals. They are easy to maintain.
2. Describe different types of plastics with examples.
   Plastics are of two types: thermoplastics (PVC, polythene) and thermosetting plastics (bakelite, melamine).
3. Explain the harmful effects of plastic on the environment.
   Plastics pollute land and water, harm animals, block drains, and release poisonous gases when burnt.
4. What are the 4R principles?
   Reduce, Reuse, Recycle, and Recover help in controlling plastic pollution.

🟣 Section D: Application Based – Answers

1. Why are plastic containers preferred for storing food?
   They are lightweight, strong, waterproof, and do not react with food.
2. Why are synthetic fibres used to make parachutes and ropes?
   They are very strong, flexible, and can bear heavy loads.

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✅ Practice → Understand → Revise → Score High

 

Class 8 Science – Chapter 3
Synthetic Fibres and Plastics
Worksheet – Practice Questions

---

🟢 Section A: Very Short Answer Questions

1. What is rayon?
2. Name one synthetic fibre.
3. Which plastic is used to make non-stick cookware?
4. Write one disadvantage of plastics.
5. What does PVC stand for?

🟡 Section B: Short Answer Questions

1. Why is rayon called artificial silk?
2. Write any two properties of synthetic fibres.
3. Differentiate between thermoplastic and thermosetting plastic.
4. Why should plastic not be burnt?
5. Give two uses of nylon.

🔵 Section C: Long Answer Questions

1. Explain the characteristics of synthetic fibres.
2. Describe different types of plastics with examples.
3. Explain the harmful effects of plastic on the environment.
4. What are the 4R principles? Explain each.

🟣 Section D: Application Based Questions

1. Why are plastic containers preferred for storing food?
2. Why are synthetic fibres used to make parachutes and ropes?

---

✍️ Attempt all questions neatly in your notebook

 

Class 8 Science – Chapter 3
Synthetic Fibres and Plastics
MCQs (Exam Level)

---

1. Which of the following is a natural fibre?
   a) Nylon
   b) Polyester
   c) Cotton
   d) Acrylic
   Answer: c) Cotton


2. Nylon is synthesised from:
   a) Coal
   b) Petroleum
   c) Wood pulp
   d) Natural gas
   Answer: b) Petroleum


3. Which fibre is also known as artificial silk?
   a) Nylon
   b) Polyester
   c) Rayon
   d) Acrylic
   Answer: c) Rayon


4. Which plastic is used to make electrical switches and handles of utensils?
   a) Polythene
   b) PVC
   c) Bakelite
   d) Melamine
   Answer: c) Bakelite


5. Which of the following plastics cannot be recycled?
   a) Thermoplastic
   b) Polythene
   c) PVC
   d) Thermosetting plastic
   Answer: d) Thermosetting plastic


6. Plastic is harmful for the environment because it is:
   a) Strong
   b) Lightweight
   c) Non-biodegradable
   d) Cheap
   Answer: c) Non-biodegradable


7. Which plastic is commonly used to make kitchenware like plates and bowls?
   a) PVC
   b) Melamine
   c) Bakelite
   d) Teflon
   Answer: b) Melamine


8. Which fibre is used to make sweaters and blankets?
   a) Rayon
   b) Nylon
   c) Polyester
   d) Acrylic
   Answer: d) Acrylic


9. The full form of PVC is:
   a) Poly Vinyl Carbonate
   b) Poly Vinyl Chloride
   c) Poly Vinyl Cellulose
   d) Poly Vinyl Chemical
   Answer: b) Poly Vinyl Chloride


10. Which of the following follows the 4R principle?
    a) Burning plastic waste
    b) Throwing plastic in rivers
    c) Reusing plastic bottles
    d) Burying plastic waste
    Answer: c) Reusing plastic bottles

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✅ These MCQs are useful for school exams, unit tests & competitive exams

 

Class 8 Science – Chapter 3
Synthetic Fibres and Plastics
Important Exam Questions (VSA / SA / LA)

---

🔹 Very Short Answer Questions (1 Mark)

1. Name one synthetic fibre.

Answer: Nylon

2. What is plastic?

Answer: Plastic is a synthetic material made from polymers.

3. Name the plastic used to make electrical switches.

Answer: Bakelite

4. Is plastic biodegradable?

Answer: No

---

🔹 Short Answer Questions (2–3 Marks)

5. What are synthetic fibres? Give two examples.

Answer: Synthetic fibres are man-made fibres prepared using chemicals.
Examples: Nylon and Polyester.

