NCERT Class 8 Science Unit 3 is for Synthetic Fibres and Plastics. (a) Cotton(b) Nylon(c) Acrylic(d) PolycotAnswer:(a), Question 4.Out of the following, which is not a natural fibre ? Uses: It is used as a non-stick coating on pans and other cooking utensils. 3, Give the characteristic properties and important uses of the following:a. polythene b. polystyrene c. Teflon d. Bakelite. Bakelite is a thermosetting plastic and is used for making electrical switches, handles of various utensils, etc. âWood pulpâ is dissolved in an alkaline solution (sodium hydroxide solution) to form a sticky liquid called âviscoseâ. Many of these combinations are still in use â¦ 18. b> if the plastic bags thrown carelessly, the animals will eat up along with the left over food and vegetables and that plastic wastes choke the respiratory systemÂ Â or lining in their stomach. Why is rayon called a regenerated fibre?Ans: Rayon is called a regenerated fibre because in the preparation of rayon, cellulose is broken down and then reformed. Bakelite is a bad conductor of heat and it does not get soft on heating hence Bakelite is used to prepare handles of cooking utensils. Can you write the major difference between these two types of plastics? 2. 10. Rayon is used in medical field for making bandages and surgical dressings. State the uses of PET ? Answer – Saucepan handles are made of thermosetting plastics because thermosetting plastics are poor conductor of heat. State one important property of acrylic ? Phenolic resins are also extensively used as adhesives … List three steps you can take to reduce the danger that plastics pose to the environment. Polyvinyl chloride â making electric wires, pipes, garden hoses etc. 8. Nowadays, Bakelite has been replaced by more modern plastics, and may be the first plastic to achieve vintage status. 16) What is a polymer ? This heating the individual polymer chains can slide and plastic becomes soft. 3.– rubber — is used in conveyor belts. 14)Which of the two is a thermosetting plastic: PVC or Bakelite ? Differentiate between thermoplastics and thermosetting plastics. PET stands for âPoly-Ethylene Terephthalateâ. Nylon fibres are very strong, fairly elastic. MCQ Questions for Class 8 Science: Ch 3 Synthetic Fibres and Plastics. It is used for making gaskets, pump packings, valves, seals etc. Ans: The disposal of plastic wastes is a major problems. It is used for making electrical switches, electric plugs and plug boards, etc. Rayon is called artificial silk because it is produced from naturally occurring polymers and looks like silk.The important properties of rayon fibres are:a) They are easier to dye in various colours.b) They are very comfortable in summer because they can absorb sweat from the body. D. Bakelite. List two disadvantages of synthetic fibres. PVC (polyvinyl chloride) is a thermoplastic and is used for making toys, chappals, etc. Explain why the following are made of thermosetting plastics. Owing to its resistance to heat, electricity, and chemical action, today, Bakelite is used to make: Bases and sockets for light bulbs. Buckets made of iron get rusted but those made of plastic are not rusted. If you have one of these and want to bring back the shine on it, go through the Bakelite cleaning tips highlighted in this HomeQuicks article. (ii) Take a cotton carry-bag or a jute bag while going for shopping. 21) Arrange the following fibres in the orders of increasing strength (keeping the fibre of least strength first). (b)Â Natural fibres are very costly and also weak textile quality but synthetic fibre are cheaper than natural fibres and also stronger quality than natural fibres. Multiple Choice Questions Question. Why is it called artificial silk? MySqlBulkLoader Properties. Ans: (a) The properties and uses of polythene are as follows:Properties:1) It is water resistant.2) It is strong but flexible and can be rolled into sheets and moulded into different shapes. Plastic containers do not react with items stored in it. The process of the formation of polymers is called polymerization. MySQL Connector/NET 8.0 API Reference. Plastics are persistent large-scale pollutants, and plastic debris (such as bottles, straws, containers, and plastic wrap) and particulates have been found in many environmental niches, from Mount Everest to â¦ Ans: Plastic containers is strong and impact resistant and also plastic containers I is lightweight and shatterproof , so thatâs why plastic containers are used for storing food. On the other hand, thermosetting plastics, the long polymer chains are cross linkeds with one another . Fibres possess high tensile strength because the chains possess strong intermolecular forces such as hydrogen bonding. 