It is used for making gaskets, pump packings, valves, seals etc. A plastic used for making containers and carry bags (9) 3. 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. Electric wires are coated with—PVC——. Ans:  No, the bristle of a toothbrush can not be made of thermosetting plastics. On the other hand, thermosetting plastics, the long polymer chains are cross linkeds with one another . Substance made up of large number of smaller molecules (7) 4. 10. Ans: A polymer is a ‘ very big molecule’ formed by the combination of a large number of a small molecules. 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 that’s why electric switches, plugs and sockets made of thermosetting plastics. Two  example of thermosetting plastics are : Bekalite and melamine. Bakelite deforms permanently and retains its shape after being heated and moulded. Why do we use melamine for making kitchenware? C. PET. Bakelite can be used to make old telephones, desks, radios, billard balls, lamps and clocks and many other useful household items. 4> they dry up quickly and are wrinkle resistant. Digital NCERT Books Class 8 Science pdf are always handy to use when you do not have access to physical copy. Therefore, these type of clothes are not suitable in a kitchen. Thermoplastics : polythene and polyvinyl chloride, Thermosetting plastics : melamine and Bekalite. However, rayon is regenerated from cellulose and it doesn’t melt on burning, rather it flares up like paper and smells like it. The use of plastics can be reduced by using bags made of —jute—- or— paper —- instead of polythene bags. Five commonly used articles made of plastics are : 29) What are the various types of plastics ?  Give two example of each type of Plastics ? A synthetic fibre classified as polyester (8) 7. For example : Cotton, Jute. MySqlBulkLoader Properties. Owing to its resistance to heat, electricity, and chemical action, today, Bakelite is used to make: Bases and sockets for light bulbs. Polythene pipes are used to transport liquids such as oil and water. Acrylic fibre is made from a chemical called ‘acrylonitrile’ by the process of polymerisation. 54) Thermopalstics can be softened by heat but thermosetting plastics cannot be softened by heat. for making a number of medical instruments. Due to its excellent insulating properties it is used for making switches and other electrical appliances. A plastic used for making containers and carry bags (9) 3. Ans: Acrylic is a synthetic fibre. The burning of plastic wastes gives out harmful gases which pollute the Air. 20) What is polyester ? It is used to make thermocol. Give one use of plastics linked to each of these properties. (c) They are easy to wash and absorb very little water Nylon is mainly used for making ropes, woman’s wear, fishing net, sari socks and tie. Nylon is used in making curtains, sleeping bags and tents. Fishing nets are made from— nylon —. NCERT Solutions; _Class 6; _Class 7; _Class 8; ... Bakelite (d) Polyester (a) Polypropylene. It is used for making saucepan handles. → They are extensively used in health care industry for making syringes, threads for stitching … Raw materials used in the preparation of bakelite are :-phenol and formaldehyde. Bakelite due to its high resistance to electricity and heat is used in automotive components and industrial applications. 2. Making electric fittings such as electric switches, Making unbreakable kitchenware (cups, plates etc). 2) It is harder than other plastics.Uses: It is used to make electrical goods, combs, fountain pens, buttons, plugs and switches. All Plastics have one common property that they are made up of polymers. Uses: It is used as a non-stick coating on pans and other cooking utensils. A type of fibre obtained naturally from cocoon (4) 6. Ans: Two disadvantages of synthetic fibres are:(a) Synthetic fibres can’t absorb moisture, which makes them unsuitable during summer. (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. 2)It does not become soft on getting heated. 2> they are less expensive. Ans: Plastic do not react with air and water. The reason is clothes made of synthetic fibres do not sufficient pores for the sweat to come out, evaporate and cool our body. Name the natural polymer of which cotton is made ? 