Class 8 Science Chapter 3 NCERT Solutions – Free PDF Download
One of the most significant topics for students to cover in their exams is Synthetic Fibres and Plastics Chapter 3 of Science Class 8. INFINITY LEARN’s solutions are designed to ensure that students comprehend everything they need to know. They provide clarity in concepts, reasoned explanations, and examples in each response, broadening the scope of comprehension. Synthetic Fibres and Plastics NCERT Solutions Class 8 Science is available for free download in this article. Students looking for NCERT Solutions for Class 8 Science will find the solutions curated by our Master Teachers to be extremely beneficial.
You can also get NCERT Solutions for Class 8 Maths to help you revise the entire syllabus and improve your exam scores.
Synthetic Figres & Plastics
- Explain why some fibres are called synthetic ?
A 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.
- 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.
- b) it is obtained from wood pulp.
- 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 __________ .
- a) man-made, artificial fibres
- b) petrochemicals
- Give examples which indicate that nylon fibres are very strong.
- Nylon is used to make parachutes and ropes of rock climbing, since it is actually stronger than steel wire of same thickness
- Explain why plastic containers are favoured for storing food.
- 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.
- Explain the differences between thermoplastic and thermosetting plastics.
|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
- Explain why the following are made of thermosetting plastic
- a) Saucepan handles
- b) Electric plugs, switches and plug
- 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
- 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.
|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.
- Rana wants to buy shirt for summer. Should he buy cotton shirt (or) Shirt made from synthetic materials? Advice Rana giving your reason.
- 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.
- Give examples to show that plastics are non corrosive.
- 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.
- Should the handle and bristles of a tooth brush be made of the same material? Explain your answer.
- 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.
- “Avoid plastics as far as possible” Comment on this advice.
- 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.
- 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
- i) – d, ii) – c, iii – a, iv – b
- “Manufacturing synthetic fibres is actually helping in conservation of forests”. Comment.
- 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.
- Describe an activity to show that thermoplastic is a poor conductor of electricity.
A. 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
Class 8 Science Chapter 3 NCERT Solutions – Free PDF Download
NCERT answers for Class 8 Science Chapter 3 are quite important in terms of the final test. Students will gain a better understanding of the topic by using the Ncert solutions for Class 8 Science Chapter 3 Synthetic Fibres and Plastics. One of the key goals of this method is to ensure that the concept is clear, that the content is quickly absorbed, and that the language is simple to understand. Understanding the NCERT principles, terminologies, and questioning style are extremely crucial with Ncert solutions for Class 8 Science Chapter 3.
The solutions are created by specialist professional personnel that have a better comprehension of the concepts and the types of replies that must be written in tests, topic by topic. These Ncert Class 8 Chapter 3 Science answers PDF will certainly assist you in your learning and logical thinking.
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NCERT Solutions for Science Chapter 3 – Synthetic Fibres and Plastics in Class
It covers a wide range of topics, including synthetic fiber definitions, types of synthetic fibers, and their characteristics, as well as plastics, benefits of plastics, use of plastic as a choice, environmental hazards of plastic, and exposure to a variety of fibers such as nylon, rayon, melamine, and Bakelite.
The type of cloth we use in our daily lives is the subject of this chapter. Fabric makes up the cloth, hence there are two sorts of fabric discussed in this chapter. The natural fiber that comes from plants and the synthetic fiber that is created by people using chemicals.
There are many different types of synthetic fibers in the environment, each with its own set of traits and benefits. Chapter 3 of Class 8th Science covers the numerous things around us that are made up of various types of synthetic fibers.
To comprehend their implementation in their surroundings, we must first comprehend the essential ideas of these fibers. There’s also a detailed description of plastics, the different types of plastics, the influence of plastic on the environment, and a rational understanding among humans so that it’s easy to decide whether or not to use plastic. Plastics are used in a variety of items around us, and concerns concerning these products and their texture are asked for a good cause.
NCERT Solutions for Class 8 Science Benefits
In INFINITY LEARN’s pdf, every in-text, exemplar, and exercise question is not only answered, but also explained with every reason for students’ greater understanding and reliability. This offline form of study via PDF can also help you keep track of your notes in a logical order, which is essential for getting good grades in tests, so get these pdfs for free right now.
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- There are many different types of synthetic fibers in the environment, each with its own set of traits and benefits. This is Chapter 3 of Science for Class 8th.
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