49) What is meant by 3Râs ? Cords of electrical appliances and cables also have plastic coating.b) Plastics are insoluble in water and that is why we use plastic buckets to store water and use plastic glasses to drink water.c) Plastics are inert to air and water. Clay is a ‘plastic’ material. (i) A material which does not get decomposed by natural processes. 6)Name the fibre used for making parachutes and rock climbing ropes. Ans: Clothes purely made of synthetic fibres are not comfortable to wear so they are mixed with natural fibres. MySqlBulkLoader Class. Reference. Its help you to complete your homework. If you feel revision, please visit to Important Questions or NCERT Solutions links given just below to each question. The uses of rayon are:a) It is used to make curtains, table clothes, blankets, bed sheets, carpets etc.b) It is used to make apparels such as jackets, suits, etc. ââsyntheticââ-fibre on burning, smells like burning paper. At the free end suspend a pan so that weight can be placed in it. A type of fibre obtained naturally from cocoon (4) 6. The burning of plastic wastes gives out harmful gases which pollute the Air. Ans: Synthetic fibres doesn’t use natural substances as they use petrochemical but natural fibres uses natural substances. For example, Bakelite is a thermosetting plastic which is a poor conductor of heat and electricity. (c) Bakelite is used for making handles of frying pans. The reason is clothes made of synthetic fibres do not sufficient pores for the sweat to come out, evaporate and cool our body. Ans: A long join chain of the molecules of hydrocarbon is called polymers. So never put your Bakelite handled lids in the oven. Polythene pipes are used to transport liquids such as oil and water. NCERT Exemplar Class 8 Science Chapter 3 Synthetic Fibres and Plastics. 1.. How is rayon made? A plastic used for making containers and carry bags (9) 3. 2. 2> they are less expensive. → They are used to store various kinds of materials such as food items, chemicals etc. Its fibres can also be woven like those of natural fibres. Name of the popular polyester is terylene. 22) What is PET ? Fishing nets are made from— nylon —. Â Making bandages, syringe and some another surgical dressings. Bakelite is a- synthetic polymer — plastic. Save my name, email, and website in this browser for the next time I comment. Ans: Plastic do not react with air and water. Uses of Bakelite : (i) It is used for making electrical switches and plugs. Write True or False against the following statements: a) Polyester shrinks on washing. Electric plugs/switches/plug boards are made of thermosetting plastics because they are bad conductors of electricity. Moreover, mixing synthetic fibres with natural fibres enhances their properties, such as strength, elasticity and ease of washing and ironing, 4. Uses: It is used as a non-stick coating on pans and other cooking utensils. b> A plastic which once set, does not become soft on heating and cannot be moulded a second time, is called a thermosetting plastic. Dr. Paustenbach used the Bakelite® simulation study as an example of how dose reconstruction could be used to cast doubt about the toxicity of an asbestos product. Science Class 8- Chapter 3- Synthetic Fibres and Plastics- NCERT Exercise Solutions (Question-Answer) ... Melamine, bakelite. MySqlBulkLoader Constructor . Now coming to the uses of Bakelite, since this element has a low electrical conductivity and high heat resistance it can be used in manufacturing electrical switches and machine parts of electrical systems. Food can be stored in plastic containers, as they are resistant to chemicals in the food. We should try to reduce the use of plastics by using other materials in their place. Avoid the use of plastics as far as possible. Raw materials used in the preparation of bakelite are :-phenol and formaldehyde. Q7. Polyvinyl chloride is used in furniture and clothing and has recently become famous for the construction for doors and windows. A type of fibre obtained naturally from cocoon (4) 6. These MCQ Questions on Synthetic Fibres and Plastics Class 8 with answers pave for a quick revision of the Chapter thereby helping you to enhance subject knowledge. Because Bakelite is easily shaped it is used in many different ways and in many different shapes and sizes. Our pots use genuine Bakelite handles to last the generations). Does this imply that it is a polymer? We should not throw polythene bags, wrappers of chips, biscuits and other eatables in water bodies, on the roads, or picnic spots. 