6. Why is nylon called a strong fibre?

Answer: Nylon is strong because it has high tensile strength, is lightweight, durable and resistant to wear and tear.

7. Write two differences between thermoplastic and thermosetting plastic.

Answer:
• Thermoplastics can be reshaped on heating; thermosetting plastics cannot.
• Thermoplastics soften on heating; thermosetting plastics do not.

---

🔹 Long Answer Questions (4–5 Marks)

8. Explain different types of synthetic fibres.

Answer:
• Rayon: Made from wood pulp, looks like silk.
• Nylon: Strong fibre used in ropes and parachutes.
• Polyester: Used in clothes, does not wrinkle easily.
• Acrylic: Used as artificial wool.

9. Why should plastics be avoided? Mention harmful effects.

Answer:
• Plastics are non-biodegradable.
• They cause soil and water pollution.
• Burning plastics releases poisonous gases.
• They harm animals when swallowed.

10. Explain the principle of 4R with respect to plastics.

Answer:
• Reduce: Minimise plastic use.
• Reuse: Use plastic items again.
• Recycle: Convert waste plastic into useful products.
• Recover: Recover energy from plastic waste.

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✅ High-probability exam questions based on CBSE pattern

 

Class 8 Science – Chapter 3
Synthetic Fibres and Plastics
Worksheet – FULL Answers (Step-by-Step)

---

Q1. What are synthetic fibres?

Answer: Synthetic fibres are fibres made by humans using chemical substances. They are not obtained from plants or animals.
Examples: Nylon, Rayon, Polyester, Acrylic.

Q2. Why is rayon called artificial silk?

Answer: Rayon is called artificial silk because it looks like silk and has a shiny appearance like silk, but it is made from wood pulp using chemical treatment.

Q3. Write two uses of nylon.

Answer:
1. Nylon is used to make ropes, parachutes and fishing nets.
2. It is used in making seat belts and toothbrush bristles.

Q4. What is polyester? Write one use.

Answer: Polyester is a synthetic fibre made from chemical substances.
Use: It is used to make clothes, curtains and bedsheets.

Q5. Name two types of plastics.

Answer:
1. Thermoplastics
2. Thermosetting plastics

Q6. What are thermoplastics?

Answer: Thermoplastics are plastics which soften on heating and harden on cooling. They can be moulded again and again.
Examples: Polythene, PVC.

Q7. What are thermosetting plastics?

Answer: Thermosetting plastics are plastics which do not soften when heated once. They cannot be reshaped.
Examples: Bakelite, Melamine.

Q8. Why should plastics be avoided?

Answer: Plastics should be avoided because:
• They are non-biodegradable
• They cause soil and water pollution
• Burning plastics releases toxic gases

Q9. Why is bakelite used for electrical switches?

Answer: Bakelite is a poor conductor of heat and electricity. Therefore, it is safe to use for making electrical switches and plugs.

Q10. Write two advantages of synthetic fibres.

Answer:
1. They are strong and durable.
2. They are lightweight and easy to maintain.

---

🌟 Step-by-step answers help students understand concepts clearly

 

Class 8 Science – Chapter 3
Synthetic Fibres and Plastics
MCQs (Exam Level)

---

1. Synthetic fibres are made from
   A. Natural plants
   B. Animal hair
   C. Chemical substances
   D. Cotton fibres
   Answer: C


2. Which of the following is known as artificial silk?
   A. Nylon
   B. Rayon
   C. Polyester
   D. Acrylic
   Answer: B


3. Which fibre is commonly used to make sweaters and shawls?
   A. Rayon
   B. Nylon
   C. Acrylic
   D. Polyester
   Answer: C


4. The plastic which can be recycled is called
   A. Thermosetting plastic
   B. Bakelite
   C. Melamine
   D. Thermoplastic
   Answer: D


5. Which plastic is used for making electrical switches?
   A. Polythene
   B. PVC
   C. Bakelite
   D. Teflon
   Answer: C


6. Why should plastics not be burnt?
   A. They melt easily
   B. They produce toxic gases
   C. They dissolve in water
   D. They shrink
   Answer: B


