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Cbse, ncert and icse solution online, class 8 science case study question, case study question class 8 science (cbse / ncert board).

Class 8 Science Case Study Question and Answer: CBSE / NCERT Board Class 8 Science Case Study Question prepared by expert Science Teacher. Students can learn Case Based Question / Paragraph Type Question for NCERT Class 8 Science.

There are total 18 chapter Crop Production and Management, Microorganisms: Friend and Foe

, Synthetic Fibres and Plastics, Materials: Metals and Non-Metals, Coal and Petroleum, Combustion and Flame, Conservation of Plants and Animals, Cell – Structure and Functions, Reproduction in Animals, Reaching the Age of Adolescence, Force and Pressure, Friction, Sound, Chemical Effects of Electric Current, Some Natural Phenomena, Light, Stars and the Solar System, Pollution of Air and Water

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CBSE Class 8 Science Case Study Question

• Chapter 1 Crop Production and Management Case Study Question
• Chapter 2 Microorganisms: Friend and Foe Case Study Question
• Chapter 3 Synthetic Fibres and Plastics Case Study Question
• Chapter 4 Materials: Metals and Non-Metals Case Study Question
• Chapter 5 Coal and Petroleum Case Study Question
• Chapter 6 Combustion and Flame Case Study Question
• Chapter 7 Conservation of Plants and Animals Case Study Question
• Chapter 8 Cell – Structure and Functions Case Study Question
• Chapter 9 Reproduction in Animals Case Study Question
• Chapter 10 Reaching the Age of Adolescence Case Study Question
• Chapter 11 Force and Pressure Case Study Question
• Chapter 12 Friction Case Study Question
• Chapter 13 Sound Case Study Question
• Chapter 14 Chemical Effects of Electric Current Case Study Question
• Chapter 15 Some Natural Phenomena Case Study Question
• Chapter 16 Light Case Study Question
• Chapter 17 Stars and the Solar System Case Study Question
• Chapter 18 Pollution of Air and Water Case Study Question

What is Case Study Question?

Ans. At case Study there will one paragraph and on the basis of that concept some question will made. Students have to solve that question.

How many marks will have at case based question?

Most of time 5 questions will made from each case. There will 1 or 2 marks for each question.

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• Combustion and Flame Class 8 Case Study Questions Science Chapter 4

Hello students, we are providing case study questions for class 8 science. Case study questions are the new question format that is introduced in CBSE board. The resources for case study questions are very less. So, to help students we have created chapterwise case study questions for class 8 science. In this article, you will find case study questions for cbse class 8 science Chapter 4 Combustion and Flame.

Table of Contents

Case Study Questions on Combustion and Flame

(I) The air that we breathe today is more polluted than it was before. More factories more vehicles greater use of aerosols and sprays, increasing number of refrigerators and air conditioners that release CFC gases, have all contributed toward pollution. When certain chemicals from the smoke and fumes rise up into the air they mix with the water vapour in the clouds and make it acidic. When rain or snow falls from such polluted clouds, it is also acidic in nature. This acidic rain falls on the leaves of trees, on the fertile soil and also runs into lakes and rivers. The effects of the rain are disastrous. Trees slowly lose their leaves and die. Fertile soil turns acidic and damages the plants and crops. The fish and animals living in lakes or seas are killed. Even our drinking water can be affected. Many forests all over the world have suffered severe damage on account of acid rains. Before it is too late, we must try and put a stop to the millions of vehicles and chimneys pouring harmful fumes into the air.

Q.1. Which gas is released by the incomplete combustion of fuels? (a) Oxygen (b) Hydrogen (c) Carbon monoxide (d) None of the above.

Difficulty Level: Easy

Ans. Option (c) is correct. Explanation: Carbon monoxide is a poisonous gas, which is produced by the incomplete combustion of fuels.

Q. 2. Emissions of sulphur dioxide and nitrogen oxide causes: (a) Pollution (b) Acid rain (c) Deforestation (d) None of the above.

Ans. Option (b) is correct. Explanation: Acid rains are caused by emissions of sulphur dioxide and nitrogen oxide, which react with the water molecules in the atmosphere to produce acid. It has a very harmful effect on plants, land and aquatic animals and infrastructure.