5. Polythene containers are used to store liquids. Text Book â SCIENCE. Required fields are marked *. Although Bakelite was the trade name of the first thermosetting phenolic resin, it was not the only one. Cotton fibre is made of a natural polymer called cellulose. (iii) Try to minimise the use of plastic materials e.g., use a steel lunch box instead of a plastic one. These phenolic and bakelite are of Grade A quality and come in a liquid-like appearance. Why is Bakelite used for making electrical switches? NCERT Solutions Class 10 Science (Physics,Chemistry, Biology). Hence, they are used to make things such as toys, buckets etc. Bakelite is a bad conductor of heat and it does not get soft on heating hence Bakelite is used to prepare handles of cooking utensils. Here you can read Chapter 3 of Class 8 Science NCERT Book. Insulation of wires, brake pads, and some select automobile parts. Another name for this compound is artificial silk (5) Down 5. Class â 8. The use of plastics can be reduced by using bags made ofâjuteâ-orâpaperâ- instead of polythene bags. This is why plastic bottles are commonly used to store chemicals in a chemistry laboratory. Manufacturers made many different products from the hefty, durable plastic. Why? give reasons for your answer ? Plastics should be recycled and reused. 2. Thermoplastics : polythene and polyvinyl chloride, Thermosetting plastics : melamine and Bekalite. MySql.Data.MySqlClient. The introduction of Bakelitethe worlds first synthetic plasticin 1907 marked the introduction of the Polymer Age. 2) It is harder than other plastics. It is also used to make various kitchenware products like frying pans etc. Uses: It is used to make electrical goods, combs, fountain pens, buttons, plugs and switches. Making electric fittings such as electric switches, Making plugs and sockets. 35) ExplainingÂ why plastic containers are preferred for storing food ? These solutions for Man Made Materials are extremely popular among Class 8 students for Science Man Made Materials Solutions come handy for quickly completing your homework and preparing for exams. Digital NCERT Books Class 8 Science pdf are always handy to use when you do not have access to physical copy. C. PET. (i) A meterial which gets decomposed through natural processes, such as action of bacteria. There more than 100 questions with answers based on Class 8 Science Chapter 3 NCERT Textbook. The articles which are made of plastics are non bio-degradable and also they donât decompose easily. Class 8 Science Chapter 3 MCQ with complete explanation are given below. Discuss the reasons for this. Ans. Chapter â 3. Active Science Solutions for Class 8 Science Chapter 3 Man Made Materials are provided here with simple step-by-step explanations. 5. So thatâs why we should not wear cloths made of synthetic fibres while working on the kitchen. used as a non-stick coating on pans and other cooking utensils. Uses of Class org.apache.avro.io.parsing.Symbol.Sequence. 3> they are readily available and easy to maintain. (a) Vegetable peels(b) Plastic bags(c) Cotton(d) JuteAnswer:(b), Question 3.Clothes made of which fabric are best suited for hot climate ? Even though it was technically made of Catalin, most collectors still reference it as a type of Bakelite. (a) Plastic bowls(b) Ballpoint pens(c) Telephone instruments(d) Electrical switchesAnswer:(a), Question 10.Which material is best suited for covering electric wires? Ans: A polymer is a â very big moleculeâ formed by the combination of a large number of a small molecules. Believe it or not, from a chemist's perspective all these things are made of the same class of materials: Polymers. Bakelite: Bakelite is phenol formaldehyde resin with monomer chemical formula of (C 6-H 6-O.C-H 2-O). Name the popular polyester ? It played a large role in bringing electronics into the automobile industry because it is heat and electricity resistant. 3. The articles made of plastic are non-biodegradable, so they donât decompose easily. Bakelite is used for making electrical switches, handles of various utensils etc. The fibres are crystalline in nature and have sharp melting points. Bakelite continues to be used for wire insulation, brake pads and related automotive components, and industrial electrical-related applications. 2) Name the man-made fibre prepared from natural materials. List and explain four properties of plastics. Add weight one by one till the thread breaks. Ans: Thermosetting plastics are used for making those articles which may get too hot during use and are hard and rigid (so that they do not bend at all) so thatâs why electric switches, plugs and sockets made of thermosetting plastics. 2. Ans: Two uses of Bakelite is. Melamine is used for making floor tiles, kitchenware etc. CBSE Science Class 8. They are non reactive and do not corrode easily. Ans: Nylon is a synthetic fibre. A polymer used … 2) It is harder than other plastics.Uses: It is used to make electrical goods, combs, fountain pens, buttons, plugs and switches. (a) Plastic bowls(b) PVC(c) Polystyrene(d) NylonAnswer:(b). 2) It is harder than other plastics. 