NCERT Solutions for Class 8 Science play an important role in your annual exam preparation, especially when you have doubts in NCERT Class 8 Science textbook. These solutions have been prepared by Goprep's subject matter experts having years of experience in teaching the subject of Science. Further, these NCERT Class 8 Science Solutions include answers to all the questions given in the NCERT Science Book Class 8. These solutions have been prepared in compliance with the latest curriculum of the CBSE for Class 8 Science.
Science is particularly a subject in class 8 that lays the foundation for subjects such as Physics, Chemistry, and Biology in Class 9th. So, in this regard, it gets important for you to prepare each chapter carefully in Class 8th. With our researched and detailed NCERT Class 8th Science Solutions, you can solve complex questions and prepare difficult topics quite satisfactorily. Moreover, you can check and access chapter-wise solutions for NCERT Class 8 Science Book is given below.
|1 Crop Production and Management1 Exercises|11 Questions|
|2 Microorganisms: Friend and Foe1 Exercises|9 Questions|
|3 Synthetic Fibres and Plastics1 Exercises|15 Questions|
|4 Materials: Metals and Non-Metals1 Exercises|11 Questions|
|5 Coal and Petroleum1 Exercises|9 Questions|
|6 Combustion and Flame1 Exercises|13 Questions|
|7 Conservation of Plants and Animals1 Exercises|11 Questions|
|8 Cell - Structure and Functions1 Exercises|11 Questions|
|9 Reproduction in Animals1 Exercises|12 Questions|
|10 Reaching The Age of Adolescence1 Exercises|12 Questions|
|11 Force and Pressure1 Exercises|10 Questions|
|12 Friction1 Exercises|10 Questions|
|13 Sound1 Exercises|13 Questions|
|14 Chemical Effects of Electric Current1 Exercises|12 Questions|
|15 Some Natural Phenomena1 Exercises|12 Questions|
|16 Light1 Exercises|17 Questions|
|17 Stars and The Solar System1 Exercises|16 Questions|
|18 Pollution of Air and Water1 Exercises|11 Questions|
Introduction: In recent times, the population explosion has led to an increase in demand for food. To provide food to a large population, it has become necessary for farmers to adopt smart and efficient agricultural practices.
A crop can be defined as a plant that can be grown and harvested to get plant products such as grains, pulses, vegetables etc. In India, crops can be classified into two types based on seasons- Rabi and Kharif crops.
Basic practices of crop production in a sequential manner are given as- preparation of soil, sowing, the addition of manure and fertilizers, irrigation, protection from weeds, harvesting, and storage. The last topic of the NCERT Class 8 Science Chapter-1 will revolve around animal husbandry.
Animal husbandry is the process of obtaining food from animals that are raised for eggs, milk, meat etc. Once you complete this chapter, you will feel confident enough to attempt 11 questions present at the back exercise of chapter-1.
List of Topics in “Crop Production and Management”
Introduction: Microorganisms are tiny organisms that cannot be seen with the naked eye. However, these organisms can be examined under the microscope. They can thrive in harsh conditions, ranging from polar to hot springs and deserts to marshy lands.
Based on the number of cells inside their body, they can be classified as unicellular or multicellular. Generally, microorganisms can be found in air and water. Besides, they also act as parasites by living in the bodies of hosts such as animals and plants.
Microorganisms that exist extensively in nature include bacteria, fungi, protozoa, and blue-green algae. Some of these microorganisms are pathogens, i.e. they can spread disease when they enter inside the host organisms.
On the other hand, some of the microorganisms are useful as they can decompose organic waste and dead plants and animals into simpler substances. Find out how these tiny organisms are useful for plants and animals in NCERT Solutions for Class 8 Science Chapter-2.
List of Topics in “Microorganisms: Friend and Foe”
Introduction: In the previous edition of NCERT Science textbook, you learnt that natural fibres are obtained from plants or animals such as cotton, wool, silk, to name a few. This year, you will study about synthetic or man-made fibres that are made up of very large units called polymers.
Synthetic fibres can be prepared by chemical processing of petrochemicals. Like natural fibres, these fibres can be woven into fabrics. Synthetic fibres are being used in the making of many household articles such as buckets, containers, furniture, ropes etc.