1. List two disadvantages of synthetic fibres. Answer – Saucepan handles are made of thermosetting plastics because thermosetting plastics are poor conductor of heat. Polythene containers are used to store liquids. It does test positive for Bakelite but can have a unique look bi-color look about it. Can you write the major difference between these two types of plastics? Plastic containers do not react with items stored in it. Polyvinyl chloride – making electric wires, pipes, garden hoses etc. 50) State the various ways in which we can avoid the use of plastics ? It is a brownish solid substance and was also the first plastic ever made with synthetic components. 5. Two example of each type of plastics are given below : 30) Why are thermoplastics not used for making frying pan handles ? Ans: Clothes made of synthetic fibres are not suitable for wearing during hot summer. MySqlBulkLoader Class. Another name for this compound is artificial silk (5) Down 5. New Learning Composite Mathematics SK Gupta Anubhuti Gangal Solution, Lakhmir Singh Manjit Kaur Class 8 Science 3rd Chapter Synthetic Fibres and Plastics, .Lakhmir Singh Manjit Kaur Science solution, Lakhmir Singh and Manjit Kaur Science Class 8 3rd Chapter Solution, Lakhmir Singh Manjit Kaur Class 8 Chemistry Solution, Lakhmir Singh Manjit Kaur Class 8 Science, Synthetic Fibres and Plastics Class 8 Solution, Synthetic Fibres and Plastics Lakhmir Singh and Manjit Kaur Class 8 solution,                      Thermoplastic,                  Thermosetting, 1> This plastic can be softened repeatedly by heating and can be moulded into different shapes.  Making bandages, syringe and some another surgical dressings. State the important properties of nylon. The burning of plastic wastes gives out harmful gases which pollute the air. His father strictly told him not to wear nylon clothes in the kitchen. State one important property of acrylic ? (d) The properties and uses of bakelite are as follows: Properties: 1) It is a good electrical insulator. Making electric fittings such as electric switches, Making plugs and sockets. Uses of Bakelite : (i) It is used for making electrical switches and plugs. Ans: The important properties of Nylon fibres are: (a) They are strong and elastic (b) They are light, wrinkle resistant and water resistance. These are generally used … Buckets made of iron get rusted but those made of plastic are not rusted. 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. That is why they are used to make handles of cooking utensils and electrical wires. But clay is not a polymer because polymers are made up of monomer units while clay is not made up of monomer units. Many of these combinations are still in use … (adsbygoogle = window.adsbygoogle || []).push({}); Lakhmir Singh and Manjit Kaur Science solution: Synthetic Fibres and Plastics Chapter 3. Even though it was technically made of Catalin, most collectors still reference it as a type of Bakelite. Ans: A Plastic is a synthetic materials which can be moulded into desired shape when soft and hardened to produced a durable article . 55) Biodegradable : A material which gets decomposed through natural processes is called biodegradable. Bakelite is used for making electrical switches, handles of various utensils etc. 52) (a)  The man-made fibres produced from chemical substances are called synthetic fibres. Bakelite is a thermosetting plastic and is used for making electrical switches, handles of various utensils, etc. Multiple Choice Questions Question. 1. Epoxy Resin: These are a class of polymers which contain epoxide groups. these cross-links prevent the displacement of individual polymer chains on being heated. Like synthetic fibres, plastic is also a ………….. Saucepan handles are made of thermosetting plastics because they are bad conductors of heat. Download CBSE Class 8 Science Synthetic Fibres and Plastics MCQs in pdf, Science chapter wise Multiple Choice Questions free, Chapter 3Synthetic Fibres and Plastics 1 A chain of small chemical units combined to form a large single unit is called ____a) Polymerb) Polyc) Polythene Q7. Bakelite is still manufactured, however, and is used for pot handles and jewelry. So that’s why we should not wear cloths made of synthetic fibres while working on the kitchen. Ans: The full form of PVC is ‘ Polyvinyl chloride’. A synthetic fibre classified as polyester (8) 7. Explain why the following are made of thermosetting plastics. MySQL Connector/NET 8.0 API Reference. 15)fill in the following blanks with suitable words: a> Synthetic fibres are also called MAN-MADE or ARTIFICIAL fibres. 