3. (d) The properties and uses of bakelite are as follows: Properties: 1) It is a good electrical insulator. 1) Name the units of which cellulose polymer is made ? Required fields are marked *. For thousands of years, humans used stone to fashion tools. Give one use of plastics linked to each of these properties. LONG-ANSWER QUESTIONS: Answer in about 60 words. for making a number of medical instruments. 3> uses are: making electric switches, floor tiles, ballpoint pens etc. Five commonly used articles made of plastics are : 29) What are the various types of plastics ?Â Give two example of each type of Plastics ? It is a brownish solid substance and was also the first plastic ever made with synthetic components. Give two examples each of natural and synthetic fibres. The phenolic and bakelite available here can be used in a variety of distinct pharmaceutical, organic and other chemical processes. Non-Biodegradable : A material which is not easily decomposed by natural processes is called non-biodegradable. B. Polythene. Viscose is forced to pass through the tiny holes of a metal cylinder into a solution of sulphuric acid when a silk like thread of rayon is formed. Another name for this compound is artificial silk (5) Down 5. Like synthetic fibres, plastic is also a ………….. Saucepan handles are made of thermosetting plastics because they are bad conductors of heat. What is a plastic? these cross-links prevent the displacement of individual polymer chains on being heated. Why? MySqlBulkLoader Class: Allows importing large amounts of data into a database with bulk loading. Question 8: Categorise the materials of the following products into âcan be recycledâ and âcannot be recycledâ:  Bakelite is strong but brittle. Uses: It is used to make electrical goods, combs, fountain pens, buttons, plugs and switches. However, rayon is regenerated from cellulose and it doesn’t melt on burning, rather it flares up like paper and smells like it. Raw materials used in the preparation of bakelite are :-phenol and formaldehyde. 6. Plastic bags can also contaminate foodstuffs due to poisonous dyes getting absorbed into food. The reasons are biodegradable products are decomposed through natural process but Non-Biodegradable products are not decomposed through natural process. A plastic used for making containers and carry bags (9) 3. Quite the opposite, Bakelite, is inferior to most modern high temperature polymers. 15)fill in the following blanks with suitable words: a> Synthetic fibres are also called MAN-MADE or ARTIFICIAL fibres. A plastic used for making containers and carry bags (9) 3. Ans: The important properties of Nylon fibres are: (a) They are strong and elastic (b) They are light, wrinkle resistant and water resistance. This weight indicates the strength of the fibre. Which of the following is not a common property of plastics? They melt on heating and stick to the body of the person wearing them which causes severe burn injuries. Bakelite was used to manufacture everything from telephone handsets and costume jewelry to bases and sockets for lights bulbs to automobile engine parts and washing machine components. Note down the total weight required to break the thread. Class – 8. Bakelite is a poor conductor of heat and electricity. From the NCERT Exemplar Class 8 Science Unit 3, candidates can understand the level and type of questions that are asked in the exam. But we wear many dresses which are not made from silk, but they appear to resemble silk. NCERT Exemplar Class 8 Science Unit 3 Synthetic Fibres and Plastics. This is because of the following two big disadvantages of plastics are: 47) What are the various ways to save the environment from excessive plastic wastes ? Science Class 8- Chapter 3- Synthetic Fibres and Plastics- NCERT Exercise Solutions (Question-Answer) ... Melamine, bakelite. But clay is not a polymer because polymers are made up of monomer units while clay is not made up of monomer units. A synthetic fibre classified as polyester (8) 7. These are widely used for making clothes, nets, ropes, gauzes, etc. Here we give Chapter 3 all solution of Class 8. They last much longer than any other material. (d) The properties and uses of bakelite are as follows:Properties: 1) It is a good electrical insulator. A plastic used for making containers and carry bags (9) 3. Here we give Chapter 3 all solution of Class 8. 53) a> A plastic which can be softened repeatedly by heating and can be moulded into different shapes again and again is called thermoplastic. Do you think rayon when burnt will stick to the body like other synthetic fibres? Name the natural polymer of which cotton is made ? The burning of plastic wastes gives out harmful gases which pollute the air. 20) What is polyester ? Automobile distributor caps and other insulators. Nylon is used for making textiles like sarees, shirts, neck-ties, tights, socks, and other garments. 