Synthetic fibres can be classified into acrylic, rayon, nylon and polyester, depending upon the types of chemicals used in their creation. These fibres differ from one another in their cost, durability, nature of burning, water-absorbing capacity etc.
Today, life without plastics cannot be imagined as these are being extensively used almost everywhere. However, the waste created by plastics is causing harm to the environment as they cannot be decomposed by microorganisms. Getting rid of them through burning is also not a solution as it will lead to emission of poisonous gases.
To conclude, you should limit the use of plastics and adopt 5R principle wherever possible. After the end of this chapter, you will come across 15 questions based on the following topics.
List of Topics in “Synthetic Fibres and Plastics”
Introduction: Metals can be distinguished from non-metals based on their physical and chemical properties. Lustre and hardness are two of the physical properties to identify a metal. Other properties of metals are that they exhibit ductility, malleability, and conductivity.
When metals are burnt in reaction with oxygen, they produce metal oxides that are basic in nature. On the other hand, non-metals on burning in the presence of oxygen produces non-metallic oxides which are acidic in nature.
Metals on reacting with water lead to the formation of metal hydroxides and hydrogen gas. On the other hand, non-metals do not react with water. Further, metals also react with acids to produce metal salts and hydrogen gas.
Today, metals are used in making aircraft, automobiles, cooking utensils, industrial gadgets, water boilers, etc. Non-metals find its applications in chemical industries, water purification process, production of crackers etc. The back-exercise of NCERT Class 8 Science Chapter-4 includes 11 questions.
List of Topics in “Materials: Metals and Non-Metals”
Introduction: Previously, you have learnt about natural resources such as sunlight and air, which are present in unlimited quantity. Such resources are also termed as inexhaustible resources.
While some resources are limited in nature and take years for their replenishment, which are called exhaustible resources. Examples of such resources include coal, forests, minerals, natural gas, petroleum, wildlife etc.
Through sustainable use of nonrenewable or exhaustible resources, you can prevent the overuse of fossil fuels. Fossil fuels were formed from the dead remains of living organisms and takes millions of years to get replenished.
Petroleum gas, widely known as ‘black gold’, is currently the main source of fuel for vehicles. Its overconsumption in recent times has led to a decline in its volume, which can now take years to get replenished. Therefore, you should use fossil fuels judiciously. In total, there are 9 exercise questions that will revolve around the topics given below.
List of Topics in “Coal and Petroleum”
(a). Story of Coal
(c). Coal Tar
(d). Coal Gas
(a). Refining of Petroleum
3. Natural Gas
4. Some Natural Resources are Limited
Introduction: You must be familiar with the term ‘combustion’ from previous classes. A substance is said to be combustible when it burns in air. You must have observed the label of deodorant containers indicating that they are inflammable if the droplets get exposed to fire.
Oxygen is essential for carrying out the process of combustion. During this process, heat energy is released. Inflammable substances have very low ignition temperature. Water is commonly used to control fires, but it will aggravate the condition in case of fire caused due to electrical equipment or oils.
The types of combustion discussed here are rapid combustion, spontaneous combustion, explosion, etc. Incomplete combustion of fuel emits poisonous carbon monoxide gas, which along with other greenhouse gases cause global warming.
Observe the three different zones of a flame carefully. The outer zone is the hottest part of the flame and appears to be blue in color. The middle zone appears yellow in color and moderately hot. The innermost zone is the least hot and black in color.
List of Topics in “Combustion and Flame”
Introduction: Plants and animals living in a particular region are known as flora and fauna of that region. Wildlife sanctuaries, national parks and biosphere reserve are names given to the areas meant for conservation and preservation of forest and wild animals.
Different countries have different types of living organisms. Such living organisms living in a particular area are part of the biodiversity of that place. For instance, you will find Kangaroos in Australia, Kiwis in New Zealand etc. Kangaroos and Kiwis can also be classified under endemic species as they are found only in these regions.
Earlier, the population of Tigers in India was declining at an alarming rate, which made them an endangered species. However, the government prohibited hunting of Tigers due to which they are out of danger of extinction. Red Data Book preserves a record of endangered species.
In case of unfavourable conditions, a species belonging to a particular region migrate to some other habitat for a particular time period every year. Examples of migratory birds or animals, include Siberian Cranes, Greater Flamingo, Butterfly, to name a few.