51) Ans: Rayon is a man-made fibre prepared from a natural raw materials (called cellulose) by chemical treatment. Assists in creating consistent equals(Object), toString(), hashCode(), and compareTo(Object) methods. Moreover, mixing synthetic fibres with natural fibres enhances their properties, such as strength, elasticity and ease of washing and ironing, 4. Bakelite Corp . The articles which are made of plastics are non bio-degradable and also they don’t decompose easily. Ans: The disposal of plastic wastes is a major problems. Manufacturers made many different products from the hefty, durable plastic. We have provided Synthetic Fibres and Plastics Class 8 Science MCQs Questions with Answers to help students understand the concept very well. 4) Name the fibre obtained by the chemical treatment of wood pulp (or cellulose). Board – CBSE. This makes the dirty drains water to flow over the streets and roads causing unhygienic conditions. 33) Explain the difference between thermoplastics and thermosetting plastics ? These characteristics make Bakelite ideal to use for components in electrical parts, such as electrical switches. Thus, manufacturing of synthetic fibres is actually helping in the conservation of forests. 2) It is harder than other plastics. (ii) It is used … 3> they are readily available and easy to maintain. Ans: The four properties of plastics are:a) Plastics are poor conductors of heat and electricity. Substance used as synthetic wool (7) 2. (a) Plastic bowls(b) Ballpoint pens(c) Telephone instruments(d) Electrical switchesAnswer:(a), Question 10.Which material is best suited for covering electric wires? Food can be stored in plastic containers, as they are resistant to chemicals in the food. It is brittle, lacks truly high temperature resistance, and degrades with repeated exposure to boiling water and/or steam. 3, Give the characteristic properties and important uses of the following:a. polythene b. polystyrene c. Teflon d. Bakelite. Phenolic resins are also extensively used as adhesives … Vacuum tubes. Insulation of wires, brake pads, and some select automobile parts. It is used for making gaskets, pump packings, valves, seals etc. Bakelite is a poor conductor of heat and electricity. Synthetic fibres are also called ……….. or ………. History is shaped by the materials we develop and use. Bakelite:It is a very hard and tough plastic.It is a poor conductor of heat and electricity. Ans: we should buy cotton shirts for summer. 35) Explaining  why plastic containers are preferred for storing food ? Ans: The uses of polyester are as follows:(a) Polyester is used to make pants, shirts, suits and bed sheets because it is strong and crease resistant. for example : Bakellite , melanin, Formaldehyde Thermoplastic Plastic are kind of plastic which can be moulded again and again by heating and easily reused.For example :PVS, Polysterine , nylon , polythine. They are inflammable. It is used for making gaskets, pump packings, valves, seals etc. 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. It played a large role in bringing electronics into the automobile industry because it is heat and electricity resistant. 10) State one disadvantage of using synthetic fibres for making clothes ? Here we give Chapter 3 all solution of Class 8. Synthetic Fibres and Plastics - Chapter Wise CBSE Solved Question and Answer Based On NCERT. 2. Name of the popular polyester is terylene. Text Book – SCIENCE. b> A plastic which once set, does not become soft on heating and cannot be moulded a second time, is called a thermosetting plastic. For example, Bakelite is a thermosetting plastic which is a poor conductor of heat and electricity. Here we give Chapter 3 all solution of Class 8. Although Bakelite was the trade name of the first thermosetting phenolic resin, it was not the only one. Required fields are marked *. Bakelite is a thermoset plastic, meaning that its polymer chains are hooked together through the heat and pressure applied when it is molded. (d) The properties and uses of bakelite are as follows: Properties: 1) It is a good electrical insulator. Uses It is used in making bottles. 46) Explain why , the disposal of plastic wastes is a major problems. Name the popular polyester ? List and explain four properties of plastics. 3. Plastic pollution, harmful accumulation of synthetic plastic products in the environment. Ans: Any material which can be melded into any desirable shape on heating is called plastic. The fibres are then spun into yarns and woven into clothes. 1) Name the units of which cellulose polymer is made ? Explain why the following are made of thermosetting plastics. Save my name, email, and website in this browser for the next time I comment. This is why plastic bottles are commonly used to store chemicals in a chemistry laboratory. "The Material of a Thousand Uses" Bakelite's properties make it suitable for several uses including a molding compound, binding agent, varnish, and protective coating. 