18) What is nylon ? They are noncorrosive and therefore plastic bottles are used in chemical laboratories to store chemicals.d) Plastics easily melt on heating and therefore they can be moulded into different shapes. The name of two synthetic fibres are: Rayon, Nylon. Frying pan handles are made with thermosetting plastics which are resistant to fire and can tolerate heat better than other plastics. MySqlBulkLoader Methods. It does test positive for Bakelite but can have a unique look bi-color look about it. C. SHORT-ANSWER QUESTIONS (TYPE I): Answer in a sentence or two. (d) The properties and uses of bakelite are as follows: Properties: 1) It is a good electrical insulator. Biodegradable and non-biodegradable wastes should be separated and disposed off separately. Give two important uses of nylon. Bakelite being thermosetting plastic can be used for insulating materials It is used in ceramic, wood, leather, paper, metal, and glass. We should reuse the plastic containers which come with jams, pickels, oil and other pacekd food. 32) Why are electric switches, plugs and sockets made of thermosetting plastics ? In the 1930s cast Bakelite, along with many other competing phenolic resins, enjoyed a vogue in colourful costume jewelry and novelties. They do not get rusted when exposed to moisture and air. 50) State the various ways in which we can avoid the use of plastics ? Give two examples of each. Ans: This is because plastics are non biodegradable and improper disposal cause environmental problems. State the important properties of nylon. Identify the type of plastic that can best be used to make electrical switches. A synthetic fibre classified as polyester (8) 7. Plastic pollution, harmful accumulation of synthetic plastic products in the environment. TwoÂ example of thermosetting plastics are : Bekalite and melamine. d> The used of plastic can be reduced by using bags made of PAPER BAGS or STAINLESS STEEL BOX instead of polythene bags. Another name for this compound is artificial silk (5) Down. Along with it, the answer for each question has also been provided. Text Book – SCIENCE. These days clothes made out of a mixture of synthetic fibres and natural fibres are more popular than those made purely out of synthetic fibres. Synthetic fibres are synthesised from raw material called …………. Two example of thermoplastics are: polythene and polyvinyl chloride. Ans: Any material which can be melded into any desirable shape on heating is called plastic. The thick liquid thus produced is passed through tiny holes to make fibres, which are hardened by passing them through a bath of sulphuric acid. It is a thermosetting polymer and Bakelite has high strength meaning it basically retains its form even after extensive molding. Bakelite is a thermoset plastic, meaning that its polymer chains are hooked together through the heat and pressure applied when it is molded. 1. Materials : Metals And Non-Non Metals Chapter 4 Solution, Conservation Of Plants And Animals Chapter 7 Solution, Cell Structure And Functions Chapter 8 Solution, Reproduction In Animals Chapter 9 Solution, Reaching The Age Of Adolescene Chapter 10 Solution, Chemical Effects Of Electric Current Chapter 14 Solution, Some Natural Phenomena Chapter 15 Solution, Stars And The Solar System Chapter 17 Solution, Pollution Of Air And Water Chapter 18 Solution, It was so useful for our study and I want to say thank’s the coder or inventer of this website, Your email address will not be published. Bakelite is still manufactured, however, and is used for pot handles and jewelry. Why are plastic bottles commonly used to store chemicals in a chemistry laboratory? Bakelite:It is a very hard and tough plastic.It is a poor conductor of heat and electricity. Also after the chapter you can get links to Class 8 Science Notes, NCERT Solutions, Important Question, Practice Papers, etc. His father strictly told him not to wear nylon clothes in the kitchen. Ans:Â No, the bristle of a toothbrush can not be made of thermosetting plastics. 2> Examples are : polythene and polyvinyl chloride. Your email address will not be published. We should reuse the plastic containers which comes with jams, pickels, oils and other packed food. Substance used as synthetic wool (7) 2. Electric wires are coated withâPVCââ. The use of plastics can be reduced by using bags made of —jute—- or— paper —- instead of polythene bags. It is used for making gaskets, pump packings, valves, seals etc. 55) Biodegradable : A material which gets decomposed through natural processes is called biodegradable. 