NCERT Solutions for Class 8 Science CBSE

NCERT Solutions for Class 8 Science Chapter 4 - Materials: Metals and Non-Metals

The NCERT solutions for CBSE Class 8 Science Chapter 4 Materials: Metals and Non-Metals will help you with questions asking you about the physical properties and uses of metals and non-metals. Find out what will happen when metals come in contact with water, oxygen, acids and bases. Also, revise the concept of the displacement reaction.

Elements can be divided into metals and non-metals on the basis of their physical and chemical properties.

Physical Properties of Metals and Non-metals

CuSO₄ + Fe  → FeSO₄ + Cu 

In this reaction, a more reactive iron displaces a less reactive copper from its salt solution, i.e. copper sulphate. A less reactive metal cannot displace a more reactive metal from its salt solution.

 Example: Reaction of iron metal with zinc sulphate solution

      ZnSO4 + Fe  → No displacement reaction 

 Iron metal is less reactive than zinc metal. So, a less reactive iron metal cannot displace a more reactive zinc metal from zinc sulphate solution.

· Uses of Metals

· Aluminium metal in the form of alloys is used to make aeroplanes.

· Zinc metal is used for galvanising iron to protect it from rusting.

· Silver and gold metals are used to make jewellery.

Uses of Non-metals

· Oxygen is a non-metal which is used by plants and animals for breathing.

· Nitrogen is a non-metal which is used in the manufacture of fertilisers to enhance the growth of plants.

· Chlorine is a non-metal which is used in the water purification process.

· Sulphur is a non-metal which is used in the vulcanisation of rubber.

Get a deeper understanding of the properties of metals and non-metals. Get answers for True or False questions from the CBSE Class 8 Science NCERT textbook. Revise what happens in displacement reactions while learning about elements. Also, get introduced to litmus paper tests in this chapter. Knowledge of Science facts will also improve your general knowledge and help you win quiz competitions based on Science topics.

Find answers on how gold is polished based on the scientific knowledge available about metals. This CBSE Class 8 Science chapter includes numerous such scientific facts that will make you a smarter person. That’s not all, knowledge of sodium, copper, coal, etc. will make it easier for you to understand Chemistry concepts in your higher classes.

NCERT Materials Metals and Non Metals Class 8 Videos

NCERT Materials Metals and Non Metals Class 8 Revision Notes

NCERT Materials Metals and Non Metals Class 8 Most Important Questions

NCERT Materials Metals and Non Metals Class 8 MCQ

NCERT Materials Metals and Non Metals Class 8 FIB

NCERT Materials Metals and Non Metals Class 8 Short Answer Questions

List Of Sub Chapters

Class 8 Science- Physical Properties Of Metals And Non Metals

Class 8 Science- Reaction Of Metals With Water, Acids & Bases

Class 8 Science- Reaction Of Metals And Non Metals With Oxygen

Class 8 Science- Displacement Reaction

Class 8 Science- Uses Of Metals And Non Metals

NCERT Solutions for Class 8 Science Chapter 5 - Coal and Petroleum

What is Bitumen? How does it help us? Find answers in the NCERT solutions Science free textbook solutions. Understand the key benefits of Liquefied Petroleum Gas or LPG and Compressed Natural Gas or CNG. Get the answers to true or false type questions in your textbook too. Our solutions are loaded with concept insights to make it easy for you to understand the concepts. 

Natural resources can be classified into two types:

· Inexhaustible Natural Resources: The resources which are present in unlimited quantity in nature and are not likely to be exhausted by human activities are called inexhaustible natural resources.

Examples: Sunlight, air

· Exhaustible Natural Resources: The resources which are present in a limited quantity in nature and can be exhausted by human activities are called exhaustible natural resources. 

Examples: Forests, wildlife, minerals, coal, petroleum

Fossil fuels: The natural fuels formed from the remains of living organisms buried under the Earth long, long ago are called fossil fuels.

· Coal is a hard, black, combustible mineral which consists mainly of carbon.

· It is found in deep coal mines under the surface of the Earth.

· On heating, coal, which is mainly carbon, produces carbon dioxide gas and a lot of heat energy. 

              C    +     O₂       →  ®   CO^₂      +   Heat 

· Products of Coal

     i. Coke

     ii. Coal Tar

     iii. Coal Gas

· Petroleum

· It is a dark-coloured, thick crude oil found deep below the ground in certain areas.