Q.3. What is fire triangle?

Difficulty Level: Medium

Ans. For the generation of fire, we need three things to be present simultaneously:-

• Some sort of fuel or combustible material.
• A heat source to raise the temperature of the fuel to its ignition temperature.
• Enough oxygen to sustain combustion. So, if we remove any one of these resources, the fire can be controlled.

Q.4. How carbon dioxide is responsible for global warming?

Ans. Molecules of carbon dioxide gas have a tendency to absorb the heat. The carbon dioxide molecules present in the atmosphere absorb this heat energy and does not allow it to escape into space. So, more the amount of carbon dioxide molecules in the atmosphere more will be the temperature and eventually causes global warming.

• Chemical Effects of Electric Current Class 8 Case Study Questions Science Chapter 11
• Sound Class 8 Case Study Questions Science Chapter 10
• Friction Class 8 Case Study Questions Science Chapter 9
• Force and Pressure Class 8 Case Study Questions Science Chapter 8
• Reaching the Age of Adolescence Class 8 Case Study Questions Science Chapter 7
• Reproduction in Animals Class 8 Case Study Questions Science Chapter 6
• Conservation of Plants and Animals Class 8 Case Study Questions Science Chapter 5
• Coal and Petroleum Class 8 Case Study Questions Science Chapter 3

Microorganisms: Friend and Foe Class 8 Case Study Questions Science Chapter 2

Crop production and management class 8 case study questions science chapter 1, topics from which case study questions may be asked.

• Learning what is meant by combustion?
• Knowing types of combustion.
• Discuss various methods used to control fire.
• Learning the structure of flame.
• To know more about fuel and fuel efficiency.

We use various kinds of fuel such as petrol, diesel, CNG, LPG, coal, wood etc., in our daily life. Some of these fuels burn with a flame while some do not. This chapter deals with the chemical processes involved in burning and the type of flames produced in the processes. So based on this, the above topic list is provided.

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Case Study Questions Class 8 Science Pollution of Air and Water

Case study questions class 8 science chapter 18 pollution of air and water.

CBSE Class 8 Case Study Questions Science Pollution of Air and Water. Important Case Study Questions for Class 8 Board Exam Students. Here we have arranged some Important Case Base Questions for students who are searching for Paragraph Based Questions Pollution of Air and Water.

At Case Study Questions there will given a Paragraph. In where some Important Questions will made on that respective Case Based Study. There will various types of marks will given 1 marks, 2 marks, 3 marks, 4 marks.

CBSE Case Study Questions Class 8 Science Pollution of Air and Water

Case study 1.

Air Pollution: We can survive for some time without food, but we cannot survive even for a few minutes without air. This simple fact tells us how important clean air is to us. You already know that air consists of a mixture of gases. By volume, about 78% of this mixture is nitrogen and about 21% is oxygen. Carbon dioxide, argon, methane, ozone and water vapour are also present in very small quantities. When air is contaminated by unwanted substances which have a harmful effect on both the living and the non-living, it is referred to as air pollution. How does Air Get Polluted? The substances which contaminate the air are called air pollutants. Sometimes, such substances may come from natural sources like smoke and dust arising from forest fires or volcanic eruptions. Pollutants are also added to the atmosphere by certain human activities. The sources of air pollutants are factories, power plants, automobile exhausts and burning of firewood and dung cakes.Many respiratory problems are caused by air pollution. Let us now try to find out the substances or pollutants which are present in the polluted air. Have you noticed how rapidly the number of vehicles is increasing in our cities? Vehicles produce high levels of pollutants like carbon monoxide, carbon dioxide, nitrogen oxides and smoke. Carbon monoxide is produced from incomplete burning of fuels such as petrol and diesel. It is a poisonous gas. It reduces the oxygen-carrying capacity of the blood.Boojho remembers seeing a thick fog-like layer in the atmosphere, especially during winters. This is smog which is made up of smoke and fog. Smoke may contain oxides of nitrogen which combine with other air pollutants and fog to form smog. The smog causes breathing difficulties such as asthma, cough and wheezing in children. Many industries are also responsible for causing air pollution. Petroleum refineries are a major source of gaseous pollutants like sulphur dioxide and nitrogen dioxide. Sulphur dioxide is produced by combustion of fuels like coal in power plants. It can cause respiratory problems, including permanent lung damage. You have already studied about the burning of fossil fuels in Chapter 5. Other kinds of pollutants are chlorofluorocarbons (CFCs) which are used in refrigerators, air conditioners and aerosol sprays. CFCs damage the ozone layer of the atmosphere. Recall that the ozone layer protects us from harmful ultraviolet rays of the sun. Have you heard of the ozone hole? Try to find out about it. Thankfully, less harmful chemicals are now being used in place of CFCs. In addition to the above-mentioned gases, automobiles which burn diesel and petrol, also produce tiny particles which remain suspended in air for long periods. They reduce visibility. When inhaled, they cause diseases. Such particles are also produced during industrial processes like steel making and mining. Power plants give out tiny ash particles which also pollute the atmosphere.