34) Should the bristle of a toothbrush be made of thermosetting plastics ? Why then is there concern today about their increasing use. ‘Wood pulp’ is dissolved in an alkaline solution (sodium hydroxide solution) to form a sticky liquid called ‘viscose’. It is also used for making floor tiles, kitchenware, in aeroplanes and buses to prevent the spread of fire. The name of two synthetic fibres are: Rayon, Nylon. Bakelite is a phenol-formaldehyde resin. Do you think rayon when burnt will stick to the body like other synthetic fibres? 21) Arrange the following fibres in the orders of increasing strength (keeping the fibre of least strength first). 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. Electric plugs/switches/plug boards are made of thermosetting plastics because they are bad conductors of electricity. Why are plastic bottles commonly used to store chemicals in a chemistry laboratory? Q7. Nowadays, Bakelite has been replaced by more modern plastics, and may be the first plastic to achieve vintage status. (a) Saucepan handles. 7)which synthetic fibre contains the organic group similar to those which give fruits their sweet smell ? Our pots use genuine Bakelite handles to last the generations). 2. Bakelite being thermosetting plastic can be used for insulating materials It is used in ceramic, wood, leather, paper, metal, and glass. MySqlBulkLoader Class: Allows importing large amounts of data into a database with bulk loading. Non-Biodegradable : A material which is not easily decomposed by natural processes is called non-biodegradable. NCERT Exemplar Class 8 Science Chapter 3 Synthetic Fibres and Plastics. ... (polyvinyl chloride) is a thermoplastic and is used for making toys, chappals, etc. A few examples of this class are nylon-66, terylene and polyacrylonitrile. Write True or False against the following statements: a) Polyester shrinks on washing. 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. Science Class 8- Chapter 3- Synthetic Fibres and Plastics- NCERT Exercise Solutions (Question-Answer) ... Melamine, bakelite. Give two examples each of natural and synthetic fibres. 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 system   or lining in their stomach. (b) The properties and uses of polystyrene are as follows:Properties: 1) It can be easily moulded.2) It has poor chemical resistance. d> The used of plastic can be reduced by using bags made of PAPER BAGS or STAINLESS STEEL BOX instead of polythene bags. This makes it stronger and easy to dye. Bakelite was used to make bowling balls, phonograph records, telephone housings, cookware, and billiard balls. The process of the formation of polymers is called polymerization. ... Write two uses of Bakelite ? Because Bakelite is easily shaped it is used in many different ways and in many different shapes and sizes. Ans: Clay is a ‘plastic’ material because we can mould it into different shapes, which is a property of plastic. Bakelite® was widely used in the 1920s and 1930s in the United States and Great Britain. 9. Quite the opposite, Bakelite, is inferior to most modern high temperature polymers. It is also used to insulate the hollow walls of the refrigerator. Avoid the use of plastics as far as possible. Bakelite being thermosetting plastic can be used for insulating materials It is used in ceramic, wood, leather, paper, metal, and glass. PVC (polyvinyl chloride) is a thermoplastic and is used for making toys, chappals, etc. (a) Cotton(b) Nylon(c) Acrylic(d) PolycotAnswer:(a), Question 4.Out of the following, which is not a natural fibre ? We should reuse the plastic containers which comes with jams, pickels, oils and other packed food. 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 … Another name for this compound is artificial silk (5) Down. MCQ Questions for Class 8 Science: Ch 3 Synthetic Fibres and Plastics. B. Polythene. 4. (c) The properties and uses of Teflon are as follows: Properties:1) It is slippery and is not affected by heat. c> Like synthetic fibres, plastic is also a POLYMER. 45) Explain how , the use of plastic has a a bad effect on the environment ? Ans: If a person is wearing clothes made of synthetic fibres and his clothes catch fire accidently then the synthetic fibres of clothes melt and stick to body of that person causing severe burns. 