Table of Contents
In Class 8 Science, Chapter 3 focuses on synthetic fibres and plastics, which are important materials in our everyday lives. This chapter explores what synthetic fibres are, how they are made, and their various uses. It also covers plastics, discussing their properties, types, and the impact they have on the environment. Understanding these materials is essential, as they play a significant role in modern technology and daily living.
As you study this chapter, you will come across various synthetic fibres and plastics class 8 questions and answers that will help reinforce your learning. You can also find helpful resources, such as the synthetic fibres and plastics class 8 PDF, which provides detailed information and illustrations. The NCERT class 8 synthetic fibres and plastics section is designed to align with the CBSE syllabus for class 8, ensuring that you grasp the key concepts effectively.
Additionally, if you’re looking for extra practice, you can refer to the NCERT Solutions for Class 8 science to strengthen your problem-solving skills, which can be beneficial when tackling questions related to this chapter. By understanding synthetic fibres and plastics, you will gain valuable insights into their significance in our lives and the environment.
Synthetic Fibres and Plastics Class 8 Questions Answers PDF
The Synthetic Fibres and Plastics Class 8 Questions Answers PDF is a valuable resource for students studying this important topic. It aligns with the NCERT Class 8 Synthetic Fibres and Plastics chapter, providing clear explanations and answers to help reinforce understanding.
This PDF is designed to meet the CBSE syllabus for Class 8 science, making it an essential tool for exam preparation. Additionally, students can benefit from the structured format and easy access to information, which complements their studies in subjects like NCERT Solutions for Class 8 Science. This resource ensures that learners grasp the concepts of synthetic fibres and plastics effectively.
Synthetic Fibres and Plastics Class 8 Questions Answers
Ques: Explain why some fibres are called synthetic ?
Ans: All fibres are not made from natural sources. Few are produced by using polymers (or) petrochemicals. Hence these fibres which are produced by man made procedures are called synthetic fibres.
Ques: Mark () the correct answer.
Rayon is different from synthetic fibres because
a) it has a silk-like appearance.
b) it is obtained from wood pulp.
c) its fibres can also be woven like those of natural fibres.
Ans: b) it is obtained from wood pulp.
Ques: Fill in the blanks with appropriate words.
a) Synthetic fibres are also called __________ or __________ fibres.
b) Synthetic fibres are synthesised from raw material called __________ .
c) Like synthetic fibres, plastic is also a __________ .
Ans: a) man-made, artificial fibres
b) petrochemicals
c) polymer
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Ques: Give examples which indicate that nylon fibres are very strong.
Ans: Nylon is used to make parachutes and ropes of rock climbing, since it is actually stronger than steel wire of same thickness
Ques: Explain why plastic containers are favoured for storing food.
Ans: Plastics are non corrosive, and are inert to air and water. So food materials, commodities stored in plastic containers remain for long periods as they can be effectively sealed off from contact with air and contaminating agents. Hence they are favoured for storing food materials.
Ques: Explain the differences between thermoplastic and thermosetting plastics.
Ans:
| Thermoplastics | Thermosetting plastic |
| i) Thermoplastics are soft, get easily deformed and melt on heating. | i) They can withstand for heat and electricity. |
| ii) They can be deformed, remoulded | ii) Once they are moulded and shaped they and recycled cannot be melted again,so cannot be recycled. |
| iii) They can be bent with external force | iii) They will break when try to bend with external forces. |
| iv) These are sensitive to high temperatures
Ex : Polyethylene, PVC etc |
iv) These are resistant to high temperatures.
Ex : Bakelite, Melamine |
Ques: Explain why the following are made of thermosetting plastic
a) Saucepan handles
b) Electric plugs, switches and plug
Ans: As we know thermosetting plastics are resistant to high temperature and are poor conductors of electricity Saucepan handles are made from melamine which is resistant to fire and heat. Electrical plugs, switches, and boards are made from bakelite since it is a bad conductor of electricity
Ques: Categorise the materials of the following articles into “can be recycled” and “cannot be recycled” Telephone instruments, plastic toys, cooker handles, carry bags, ball point pens, plastic bowls, plastic covering on electrical wires, plastic chairs, electrical switches.
Ans:
| Can be recycled | Cannot be recycled |
| Plastic toys, carry bags, ball point pens, plastic
plastic covering on electrical wires |
Telephone instruments, cooker handles,
plastic bowls, chairs, electrical switches. |
Ques: Rana wants to buy shirt for summer. Should he buy cotton shirt (or) Shirt made from synthetic materials? Advice Rana giving your reason.
Ans: I Will advice Rana to buy cotton shirt because, cotton is a natural fibre which can act as a good absorbent, light in weight and allows sweat to evaporate easily giving cooling effect.
Ques: Give examples to show that plastics are non corrosive.
Ans: Metals get rusted (or) corroded when exposed to air and water. They also react with chemicals. But most plastics remain uneffected in those cases. Hence they are used in making water bottles, lunch boxes, food storing containers and some kitchen ware.
Ques: Should the handle and bristles of a tooth brush be made of the same material? Explain your answer.
Ans: No, both shouldn’t be made of same material. Because bristles are used to clean our teeth & gum. So it must be type of thermoplastic that is Nylon, which is soft. But handles of tooth brush must be strong and tough. So that it can give some grip and resist our effort on it. So it should be a type of thermosetting plastic.