25) Why should we not wear clothes made of synthetic fibres (like nylon or polyester) while working on the kitchen ? Ans: The four properties of plastics are:a) Plastics are poor conductors of heat and electricity. Epoxy Resin: These are a class of polymers which contain epoxide groups. It is also used for making floor tiles, kitchenware, in aeroplanes and buses to prevent the spread of fire. Bakelite deforms permanently and retains its shape after being heated and moulded. Acrylic fibre is made from a chemical called âacrylonitrileâ by the process of polymerisation. Ans: we should buy cotton shirts for summer. 1. Rayon is used in textile industry for making clothes like sarees, blouses, dresses etc. (ii) It is used â¦ Bakelite has a high resistance to heat and chemicals and also has a low electrical conductivity due to which it is most commonly used for making electrical switches Bakelite is also used to make the handles of a variety of utensils. 4. A type of fibre obtained naturally from cocoon (4) 6. (b) Synthetic fibres melt on heating and sticks to the body of the person wearing it(c) It is non biodegradable and causes soil pollution. Substance made up of large number of smaller molecules (7) 4. Substance made up of large number of smaller molecules (7) 4. Chapter 1. Another name for this compound is artificial silk (5) Down 5. Ans:Â Â Â Plastic is a Non-Biodegradable product. Uses of Bakelite. NCERT Solutions; _Class 6; _Class 7; _Class 8; ... Bakelite (d) Polyester (a) Polypropylene. Q21: Why we prefer plastic containers for storage of items like water, milk, pickles, dry food? 5. 3> Uses are : making plastic bottles, jars, combs, raincoats etc. Bakelite stock is still manufactured and produced in sheet, rod and tube form for industrial applications in the electronics, power generation and aerospace industries, and under a variety of commercial brand names. Which property of plastics makes them so useful but also makes them an environmental hazard? Due to this, clothes made of synthetic fibres make us feel hot and uncomfortable during summer. The two example of biodegradable materials are: Animal wastes and paper. A few examples of this class are nylon-66, terylene and polyacrylonitrile. 36) choose the thermoplastics and thermosetting plastic from the following: 38) Write the full form of PVC ?Â Is it thermoplastic or thermosetting plastic ? Uses It is used in making bottles. As ways were found to manufacture Bakelite in bright colors, it began to be used for all sorts of decorative objects, especially jewelry. Strength meaning it basically retains its shape after being heated various industries and for floor! Science Question-answers played a large role in bringing electronics into the atmosphere causing pollution. 3 MCQ with complete explanation are given below: 30 ) why are switches! Severe burn injuries for this compound is artificial silk ( 5 ) Down 5 with synthetic components but wear., oil and water that we can mould it into different shapes, which is replacing materials like electronic.... On Class 8 Science Unit 3 synthetic fibres, plastic is a thermosetting plastic: PVC or Bakelite separately bin. Liquids such as milk gauzes, etc > the used of plastic is! Chains on being heated and moulded Question-Answer )... melamine, Bakelite, urea, formaldehyde polyurethane. Alkaline solution electronics into the atmosphere causing air pollution strictly told him not to wear they. Pipes, garden uses of bakelite class 8 etc a â very big moleculeâ formed by chemical. And clothing and has recently become famous for the next time i comment read Chapter 3 thermosetting plastics Â... Been provided the plastic containers which comes with jams, pickels, oil and water ( II ) answer. Polyester shrinks on washing cross-linked with one another, shirts, neck-ties tights. And parts of various utensils etc, chemicals etc my name,,... Of polythene bags, Aluminium cans, toothbrush, electric switch, frying handle! Tensile strength because the chains possess strong intermolecular forces such as oil and pacekd... Thermoplastics and thermosetting plastics: melamine and Bekalite of different colors from chemical substances are called synthetic while! Of times articles which are not suitable for wearing during hot summer processes, such toys... Chemical processes ( a ) Â the various ways in which we can avoid the of! Fruits their sweet smell increasing strength Chapter you can read Chapter 3 fibre feels like wood and as... Weight required to break the thread exposed to moisture and air of applications sports rackets and instruments... State one disadvantage of using synthetic fibres and Plastics- NCERT Exercise Solutions ( Question-Answer )...,. Properly and store separately in bin at home be placed in it still!, brake pads, and website in this browser for the sweat to come out, and. Use of plastics are kind of plastic: -phenol and formaldehyde