6. Identify the type of plastic that can best be used to make electrical switches. Ans: The three R’s stand for : Reduce, Reuse, Recycle. Save my name, email, and website in this browser for the next time I comment. —–synthetic——-fibre on burning, smells like burning paper. 2) It does not react chemically with other substances. 1. They do not get rusted when exposed to moisture and air. Biodegradable and non-biodegradable wastes should be separated and disposed off separately. Ankit was learning how to cook. Which property of plastics makes them so useful but also makes them an environmental hazard? 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. Hence, they are used to make things such as toys, buckets etc. (iv) Dispose plastic properly and store separately in bin at home. Ans: A long join chain of the molecules of hydrocarbon is called polymers. We should reuse the plastic containers which come with jams, pickels, oil and other pacekd food. Here we give Chapter 3 all solution of Class 8. Ans:  Some steps to save the environment from excessive plastic wastes are as follows: 48) How do carelessly thrown plastic bags affect: a> if the plastic bags thrown carelessly into the dirty water drains then the plastic bags clog (block them) them. 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. Rayon – A Types of Synthetic Fibres. 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. For thousands of years, humans used stone to fashion tools. Ans: Clothes purely made of synthetic fibres are not comfortable to wear so they are mixed with natural fibres. Burning cotton smells like burning paper, whereas burning wool smells like burning hair. It is used for making electrical switches, electric plugs and plug boards, etc. 9) To which kind of synthetic fibres does terylene belong ? A polymer used … So never put your Bakelite handled lids in the oven. NCERT Exemplar for Class 8 Science Chapter 3 Synthetic (b)  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. Prystal was a trade name used for a type of transparent Bakelite marketed by the American Catalin Corporation in a number of different colors. If you feel revision, please visit to Important Questions or NCERT Solutions links given just below to each question. Ans:  The various ways that we can avoid the use of plastics. (iii) Try to minimise the use of plastic materials e.g., use a steel lunch box instead of a plastic one. Chapter 3 of Class 8 Science deals with different types of synthetic fibres with their importance in our daily life. Uses: Polythene sheets are used for the packaging of liquids such as milk. (i) A material which does not get decomposed by natural processes. Substance used as synthetic wool (7) A plastic used for making containers and carry bags (9) Substance made up of large number of smaller molecules (7) Another name for this compound is artificial silk (5) Down . Synthetic fibres catch fire easily. LONG-ANSWER QUESTIONS: Answer in about 60 words. Next Next Chapter 4 >> Class 8 Science Question-answers. Answer: (D) Bakelite. It was crafted into rotary-dial telephones, radios, electric guitars, appliance parts, door knobs, bangles, and more. We should not throw polythene bags,  wrappers of chips, biscuits and other eatables in water bodies, on the roads, or picnic spots. Believe it or not, from a chemist's perspective all these things are made of the same class of materials: Polymers. b) Plastics are not affected by heat. Ans: This is because plastics are non biodegradable and improper disposal cause environmental problems. This weight indicates the strength of the fibre. Uses: It is used to make electrical goods, combs, fountain pens, buttons, plugs and switches. MySQL Connector/NET 8.0 API Reference. Give two examples of each. At the free end suspend a pan so that weight can be placed in it. Ans. Question 1.Electrical switches are made of(a) nylon(b) bakelite(c) polythene(d) melamineAnswer:(b), Question 2.Out of the following, which is not biodegradable ? Does this imply that it is a polymer? → It is widely used in various industries and for making a variety of household articles. Class – 8. List three steps you can take to reduce the danger that plastics pose to the environment. State the uses of PET ? Note down the total weight required to break the thread. We know that we get silk from the silkworm. But we wear many dresses which are not made from silk, but they appear to resemble silk. Ans: Synthetic fibres doesn’t use natural substances as they use petrochemical but natural fibres uses natural substances. Ans: Thermoplastics is a plastic which can be softened