7. Which of the following is NOT a property of plastics?
   A. Lightweight
   B. Durable
   C. Biodegradable
   D. Strong
   Answer: C


8. Nylon was first prepared in the year
   A. 1911
   B. 1920
   C. 1931
   D. 1940
   Answer: C


9. Which material is best suited for making parachutes?
   A. Cotton
   B. Wool
   C. Nylon
   D. Silk
   Answer: C


10. Plastics are non-biodegradable because
    A. They are heavy
    B. Microorganisms cannot decompose them
    C. They dissolve in soil
    D. They melt easily
    Answer: B

---

⭐ These MCQs are important for school & competitive exams

 

Class 8 Science – Chapter 3
Synthetic Fibres and Plastics
Important Exam Questions

---

🟢 Very Short Answer Questions (1 Mark)

1. What are synthetic fibres?
2. Name the fibre that looks like silk.
3. Which plastic is used to make electrical switches?
4. Give one example of thermoplastic.
5. From which raw material is nylon made?

🟡 Short Answer Questions (2–3 Marks)

1. Why is rayon called a semi-synthetic fibre?
2. Write any two characteristics of synthetic fibres.
3. Differentiate between thermoplastic and thermosetting plastic.
4. Why should plastics not be burnt?
5. What is meant by biodegradable and non-biodegradable substances?

🔵 Short Answer Questions – Concept Based

1. Why are plastic containers preferred for storing food?
2. Why is nylon used for making parachutes and ropes?
3. Why are synthetic fibres wrinkle-resistant?
4. What happens when plastics are thrown in water bodies?

🟣 Long Answer Questions (4–5 Marks)

1. Explain different types of synthetic fibres with examples.
2. Write advantages and disadvantages of plastics.
3. Explain why plastic is considered a threat to the environment.
4. Describe the properties of plastics that make them useful in daily life.

🔴 Case-Based / HOTS Questions

1. Plastic bags block drains during rains. (a) Why does this happen? (b) Suggest two ways to reduce plastic pollution.
2. A student wants a material that is strong, lightweight, and water-resistant. Which synthetic fibre will you suggest? Give reasons.

---

⭐ These questions are very important for exams – prepare thoroughly

 

Class 8 Science – Chapter 3
Synthetic Fibres and Plastics
Worksheet – FULL Answers (Step-by-Step)

---

🟢 Section A: Very Short Answer – Answers

1. Synthetic fibre: Fibres made by humans using chemical substances are called synthetic fibres.
2. Fibre from wood pulp: Rayon.
3. Artificial silk: Rayon.
4. Thermoplastic example: Polythene.
5. Plastic for switches: Bakelite.

🟡 Section B: Short Answer – Answers

1. Why rayon is semi-synthetic:
   Rayon is made from natural raw material (wood pulp) but processed chemically. Hence, it is called semi-synthetic.
2. Two properties of synthetic fibres:
   (i) They are strong and durable.
   (ii) They are wrinkle-resistant.
3. Difference between natural and synthetic fibres:
   Natural fibres are obtained from plants or animals, while synthetic fibres are made by chemical processes.
4. Why plastics should not be burned:
   Burning plastics releases poisonous gases which pollute air and harm living beings.
5. Biodegradable and non-biodegradable substances:
   Biodegradable substances decompose naturally, whereas non-biodegradable substances do not decompose easily.

🔵 Section C: Fill in the Blanks – Answers

1. Nylon fibre is obtained from petroleum.
2. Plastics are non-biodegradable in nature.
3. Bakelite is a thermosetting plastic.
4. Rayon resembles silk.
5. Plastic bags cause environmental pollution.

🟣 Section D: MCQs – Answers

1. Strongest fibre:
   Answer: (c) Nylon
2. Plastic used for non-stick cookware:
   Answer: (c) Teflon

🔴 Section E: Long Answer – Answers

1. Types of synthetic fibres:
   Rayon, nylon, polyester, and acrylic are common synthetic fibres. They are strong, durable, and easy to maintain.
2. Advantages and disadvantages of plastics:
   Advantages: Lightweight, durable, waterproof.
   Disadvantages: Non-biodegradable and pollute the environment.
3. Why plastic is a threat:
   Plastic does not decompose easily, blocks drains, harms animals, and pollutes land and water.