Ques: “Avoid plastics as far as possible” Comment on this advice.
Ans: Plastics can effect the environmental balance in a wide range. Because plastics are non biodegradable substances and even if we try to burn, complete burning cannot takes place . Plastics can release poisonous gases into atmosphere , up on incomplete burning. Because of above reasons we have to avoid the usage of plastics as far as possible.
Ques: Match the terms of column A correctly with the phrases given in column B.
i) Polyester a) Prepared by using wood pulp
ii) Teflon b) Used for making parachutes and stockings
iii) Rayon c) Used to make non-stick cookwares
iv) Nylon d) Fabrics do not wrinkle easily
Ans: i) – d, ii) – c, iii – a, iv – b
Ques: “Manufacturing synthetic fibres is actually helping in conservation of forests”. Comment.
Ans: Now a days synthetic fibres are being a good source for wide range of articles in our daily need. As natural sources like plant and animal fibres and wood is not available in adequate amounts, the use of synthetic fibres are being a good substitute. Since synthetic fibres are widely used and can be
produced in large quantities, less expensive, we can reduce the usage of Natural sources, like plants and animals for producing fibres. Hence it is very helpful in conservation of forests and wild life.
Ques: Describe an activity to show that thermoplastic is a poor conductor of electricity.
Ans: Make a circuit with bulb, two pieces of electric wire, electric cell , by connecting one end of wires to bulb and other to cell. Now cut the electrical wire at middle and fix an Iron nail in between. Now you can observe that electrical bulb glowing. Then remove Iron nail from circuit, and place a plastic spoon in the circuit. Now observe the bulb, We cannot find any glow of electrical bulb. This proves that plastic is a bad conductor of electricity.
Synthetic Fibres and Plastics NCERT Solutions for Class 8 Science Chapter 3
NCERT Class 8 Science Synthetic Fibres and Plastics – Chapter 3
NCERT Class 8 Science Chapter 3 focuses on Synthetic Fibres and Plastics, which is an important topic for students preparing for their final exams. Understanding this chapter helps students grasp key concepts, making it easier to learn and remember the material. The NCERT solutions for this chapter are designed to clarify these concepts, using simple language that is easy to understand.
These solutions are created by experts who know the subject well and understand what kind of answers are needed in exams. The NCERT Class 8 Chapter 3 Science answers are helpful for improving your learning and logical thinking skills. You can easily download the NCERT solutions in PDF format by clicking the link provided below.
Key Topics Covered –
Chapter 3 covers various important topics, including:
- Definition of Synthetic Fibres: What synthetic fibres are and how they are made.
- Types of Synthetic Fibres: Different types of synthetic fibres like nylon, rayon, melamine, and Bakelite, along with their characteristics and uses.
- Plastics: The benefits of plastics, their applications, and the environmental issues they cause.
This chapter also discusses the types of fabrics we use daily, explaining the difference between natural fibres (which come from plants) and synthetic fibres (which are made by humans using chemicals).
Understanding Synthetic Fibres and Plastics
It is essential to understand the basic ideas of synthetic fibres to see how they are used in our surroundings. The chapter provides detailed information about plastics, including the different types and their impact on the environment. It encourages students to think critically about whether to use plastic products, as plastics are found in many items we encounter every day.
Benefits of NCERT Solutions for Class 8 Science
NCERT solutions provided by INFINITY LEARN include answers to all in-text, exemplar, and exercise questions, along with explanations to help students understand the material better. This PDF format allows for organized note-taking, which is crucial for performing well in exams.
Learning can often be challenging, but INFINITY LEARN makes it enjoyable with engaging 3D graphics that explain concepts clearly. The solutions are updated, precise, and structured to help students learn effectively. They follow CBSE syllabus guidelines and exam patterns closely, ensuring that students are well-prepared.
In summary, Chapter 3 of Class 8 Science offers valuable insights into synthetic fibres and plastics, making it a vital part of your learning journey. Download the NCERT solutions for free now and enhance your understanding of this important topic!
Synthetic Fibres and Plastics Class 8 FAQs
What are synthetic fibres?
Synthetic fibres are man-made fibres produced from chemical substances, usually derived from petroleum. Examples include nylon, polyester, and acrylic. They are designed to mimic natural fibres like cotton and wool but often have additional properties such as strength, durability, and elasticity.
How are synthetic fibres different from natural fibres?
Synthetic fibres are created through chemical processes, whereas natural fibres come from plants or animals. For example, cotton is a natural fibre obtained from the cotton plant, while nylon is a synthetic fibre made from petrochemicals. Synthetic fibres are often more durable and resistant to water and stains than natural fibres.
What are plastics, and how are they related to synthetic fibres?
Plastics are a type of synthetic material made from polymers, which are long chains of molecules. Both plastics and synthetic fibres are made from similar raw materials, often derived from petroleum. While synthetic fibres are used in textiles, plastics are used in a wide range of products, from packaging to household items.
What are the environmental impacts of synthetic fibres and plastics?
Synthetic fibres and plastics can have significant environmental impacts because they are not biodegradable and can persist in the environment for hundreds of years. When disposed of improperly, they contribute to pollution and can harm wildlife. Additionally, the production of synthetic fibres and plastics involves the use of fossil fuels, contributing to greenhouse gas emissions.