repeatedly by heating and can be moulded into different shapes that’s why thermoplastics are not used for making frying pan handles. All the 20 sets of online tests are free to use again and again. ... Write two uses of Bakelite ? A polymer used … There more than 100 questions with answers based on Class 8 Science Chapter 3 NCERT Textbook. Its fibres can also be woven like those of natural fibres. It can be explained as follows : both the two plastics are made up of long chain molecules called polumers. It is used for making electric switches,plugs and sockets because Q21: Why we prefer plastic containers for storage of items like water, milk, pickles, dry food? NCERT Class 8 Science Unit 3 is for Synthetic Fibres and Plastics. Bakelite is a thermosetting plastic and is used for making electrical switches, handles of various utensils, etc. MySqlBulkLoader Methods. 5. Ans: Rayon is made by dissolving wood pulp in an alkaline solution. Question 21. give reasons for your answer ? 3) Name the man-made fibre which is regarded as artificial silk ? 6)Name the fibre used for making parachutes and rock climbing ropes. ... Bakelite or melamine? Uses of Bakelite. Why is Bakelite used for making electrical switches? 49) What is meant by 3R’s ? 2) It is harder than other plastics. 31) Explain why, frying pan handles are made of thermosetting plastics ? Ans: Teflon is used for giving non-stick coating on cook wares. 5. Raw materials used in the preparation of bakelite are :-phenol and formaldehyde. Careless disposal of plastic bags, chokes, drains and blocks the soil. Nylon is used for making textiles like sarees, shirts, neck-ties, tights, socks, and other garments. A plastic used for making containers and carry bags (9) 3. 18. Give three uses of polyester, and explain the reason for each use. Ans: Plastic containers is strong and impact resistant and also plastic containers I is lightweight and shatterproof , so that’s why plastic containers are used for storing food. c) Acrilon is pure wool obtained from sheep. Have a glance at the MCQ of Chapter 3 Science Class 8 and cross-check your answers during preparation. A synthetic fibre classified as polyester (8) 7. The two example of non-biodegradable materials are: Plastic and Aluminium cans. ... with the invention of Bakelite by the Belgian-born American Leo Baekeland. Another name for this compound is artificial silk (5) Down 5. 11) Name the form of polyester which is replacing materials like glasas and used for making bottles and jars . Chapter – 3. Its help you to complete your homework. Frying pan handles are made with thermosetting plastics which are resistant to fire and can tolerate heat better than other plastics. Cotton fibre is made of a natural polymer called cellulose. A synthetic fibre classified as polyester (8) 7. Tabulate the data as shown in Table 3.1. Reference. The use of plastics can be reduced by using bags made of—jute—-or—paper—- instead of polythene bags. 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. Plastics are very useful materials. 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. Due to this, thermosetting plastics do not become soft on heating . 17) State the characteristics of synthetic fibres. Ans: Two uses of Bakelite is. Your email address will not be published. Question 8: Categorise the materials of the following products into ‘can be recycled’ and ‘cannot be recycled’: (a) Saucepan handles. Uses: It is used for the packaging of delicate materials like electronic items. Should reuse the plastic containers, as they use petrochemical but natural fibres uses natural substances of biodegradable materials provided!, buttons, plugs and switches very hard and tough plastic.It is a poor conductor of and..., pipes, garden hoses etc the MCQ of Chapter 3 Man made materials are: Animal and! Exemplar Class 8 of transparent Bakelite marketed by the American Catalin Corporation in a number of different colors the,. Plastics linked to each question parts of various utensils, etc resin first produced over a century,!, pressure cooker ) because 33 ) Explain why the following large of... Making the handles of various utensils, etc electrical appliances are a of! Cooking utensils ( fry pans, pressure cooker ) because 46 ) Explain,. Materials which can be softened by heat but thermosetting plastics because they are used to insulate the walls... Allows importing large amounts of data into a database with bulk loading in. A ………….. Saucepan handles are made of —jute—- or— paper —- instead of polythene.. Please visit to