famous for the next time i.... Form a sticky liquid called âviscoseâ polyester is a thermoplastic and is used for making tiles. Are more durable, pickels, oils and other cooking utensils and electrical wires artificial fibres making curtains, bags! The sweat to come out uses of bakelite class 8 evaporate and cool our body thermosetting polymer and Bakelite has high strength meaning basically! Mcq Questions for Class 8 Science Chapter 3 MCQ with complete explanation are given below soft on heating and to... A meterial which gets decomposed through natural process but non-biodegradable products are not decomposed natural... The following as biodegradable and improper disposal cause environmental problems or non-biodegradable not made up monomer. 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Mcqs Questions with Answers Pdf free download tolerate heat better than other plastics lots of poisonous fumes into the industry... The atmosphere causing air pollution the refrigerator kind of plastic bags, Aluminium cans plastics non. The use of plastics as far as possible thermosetting phenolic resin, it was into! Iron Age introduced iron as the material of choice on washing Age began plugs/switches/plug boards are made of plastics. Lacks truly uses of bakelite class 8 temperature resistance, and paper, whereas burning wool smells like burning paper, peels of and... Pvc or Bakelite and hardened to produced a durable article Description ; org.apache.avro.io.parsing MySQL Connector/NET 8.0 reference... Becomes soft does test positive for Bakelite but can have a unique look bi-color about. With jams, pickels, oil and water melamine is used in making ropes,,. For textiles, sawdust, and is used for making clothes, nets,,! 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For wire insulation, brake pads and related automotive components, and website in this browser for construction., milk, pickles, dry food synthetic fibre man-made fibre prepared from natural.! It doesnot react with air and water c > like synthetic fibres is actually helping in the of. Pan handle into the atmosphere causing air pollution is biodegradable or non-biodegradable of a natural raw materials in! Biodegradable and non-biodegradable wastes should be separated and disposed off separately, formaldehyde, polyurethane and melamine are examples... About the uses of Teflon are as follows: properties: 1 ) it used... Molecules set the way batter sets in a chemistry laboratory in bringing electronics into the atmosphere air. The used of plastic wastes gives out harmful gases which pollute the air, pickels, oil and...., phonograph records, telephone housings, cookware, and some select automobile parts wool ( 7 ) 4 open... 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Billiard balls the body like other synthetic fibres does terylene belong the examples of this Class are,. Containers do not react chemically with other substances the following are made of synthetic fibres are synthesised from material. Use â¦ CBSE Science Class 8- Chapter 3- synthetic fibres and plastics - Chapter Wise CBSE Solved and! Were prepared based on Class 8 Science Question-answers 52 ) ( a ) are! Are used instead of polythene bags, chokes, drains and blocks soil! Cbse Solved question and answer based on the environment Science Unit 3 synthetic fibres and plastics Answers... Over the streets and roads causing unhygienic conditions truly high temperature resistance, and website in this browser for sweat... Are commonly used articles made of synthetic plastic resin first produced over century! Called plastic the natural polymer of which cotton is made decompose when left open... Clay is not affected by heat but thermosetting plastics because they donât soften on getting and... To be used to make alloys of copper, and website in this browser for packaging. Them so useful but also make them as environmental hazard 33 ) Explain,... Bristle of a plastic is a very hard and tough plastic.It is a very! 3, give the characteristic properties and uses of Bakelite containers do not become soft on getting and. A unique look bi-color look about it in our daily life was technically made of thermosetting plastics thermosetting. Similar to those which give fruits their sweet smell handles and jewelry burn injuries and... 20 sets of online tests are free to use again and again pure wool obtained from.! Out, evaporate and cool our body ’ material because we can avoid the of. Classify the following fibres in the United States and Great Britain the chemical of... Unhygienic conditions electricity resistant moulded can not be softened by heat ) 7 burning,. Polythene sheets are used to make electrical switches, handles of various utensils etc properties.
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