· Petroleum means rock oil (petra = rock, oleum = oil).

· Just like coal, petroleum is also a fossil fuel.

· Constituents of Petroleum and their Uses

· Natural Gas

· Natural gas mainly consists of methane with small quantities of ethane and propane.

· When natural gas is compressed by applying pressure, it is called compressed natural gas (CNG).

· It is a very important fossil fuel because it is easy to transport through pipes.

· It is a clean fuel.

Read our NCERT Class 8 Science solutions to understand the preparation method of Kerosene. In addition, the solutions give you accurate explanations of topics like fossil fuels, petroleum and coke. With the availability of the solutions online 24x7, you can revise the chapter at any time as per your learning plan. To understand what kinds of questions were asked in the questions recently, check the CBSE Class 8 sample paper 2020-21.

NCERT Coal and Petroleum Class 8 Videos

NCERT Coal and Petroleum Class 8 Revision Notes

NCERT Coal and Petroleum Class 8 Most Important Questions

NCERT Coal and Petroleum Class 8 MCQ

NCERT Coal and Petroleum Class 8 FIB

NCERT Coal and Petroleum Class 8 Short Answer Questions

List Of Sub Chapters

Class 8 Science- Coal And Petroleum

Class 8 Science- Petroleum And Natural Gas 

NCERT Solutions for Class 8 Science Chapter 6 - Combustion and Flame

In the NCERT solutions for CBSE Class 8 Science Chapter 6 Combustion and Flame, study combustible and non-combustible gases. Find out why goldsmiths use the outermost part of the flame to melt gold and silver. Discover the meaning of terms such as flame, combustion, fuels, fire and burning. Revise the various types of combustion with our CBSE Online Class 8 solutions.

Revisit the lessons on the process of combustion in this chapter. Understand what an ignition temperature is. Grasp the difference between wood and LPG. Through the CBSE Class 8 Science sample paper and NCERT solutions, brush up your understanding of heat generated in a burning candle. Revise the calorific value of a fuel.

A chemical process in which a substance reacts with the oxygen of the air to give heat and light is called combustion.

Magnesium   + Oxygen  Magnesium oxide + Heat + Ligh

Types of Combustion

Rapid Combustion: The reaction in which a large amount of heat and light are produced in a short period of time 

Spontaneous Combustion: The reaction which occurs on its own 

Explosive Combustion: A very fast combustion in which a large amount of heat, light and sound are produced is called explosive combustion.

· Flame and Structure of Flame

A flame is a region where the combustion or burning of gaseous substances takes place along with the evolution of heat and light.

Inner zone

· This is the dark zone which lies around the wick of the candle. It is the innermost zone of the flame.

Luminous middle zone

· The middle zone is the brightest zone of flame. In this zone, there is an inadequate supply of air.

Non-luminous zone

· The outermost zone of the flame is called the zone of complete combustion.

· This is the hottest zone of the flame.

Blue zone

· At the bottom of the flame lies a blue zone.

Fuels

· The material which is burnt to produce heat is called a fuel.

Examples: Wood, coal, LPG, kerosene, petrol, diesel, natural gas and biogas are some common fuels.

· There are three types of fuels:

o. Solid fuels

o. Liquid fuels

o. Gaseous fuels

Fuel Efficiency

· Different fuels produce different amounts of heat on burning.

· The amount of heat produced by the complete burning of 1 kilogram of a fuel is called its calorific value.

· The calorific value of a fuel is expressed in the unit of kilojoules per kilogram.

The CBSE syllabus for Class 8 Science becomes more and more interesting in this chapter as it reveals the scientific facts about things that leave you in awe. For example, find out why dry leaves are used to create fire instead of green leaves.

NCERT Combustion and Flame Class 8 Videos

NCERT Combustion and Flame Class 8 Revision Notes

NCERT Combustion and Flame Class 8 Most Important Questions

NCERT Combustion and Flame Class 8 MCQ

NCERT Combustion and Flame Class 8 FIB

NCERT Combustion and Flame Class 8 Short Answer Questions

List Of Sub Chapters

Class 8 Science- Combustion

Class 8 Science- Flame

Class 8 Science- Fuels

Class 8 Science- How Do We Control Fire?