Que. 1) Which among the following air pollutants reduces the oxygen carrying capacity of the blood?

(a) Carbon dioxide

(b) Carbon monoxide

(c) Nitrogen oxides

(d) Sulphur dioxide

Que. 2) ……………………………………………………………………………….. are the pollutants that are used in refrigerators, air conditioners and aerosol sprays and are known to damage ozone layer.

(a) Nitrogen dioxide

(b) Particulate matter

(c) Carbon monoxide

(d) Chlorofluorocarbons

Que. 3) The thick fog-like layer seen in the atmosphere during winters, which is a mixture of smoke and fog is known as ……………………………………………………………………………………… .

Que. 4) Define air pollution.

Que. 5) Name some of the causes of air pollution.

Que. 1) (b) Carbon monoxide

Que. 2) (d) Chlorofluorocarbons

Que. 3) (b) Smog

Que. 4) Answer: When air is contaminated by unwanted substances which have a harmful effect on both the living and non-living organisms, then it is called as air pollution.

Que. 5) Answer: Some of the causes of air pollution include: incomplete burning of fuels such as petrol and diesel, petroleum refineries, power plants, excessive use of automobiles and burning of fire wood and dung cakes.

Case study 2

The Taj Mahal: Over the past 2 decades, India’s most famous tourist attraction, Taj Mahal located in Agra, has become a matter of concern. Experts have warned that pollutants in air are discolouring its white marble. So, it is not only living organisms that get affected by polluted air but non-living things like buildings, monuments and statues also get affected. The industries located in and around Agra like rubber processing, automobile, chemicals and especially the Mathura oil refinery, have been responsible for producing pollutants like sulphur dioxide and nitrogen dioxide. These gases react with the water vapour present in the atmosphere to form sulphuric acid and nitric acid. The acids drop down with rain, making the rain acidic. This is called acid rain. Acid rain corrodes the marble of the monument. The phenomenon is also called “Marble cancer”. Suspended particulate matter, such as the soot particles emitted by Mathura oil refinery, has contributed towards the yellowing of the marble. The Supreme Court has taken several steps to save the Taj. It hasordered industries to switch to cleaner fuels like CNG (Compressed Natural Gas) and LPG (Liquefied Petroleum Gas). Moreover, the automobiles should switch over to unleaded petrol in the Taj zone. Discuss with your elders and see what they have to say about the condition of the Taj, 20 or 30 years ago! Try to procure a picture of the Taj Mahal for your scrap book.Greenhouse Effect: You know that the sun’s rays warm the earth’s surface. A part of the radiation that falls on the earth is absorbed by itand a part is reflected back into space. A part of the reflected radiation is trapped by the atmosphere. The trapped radiations further warm the earth. If you have seen a greenhouse in a nursery or elsewhere, recall that the sun’s heat is allowed to get in but is not allowed to go out. The trapped heat warms the green house. The trapping of radiations by the earth’s atmosphere is similar. That is why it is called the greenhouse effect. Without this process, life would not have been possible on the earth. But now it threatens life. Excess of CO2 in the air is one of the gases responsible for this effect. You know that CO2 is one of the components of air. You have also studiedthe role of carbon dioxide in plants. But if there is excess of CO2 in the air, it acts as a pollutant. Can you help Paheli find out the answer to her question? On the one hand, CO2 is continuously being released because of human activities. On the other hand, area under forests is decreasing. Plants utilise CO2 from the atmosphere for photosynthesis, thereby decreasing the amount of CO2 in the air. Deforestation leads to an increase in the amount of CO2 in the air because the number of trees which consume CO2 is reduced. Human activities, thus, contribute to the accumulation of CO2 in the atmosphere. CO2 traps heat and does not allow it to escape into space. As a result, the average temperature of the earth’s atmosphere is gradually increasing. This is called global warming. Other gases like methane, nitrous oxide and water vapour also contributetowards this effect. Like CO2, they are also called greenhouse gases. Global warming has become a major concern for governments worldwide. Many countries have reached an agreement to reduce the emission of greenhouse gases. The Kyoto Protocol is one such agreement. Boojho is surprised to hear that an increase in the earth’s temperature by even as little as 0.5 °C can have such a serious effect! Paheli tells him that she had read in the newspapers recently that the Gangotri glacier in the Himalayas has started melting because of global warming.