---

✅ Practice answers carefully for exam success

 

Class 8 Science – Chapter 3
Synthetic Fibres and Plastics
Worksheet – Practice Questions

---

🟢 Section A: Very Short Answer (VSA)

1. What is a synthetic fibre?
2. Name the fibre obtained from wood pulp.
3. Which synthetic fibre is known as artificial silk?
4. Give one example of thermoplastic.
5. Name a plastic used for making electrical switches.

🟡 Section B: Short Answer (SA)

1. Why is rayon called a semi-synthetic fibre?
2. Write any two properties of synthetic fibres.
3. Differentiate between natural fibres and synthetic fibres.
4. Why should plastics not be burned?
5. What are biodegradable and non-biodegradable substances?

🔵 Section C: Fill in the Blanks

1. _________ fibre is obtained from petroleum.
2. Plastics are __________ in nature.
3. Bakelite is a __________ plastic.
4. Rayon resembles __________.
5. Plastic bags cause __________ pollution.

🟣 Section D: Choose the Correct Answer

1. Which fibre is strongest among the following?
   a) Cotton
   b) Wool
   c) Nylon
   d) Silk
2. Which plastic is used to make non-stick cookware?
   a) PVC
   b) Bakelite
   c) Teflon
   d) Polythene

🔴 Section E: Long Answer (LA)

1. Explain the different types of synthetic fibres with examples.
2. Describe the advantages and disadvantages of plastics.
3. Why is plastic considered a threat to the environment?

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✍️ Practice regularly to master this chapter

 

Class 8 Science – Chapter 3
Synthetic Fibres and Plastics
MCQs (Exam Level)

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1. Which of the following is a synthetic fibre?
   a) Cotton
   b) Wool
   c) Nylon
   d) Silk

   Answer: c) Nylon

2. Rayon is obtained from:
   a) Petroleum
   b) Wood pulp
   c) Coal
   d) Cotton seeds

   Answer: b) Wood pulp

3. Which synthetic fibre resembles silk?
   a) Nylon
   b) Polyester
   c) Rayon
   d) Acrylic

   Answer: c) Rayon

4. Which plastic can be softened on heating and reshaped?
   a) Bakelite
   b) Melamine
   c) Thermosetting plastic
   d) Thermoplastic

   Answer: d) Thermoplastic

5. Which of the following is a thermosetting plastic?
   a) PVC
   b) Polythene
   c) Bakelite
   d) Nylon

   Answer: c) Bakelite

6. Plastic is not biodegradable because:
   a) It is soft
   b) It is colourful
   c) Microorganisms cannot decompose it
   d) It dissolves in water

   Answer: c) Microorganisms cannot decompose it

7. Which property makes plastics suitable for storing food?
   a) High conductivity
   b) Reactivity
   c) Non-reactive nature
   d) Transparency

   Answer: c) Non-reactive nature

8. Which plastic is used for making electrical switches?
   a) PVC
   b) Polythene
   c) Bakelite
   d) Polyester

   Answer: c) Bakelite

9. Which fibre is known as artificial wool?
   a) Nylon
   b) Rayon
   c) Acrylic
   d) Polyester

   Answer: c) Acrylic

10. Burning plastics is harmful because:
    a) It releases oxygen
    b) It produces pleasant smell
    c) It releases poisonous gases
    d) It reduces pollution

    Answer: c) It releases poisonous gases

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✅ Practice MCQs = Better Exam Performance

 

Class 8 Science – Chapter 3
Synthetic Fibres and Plastics
Step 5: Biodegradable and Non-Biodegradable Materials

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What are Biodegradable Materials?

Biodegradable materials are substances that can be broken down naturally by microorganisms like bacteria and fungi.

Examples:

• Vegetable waste
• Paper
• Leaves
• Wood
• Cotton cloth

What are Non-Biodegradable Materials?

Non-biodegradable materials do not decompose naturally and remain in the environment for a very long time.

Examples:

• Plastic
• Polythene bags
• Glass
• Metal cans
• Synthetic fibres

Comparison Table

Biodegradable	Non-Biodegradable
Decompose naturally	Do not decompose
Eco-friendly	Cause pollution
Short life in nature	Remain for many years

Why Should We Avoid Non-Biodegradable Waste?

• Pollutes soil, water, and air
• Harms animals and plants
• Clogs drainage systems
• Creates long-term environmental problems

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🌍 Choose Biodegradable – Protect Nature