Class 8 Science- Burning And Its Problems

NCERT Solutions for Class 8 Science Chapter 7 - Conservation of Plants and Animals

Through the NCERT solutions for CBSE Class 8 Science Chapter 7 Conservation of Plants and Animals, revise the concepts of deforestation and reforestation. Find answers on what are the differences between a zoo, a biosphere reserve and a wildlife sanctuary. Also, get answers on concepts such as flora, fauna, endangered species and extinct species.

· Deforestation is cutting down of trees or destroying forests to use the land for some other purpose.

· Reforestation is restocking of destroyed forests by planting new trees. 

· A species is an organism of a particular kind whose members can interbreed among themselves to produce fertile young ones

· Rare species exist in relatively low numbers but are not necessarily in immediate danger of extinction. Examples: Black and white ruffed lemur, Aloe polyphylla.

· An endangered species is one in which the population of organisms is at the risk of extinction. Examples: The Indian rhinoceros, the Great Indian bustard, Pink Butterfly Orchid.

· Species which exist in low numbers and may become endangered due to destruction of their habitat, overexploitation or due to some other environmental factor are called vulnerable species. Examples: The Asian elephant, Rafflesia.

· Threatened species are any species which are vulnerable to endangerment in the near future. Examples: Giant Panda, Monarch butterfly.

· Plant and animal species which are found only in a particular region and nowhere else in the world are called endemic species. Examples: Nilgiri leaf monkeys found in the Nilgiri Hills of the Western Ghats.

· A species is considered extinct when no member of the species is still alive. Examples: Dodo, Woolly Mammoth.

· Biosphere reserves or biodiversity zones are large areas of protected land for the conservation of wildlife, plant and animal resources and the traditional life of tribal people living in the area. 

· Plants naturally occurring in a particular area constitute the flora. Teak, Jamun, Fern, Mango and Arjun constitute the flora of Pachmarhi Biosphere Reserve.

· Animals naturally occurring in a particular area constitute its fauna. Cheetah, Wolf, Leopard, Chinkara, Blue bull, Barking deer and Wild dog constitute the fauna of Pachmarhi Biosphere Reserve.

· A zoo is a place where wild animals and birds live in artificial habitats such as cages and enclosures.

· A wildlife sanctuary is an area where animals are protected from any kind of disturbance such as hunting, predation and competition. 

· National parks comprise a large area of land owned by the government which is restricted from development and is protected for its landscape, flora, fauna and ecosystem on the whole. 

· Red Data Book keeps a record of all the endangered animals and plants.

· The movement of animals in large numbers from one place to another to overcome unfavourable conditions is called migration. Siberian cranes migrate to Bharatpur in Rajasthan because the environmental conditions there are more favourable as compared to Siberia, the place where they actually come from.

· Paper recycling is the process of remaking new paper products from waste paper.

Revise the NCERT CBSE Class 8 Science solutions by qualified teachers with huge experience in the field of education. These reputed teachers guide you with answers on Biosphere reserves, wildlife sanctuaries, zoos, and more. The chapter tells you about the types of species and why certain species fall under the extinct category.

Also, understand the terms flora and fauna with the examples given by our subject experts. The CBSE syllabus for Class 8 Science Chapter 7 also covers important details on global warming, green wealth, deforestation, ecological balance, and more. In this Science chapter, understand the significance of the conservation of forests and how animal poaching impacts forests. Explore CBSE Class 8 Science sample papers to practise different types of questions from this chapter.

NCERT Conservation of Plants and Animals Class 8 Videos

NCERT Conservation of Plants and Animals Class 8 Revision Notes

NCERT Conservation of Plants and Animals Class 8 Most Important Questions

NCERT Conservation of Plants and Animals Class 8 MCQ

NCERT Conservation of Plants and Animals Class 8 FIB

NCERT Conservation of Plants and Animals Class 8 Short Answer Questions

List Of Sub Chapters

Class 8 Science- Deforestation And Its Causes

NCERT Solutions for Class 8 Science Chapter 8 - Cell – Structure and Functions

Do you know how unicellular organisms are different from multi-cellular organisms? Are you aware of the purpose of nerve cells? Refresh the answers to these questions and some basic concepts on the structure of cells from earlier lessons. Revise the diagram of a plant and animal cell. The diagrams explain the features of the different types of cells and support you to write detailed answers on cells

In this chapter, one will not only learn about what cells are but also the structural organisation of cell.

· Structural Organisation of a Cell

· Study of Plant and Animal Cells