Que. 1) The phenomenon of acid rain corroding the monuments made up of marbles is known as ……………………………………………………………………………………… .

(a) Marble corrosion

(b) Monument degradation

(c) Marble cancer

(d) Monument disfiguration

Que. 2) Which among the following is the correct full form of LPG?

(a) Liquified petroleum gas

(b) Liquified pasteurised gas

(c) Liquified petroleum glass

(d) Liquified paraffin gas

Que. 3) Which among the following gases is not a greenhouse gas?

(b) Methane

(c) Nitrous oxide

Que. 4) Define the process of “acid rain”.

Que. 5) Explain the process of “greenhouse effect”.

Que. 1) (c) Marble cancer

Que. 2) (a) Liquified petroleum gas

Que. 3) (d) Oxygen

Que. 4) Answer: The pollutants like sulphur dioxide and nitrogen dioxide react with water vapour present in the atmosphere to form sulphuric acid and nitric acid. The acids drop down with rain making the rain acidic. This is called as acid rain.

Que. 5) Answer: A part of the radiation that falls on the earth is absorbed by itand a part is reflected back into space. A part of the reflected radiation is trapped by the atmosphere. The trapped radiations further warm the earth. This is known as greenhouse effect.

Case study 3

Global Warming: A Serious Threat! Global warming can cause sea levels to rise dramatically. In many places, coastal areas have already been flooded. Global warming could result in wide ranging effects on rainfall patterns, agriculture, forests, plants and animals. Majority of people living in regions which are threatened by global warming are in Asia. A recent climate change report gives us only a limited time to keep the greenhouse gases at the present level. Otherwise, the temperature may rise by more than 2 degrees Celsius by the end of the century, a level considered dangerous.What can be done? What can we do to reduce air pollution? There are many success stories in our fight against air pollution. For example, a few years ago, Delhi was one of the most polluted cities in the world. It was being choked by fumes released from automobiles running on diesel and petrol. A decision was taken to switch to fuels like CNG andunleaded petrol. These measures have resulted in cleaner air for the city. You might know of some other examples from your area regarding reduction of air pollution. Share these with your friends.Do you know about the “Say no to crackers” campaign which was organised by children from many schools? This made a big difference to the air pollution levels around Diwali.The quality of air at various locations is monitored regularly by government and other agencies. We can use this data to generate awareness about air pollution among friends and neighbours. There is a need to switch over to alternative fuels instead of the fossilfuels for our energy requirements. These could be solar energy, hydropower and wind energy.Small contributions on our part can make a huge difference in the state of the environment. We can plant trees and nurture the ones already present in the neighbourhood. Do you know about Van Mahotsav, when lakhs of trees are planted in July every yearBoojho and Paheli once happened to go to an area where some people were burning dry leaves. They started coughing because the entire area was full of smoke. Paheli thought it would be a better option to put them in a compostpit rather than burning. What do youthink?

Que. 1) Majority of people living in regions which are threatened by global warming are in ……………………………………………………………………………………………… .

(a) America

(d) Antarctica

Que. 2) A decision was taken by the Delhi government to switch to fuels like?

(b) Unleaded petrol

(c) Both (a) and (b)

(d) None of the above

Que. 3) To reduce the drastic effects of air pollution we should ……………………………………………………………………………………… .