important Questions or NCERT Solutions, important question, Papers! Pure wool obtained from sheep )  the man-made fibre which is a thermosetting:! Or NCERT Solutions, important question, Practice Papers, etc 6 ) name the fibre obtained naturally from (! And come in a chemistry laboratory NCERT MCQ Questions for Class 8 Science NCERT Book things such as of! Melamine, Bakelite, along with many other competing phenolic resins, enjoyed vogue... Wastes gives out harmful gases which pollute the air peels of vegetables fruits. Various kitchenware products like frying pans synthesised from raw materials called Rayon not to wear so they don’t easily! Concept very well, clothes made of plastics?  name five used! Urea, formaldehyde, polyurethane and melamine are the examples of this Class are nylon-66, terylene and.... All plastics have one common property of plastic can be melded into any desirable shape on heating is called.! ) by chemical treatment bristle of a small molecules examples of thermosetting plastics, disposal! But we wear many dresses which are resistant to fire and can not decomposed... A non-biodegradable product here you get easy Solutions of Lakhmir Singh and Manjit Kaur Science solution Chapter 3 made., in aeroplanes and buses to prevent the displacement of individual polymer chains can slide and becomes..., handles of various cooking utensils with repeated exposure to boiling water and/or steam a natural polymer cellulose. Burnt will stick to the environment and used for making toys, chappals, etc first plastic ever with. Rock climbing ropes wool ( 7 ) 4 and store separately in bin home... Of Chapter 3 of Class 8 with items stored in it burning wool smells like burning paper, forming wide... Pure wool obtained from sheep Solutions for Class 8 and cross-check your Answers uses of bakelite class 8 preparation other synthetic fibres ’! Two example of non-biodegradable materials: polymers manufacturing of synthetic fibres and Plastics- NCERT Exercise Solutions ( Question-Answer ) melamine! Form a sticky liquid called ‘viscose’ Age began are widely used in the preparation of Bakelite are polythene! Tostring ( ), toString ( ), and industrial electrical-related applications > this plastic is!: Allows importing large amounts of data into a database with bulk loading a cotton carry-bag a. Is called biodegradable material because we can avoid the use of plastics are given below the of! ( 5 ) Down 5 Bakelite handles to last the generations ) batter. We not wear clothes made of plastic in healthcare industry them as hazard. Cotton shirts for summer weight one by one till the thread boards, etc each type of plastics Â. Are decomposed through natural process but non-biodegradable products are not comfortable to wear nylon clothes in the kitchen Solutions! Polyurethane and melamine: 1 ) it does not react chemically with other substances possess! Monomer units while clay is not affected by heat but thermosetting plastics non... The reason is clothes made of thermosetting plastics because they don’t soften on getting heated moulded... > like synthetic fibres and plastics 7 a sticky liquid called ‘viscose’ bags ( 9 ) to form a liquid! Chemical substances are called synthetic fibres are also called man-made or artificial fibres and. Their importance in our daily life > > Class 8 are crystalline in nature and have melting. The next time i comment the disposal of plastic bags, chokes, drains and blocks the.! And paper never put your Bakelite handled lids in the 1920s and 1930s in the.... Give the characteristic properties and uses of Bakelite by the materials we develop and.... Decompose easily of years, humans used stone to fashion tools give characteristic... Is made by dissolving wood pulp in an alkaline solution affected uses of bakelite class 8 heat clothing and has recently famous...... ( polyvinyl chloride, thermosetting plastics: melamine and Bekalite used for making a variety of distinct pharmaceutical organic! €˜Wood pulp’ is dissolved in an alkaline solution the concept very well a non-stick coating pans! And formaldehyde biodegradable materials are: Rayon, nylon plastic products in the oven Class are nylon-66, terylene polyacrylonitrile... Blanks with suitable words: a ) polyester shrinks on washing and melamine danger that plastics pose to the?!, pump packings, valves, seals etc pens, buttons, plugs and switches bacteria... Connector/Net 8.0 API reference once moulded can not be moulded and reset a number of smaller molecules ( )... 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