After reading the entire chapter, you will find 11 questions in the back exercise of chapter-7.
List of Topics in “Conservation of Plants and Animals”
Introduction: In previous classes, you studied that a cell is the smallest structural and functional unit of the human body. A group of cells combine together to form a tissue. Further, these tissues together form muscles, which ultimately leads to the formation of organs.
In 1665, Robert Hooke discovered cells when he took a sample of cork cells and observed them under the microscope. After this discovery, many scientists began their research on different types of cells. They found that cells vary in shape and size.
Based on the number of cells, organisms are classified under unicellular and multicellular organisms. Examples of unicellular organisms are bacteria, amoeba, plankton etc. Some common examples of multicellular organisms are animals and plants.
As per the observations made by scientists, a cell has three main components, including cell membrane, cytoplasm, and the nucleus. Cells without a nuclear membrane are called prokaryotic cells, whereas those with the enclosed nucleus are called eukaryotic cells.
Once you are thorough with the NCERT Class 8 Science Chapter-8, you can attempt 11 questions present at the back exercise.
List of Topics in “Cell Structure and Functions”
Introduction: Recall the process of reproduction from the previous edition of NCERT Science textbook. It is essential for organisms to reproduce if they want to sustain their existence. In simple words, reproduction refers to the continuation of species, generation after generation.
There are two modes of reproduction- sexual and asexual reproduction. Sexual reproduction involves the fusion of male and female gametes to form a zygote, which develops into a full-grown baby over the course of 9 months. This mode of reproduction ensures variations in species that enable them to survive even in unfavourable conditions.
Male reproductive organs consist of a pair of testicles, sperm ducts and penis. Female reproductive organs include a pair of ovaries, oviducts, and uterus. When fertilization takes place inside the female body, it is called internal fertilization. For example- human beings, cows, dogs, etc.
On the other hand, asexual reproduction involves only one parent body due to which there are no variations in new individuals. Hydra develops from buds with the process called budding. Amoeba performs binary fission to separate into two halves.
It is recommended that you cross-check your answers from our NCERT Solutions to give a precise explanation.
List of Topics in “Reproduction in Animals”
Introduction: In the previous chapter, you studied that human beings and other animals can reproduce only after reaching a certain age. In this chapter, we will discuss changes that are responsible for sexual maturation. You will also get to understand the role of hormones and how they induce changes in your body after puberty.
Generally, puberty sets in between the age of 11 and 16 years. Most noticeable changes that are observed at the onset of puberty include growth of reproductive organs, hair growth, and change of voice. Besides, it is at this age when children reach their maximum height.
The changes induced in the body during puberty and sexual maturation both are controlled by hormones. Endocrine glands also called ‘ductless glands’, are responsible for the secretion of different hormones directly into the bloodstream.
The pituitary gland, also known as the master gland, is responsible for secreting growth hormones and hormones that make other glands such as adrenaline, testes, thyroxine, and ovaries. Testosterone and estrogen are male and female hormones, respectively. In total, there are 12 questions based on the following topics.
List of Topics in “Reaching the Age of Adolescence”
Introduction: Recall from previous classes, force is defined as a push or a pull. Force can bring a moving object to rest or bring the object to motion from resting position. It represents both magnitude as well as direction.
Apart from the factors mentioned above, a force can increase or decrease the speed of an object. It can also change the shape and size of an object. A force can act on an object with or without being in contact with it.
Based on the interaction between two objects, a force can be categorized into contact and non-contact forces. Contact force exists when two objects are in contact with each other. When there is no contact between the two objects, the force acting between them is called non-contact force.
Examples of contact forces include muscular force and frictional force. Magnetic force, electrostatic force, and gravitational force are examples of non-contact forces. Finally, the last topic of this chapter is centred around pressure and how liquids/gases exert pressure on the walls of their containers. NCERT Solutions for Class 8 Science Chapter-11 consists of answers to all 10 questions present in the back exercise.
List of Topics in “Force and Pressure”
Introduction: In NCERT Class 8 Science Chapter-12, you will study that frictional force acts in the opposite direction to that of muscular force. The force of friction depends on three factors, including the nature of surfaces in contact, state of smoothness, and hardness of two surfaces.
Friction arises when there are irregularities on the two surfaces in contact. Due to irregularities between their surfaces, there is interlocking between them. As a result, the force of friction is greater if a rough surface is involved.