(a) Say no to crackers

(b) Plant more trees

(c) Use safer fuels like CNG and LPG

(d) All of the above

Que. 4) What is “Van Mahotsav”?

Que. 5) What are the effects of global warming?

Que. 1) (c) Asia

Que. 2) (b) Both (a) and (b)

Que. 3) (d) All of the above

Que. 4) Answer: Van Mahotsav is celebrated in the month of July every year, when lakhs of trees are planted. Planting large amounts of trees can help reduce the amount of carbon dioxide from the environment.

Que. 5) Answer: Some of the effects of global warming include less rainfall, drought, hotter temperatures, more severe storms, loss of species, etc.

Case study 4

Water Pollution: In Class VII you learnt that water is a precious resource. We saw that water is becoming scarce due to increase in population, industries and agricultural activities. You have also studied how water becomes “dirty” after we use it for washing clothes, bathing, etc. This means that we are adding some materials to the water, which spoil its quality and change its smell and colour. Whenever harmful substances such as sewage, toxic chemicals, silt, etc., get mixed with water, the water becomes polluted. The substances that pollute water are called water pollutants.How does Water Get Polluted? Case Study: Ganga is one of the most famous rivers of India. It sustains most of the northern, central and eastern Indian population. Millions of people depend on it for their daily needs andlivelihood. However, recently a study by the World-Wide Fund for Nature (WWF) found that Ganga is one of the ten most endangered rivers in the world. The pollution levels have been rising for many years. We have reached this stage because the towns and cities, through which the river flows, throw large quantities of garbage, untreated sewage, dead bodies, and many other harmful things, directly into the river. In fact, the river is ‘dead’ at many places where the pollution levels are so high that aquatic life cannot survive. An ambitious plan to save the river, called the Ganga Action Plan was launched in 1985. It aimed to reduce the pollution levels in the river. However, the increasing population and industrialisation have already damaged this mighty river beyond repair. Now, the Government of India has launched a new initiative known as National Mission for Clean Ganga (NMCG) in 2016. Let us take a specific example to understand the situation. The Ganga at Kanpur in Uttar Pradesh (U.P.), has one of the most polluted stretches of the river. Kanpur is one of the most populated towns in U.P. People can be seen bathing, washing clothes and defecating in the river. They also throw garbage, flowers, idols of gods and goddesses and non- biodegradable polythene bags into the river. At Kanpur the amount of water is comparatively small and the flow of the river is very slow. In addition, Kanpur has more than 5000 industries. These include fertiliser, detergent, leather and paint industries. These industrial units discharge toxic chemical wastes into the river. Based on the above information think of the answers to the following questions:

• What are the factors responsible for pollution of the river?
• What steps can be taken to restore the river Ganga to its past glory?
• How would the disposal of garbage, etc., affect the living organisms in the river?

 Many industries discharge harmful chemicals into rivers and streams, causing the pollution of water. Examples are oil refineries, paper factories, textile and sugar millsand chemical factories. These industries cause chemical contamination of water. The chemicals released include arsenic, lead and fluorides which lead to toxicity in plants and animals. There are regulations to prevent this. Industries are supposed to treat the waste produced before discharging it into waters, but quite often the rules are not followed. The soil is also affected by impure water, causing changes in acidity, growth of worms, etc. We have learnt in Chapter 1 the importance of pesticides and weedicides for the protection of crops. However, all these chemicals dissolve in water and are washed into water bodies from the fields. They also seep into the ground to pollute ground water. Have you seen ponds which look green from a distance because they have a lot of algae growing in them? This is caused by excessive quantities of chemicals which get washed from the fields. These act as nutrients for algae to flourish. Once these algae die, they serve as food for decomposers like bacteria. A lot of oxygen in the water body gets used up. This results in a decrease in the oxygen level which may kill aquatic organisms.Sometimes untreated sewage is thrown directly into rivers. It containsfood wastes, detergents, microorganism, etc. Can ground water get polluted by sewage? How? Water contaminated with sewage may contain bacteria, viruses, fungi and parasites which cause diseases like cholera, typhoid and jaundice. The bacteria present in the faeces of mammals are indicators of the quality of water. If water has these bacteria, it means that it has been contaminated by faecal matter. If such water is used by us, it can cause various infections.Paheli explains that water which looks clean may still have disease- carrying microorganisms and dissolved impurities. So, it is essential to purify water before drinking, for example, by boiling. Water which is suitable for drinking is called potable water. You have seen how various physical and chemical processes in the sewage treatment plants help to clean water before discharging it into water bodies. Similarly, municipal bodies treat the water before supplying it to households.Let us see how water can be made safe for drinking:

• You have already seen how water is filtered. This is a physical method of removing impurities. A popular household filter is a candle type filter.
• Many households use boiling as a method for obtaining safe drinkingwater. Boiling kills the germs present in the water.
• Chlorination is a commonly used chemical method for purifying water. It is done by adding chlorine tablets or bleaching powder to the water. We must be cautious. We should not use more chlorine tablets than specified.

Laws for industrial units should be strictly implemented so that polluted water is not disposed off directly into rivers and lakes. Water treatment plants should be installed in all industrial areas. At our individual levels we should consciously save water and not waste it. Reduce, reuse and recycle should be our mantra! Think of your daily routine – how can you save water? We can think of creative ideas like reusing water used for washing and for other household tasks. For example,water used for washing vegetables may be used to water plants in the garden. Pollution is no longer a distant phenomenon. It is affecting the quality of our daily lives. Unless we all realise our responsibility and start using environment-friendly processes, the very survival of our planet is in danger.

Que. 1) Government of India launched which of the following initiative in 2016 for the purpose of cleaning river ganga?

(a) International mission for clean ganga

(b) National mission for clean ganga

(c) National mission for renewing ganga

(d) National mission for renovating ganga

Que. 2) The harmful substances such as sewage, toxic chemicals, silt, etc get mixed with water to pollute the water. These harmful substances are called ……………………………………………………………………………………… .

(a) Water rodents

(b) Disinfectants

(c) Water pollutants

(d) Zooplanktons

Que. 3) How can the chemical contamination of water be reduced by the industries?

(a) The Industrial waste should be treated before discharging into water.

(b) Industries should throw chemical waste into the water bodies.

(c) Industries should stop working.

(d) Industries should discharge the waste into the middle of water bodies.

Que. 4) Name some of the measure by which water can be made safe for drinking.

Que. 5) What all are the main causes of pollution of the river Ganga?

Que. 1) (a) National mission for clean ganga

Que. 2) (c) Water pollutants

Que. 3) (a) The industrial wastes should be treated before discharging into water.

Que. 4) Answer: Some of the measures that can be taken to make the water safe for drinking include, filtering of water, boiling of water, Chlorination of water.

Que. 5) Answer: Increasing populations and industrialization are the causes of pollution of river Ganga. Some other causes include people taking bath, washing clothes and defecating in the river. Throwing flowers, garbage, idols of non-biodegradable materials and polyethene bags.

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Case Study Based Questions: Friction | Science Class 8 PDF Download

Read the given passage below and answer the question:

The force required to overcome friction at the instant an object starts moving from rest is a measure of static friction. On the other hand, the force required to keep the object moving with the same speed is a measure of sliding friction. The sliding friction is slightly smaller than the static friction.

When one body rolls over the surface of another body, the resistance to its motion is called rolling friction. Rolling reduces friction. It is always easier to roll than to slide a body over another.

Q1: The following options show arrangement of types of friction according to decreasing order of applied friction. Select the correct order. (a) Rolling > Sliding > Static (b) Static > Rolling > Sliding (c) Sliding > Static > Rolling (d) Static > Sliding > Rolling Ans: (d)

Q2: In which of the following case one will have to apply maximum force? (a) Riding a bicycle (b) Trying to move a heavy rock from its resting place (c) Swimming in a pool (d) Drilling a hole in a wall Ans: (b)

Q3: Oiling or greasing in machine parts: (a) Increases the friction between the parts (b) Decreases the friction between the parts (c) Both (a) and (b) are correct. (d) None of the above Ans: (b)

Q4: Why static friction is more than sliding friction? Ans: The friction is caused by the interlocking of irregularities in the two surfaces. It is obvious that the force of friction will increase if the two surfaces are pressed harder. The force required to overcome friction at the instant an object starts moving from rest is a measure of static friction. On the other hand, the force required to keep the object moving with the same speed is a measure of sliding friction. When the box starts sliding, the contact points on its surface do not get enough time to lock into the contact points on the floor. So, the sliding friction is slightly smaller than the static friction.

Q5: Classify the given examples into static, sliding, and rolling friction: Static Friction: Papers on a table, car parked on a hill. Sliding Friction: A box sliding on an inclined plane, child playing on slide in a park. Rolling Friction: Ball moving on the ground, tyres of a bus.

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NCERT Solutions for Class 8 Science

NCERT Solutions Class 8 Science includes a variety of foundational principles covering multiple branches such as physics, chemistry, and biology. These comprehensive solutions create a clear, step-by-step explanation of the concepts designed by Allen's Experts to ensure students develop a thorough understanding of these principles. 

These solutions make complex concepts and in-depth explanations of each diagram and practical activity easy for students. Along with consistent practice, these solutions clarify every topic, thus becoming the most essential tool for any student preparing to score good marks in their exam.

• 1.0 NCERT Solutions Class 8 Science - Download Free PDFS

 The following Chapters have been removed from NCERT Class 8 Science for the Academic year 2024-25

• Synthetic Fibres and Plastics
• Materials: Metals and Non-Metals 
• Cell Structure and Functions
• Stars and The Solar System 
• Pollution of Air and Water 
• 2.0 Features of ALLEN’s NCERT Solutions Class 8 Science
• Class 8 NCERT Science Solutions provides complete, step-by-step solutions for each chapter, clearly guiding students through each concept.  
• They are prepared carefully by the experienced faculties at Allen, and cover the entire syllabus, ensuring accuracy.  
• Includes explanatory notes of all diagrams, charts, and practical activities to facilitate understanding of the concepts.
• Follows the exact NCERT textbook structure, ensuring students stay aligned with the CBSE curriculum.
• Practice problems ensure that concepts are continuously revisited, preparing the student to improve analytical and problem-solving skills.
• Solutions are designed to be engaging, presenting concepts to the student in a structured manner facilitating active learning and retention.
• Available in digital format, allowing students to access high-quality solutions anytime for effective revision.

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The NCERT Solutions provide step-wise and detailed solutions to NCERT textbook chapter-wise problems, explaining complex concepts in an easy-to-grasp way. While immersed in these step-wise solutions, students start developing a concrete approach and problem-solving skills, which increases their speed and accuracy while not only effectively preparing but also building students a lot of confidence.

Yes, all the NCERT Solutions given above in this article for each chapter are ensured that they are updated with the latest syllabus.

Yes, these solutions often include explanations for practical activities, diagrams, and real-life applications, which help students better grasp the scientific concepts behind them.

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Case Study Questions for Class 8 Science Chapter 6 Combustion and Flame

• Last modified on: 1 year ago
• Reading Time: 4 Minutes

Here we are providing case study questions for CBSE Class 8 Science Chapter 6 Combustion and Flame.

Case Study Questions

Question 1:

Read the passage carefully and attempt the questions given below.

A chemical process in which a substance reacts with oxygen to give off heat is called combustion. The substance that undergoes combustion is said to be combustible. It is also called a fuel. The fuel may be solid, liquid or gas. Sometimes, light is also given off during combustion, either as a flame or as a glow. The lowest temperature at which a substance catches fire is called its ignition temperature. The substances which have very low ignition temperature and can easily catch fire with a flame are called inflammable substances. Examples of inflammable substances are petrol, alcohol, Liquefied Petroleum Gas (LPG)

i) What are combustible substance? a) Substance that undergoes combustion b) Substance reacts with ozone c)Substance that glows d) All of these

ii) Fuels can be : a) Solids only b) Liquids only c) Gases only d) All of these

iii) What is ignition temperature? a) Lowest temperature at which a substance catches fire. b) Temperature when water boils c) Temperature at which ice is formed d) Temperature of LPG.

iv) Identify the inflammable substance from the following. a) Soil b) Water c) Alcohol d) Vinegar

v) What are inflammable substances? a) Substances with low ignition temperature b) Substances which catches fire easily with a flame c) Only option a d) Both a and b

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