Friction is of three types- rolling, sliding, and static. Static friction acts when we apply force on an object, which is at rest. Sliding friction, on the other hand, comes into play when an object slides over another. In case of rolling friction, one body rolls over the surface of another body.
Frictional force can be increased by making a surface rough, whereas it can be reduced by using lubricants. In industries, workers reduce the friction in machines by using ball bearings.
Finally, you will learn that fluids also exert the force of friction on objects in motion through them. This type of frictional force is called fluid friction. You will find 10 questions in the back-exercise of this chapter.
List of Topics in “Friction”
Introduction: Sound is defined as vibrations that require a medium to travel for its propagation. With the help of sound waves, we are able to communicate with one another. In the previous class, you have already studied about vibrations, which exhibit to and fro motion.
Vibrations in the body are responsible for producing sound. In human beings, the vibration of the vocal cords produces sound. The number of oscillations or vibrations per second is called the frequency of oscillation.
Frequency can be measured in hertz (Hz). The loudness of sound is directly proportional to the amplitude of vibration, i.e. the larger the amplitude of vibration, the louder is the sound.
Also, the pitch and shrillness depend on the frequency of vibration. Higher the frequency of vibration, higher will be the pitch and shrillness. The last topic of this chapter is centred around noise, its prevention and health problems associated with it.
List of Topics in “Sound”
Introduction: In earlier classes, you have learnt to distinguish between conductors and insulators. Conductors allow the electric current to pass through them whereas insulators do not allow the electric current to pass through them.
Examples of conductors are metals such as copper and aluminium. Some common examples of insulators are rubber, plastic and wood. Further, you will discover that solutions of acids, bases and salts also conduct electricity.
When electric current is passed through a conducting liquid, then it causes chemical reactions. In this chapter, you will also learn about electroplating, which refers to the process of deposition of a layer of any desired metal on another metal, by means of electricity.
This chapter features 12 questions in its back-exercise. We have provided NCERT Solutions for all its exercise questions.
List of Topics in “Chemical Effects of Electric Current”
Introduction: In NCERT Class 7 Science textbook, you read about winds, storms and cyclones. Cyclones can cause mass destruction to human life and property. In this chapter, you will study two other destructive natural calamities, which are earthquakes and lightning.
As you proceed, you will learn that two objects can be charged when they are rubbed against each other. Out of these two objects, one carries a positive charge, and the other carries a negative charge.
When electric charges are produced by rubbing, they are called static charges. With the help of electroscope, one can detect whether a body carries a charge or not. Further, you will find out that the flow of electrons constitutes an electric current.
You must have seen a green wire which is used in the grounding of an electric circuit. Through this wire, charges are transferred from a charged body to the earth. This process is known as earthing.
After you complete NCERT Class 8 Science Chapter-15, you will understand how earthquake and lightning occurs. There are 12 questions that are framed from the following topics.
List of Topics in “Some Natural Phenomena”
Introduction: Light is a form of energy that allows us to see objects. Although we are gifted with the sense of sight, eyes alone cannot see any object. When light from an object enters our eyes, then only we are able to see an object.
In this chapter, we will discuss two laws of reflection. The first law of reflection states that the angle of incidence is always to the angle of reflection. The second law states that incident ray, reflected ray and the normal, all lie in the same plane.
Previously in Chapter-15 of NCERT Class 7 Science textbook, you read that a polished surface acts as a mirror on which regular reflection takes place. Diffused reflection, on the other hand, takes place when light is incident on a rough surface.
The concept of lateral inversion is something you experience everyday when you stand in front of a mirror. When you raise your right hand, you will see your left hand raised and vice versa. Further, you will learn the construction and applications of a kaleidoscope.
As you continue reading the chapter, you will study about dispersion, components of the human eye, and Braille system. There are 17 questions that will cover all the concepts mentioned below.
List of Topics in “Light”
Introduction: Our solar system comprises the stars, the planets, the moon, and many other objects in the sky. These are called celestial objects. Have you ever wondered what causes different phases of the moon? Apart from the full-moon day, we are able to see only that part of the moon which reflects the light of the sun towards us.
Stars are luminous objects that have their own light. For example- the sun is also a star. You can calculate the distance of several celestial objects from your planet in light-years.
A group of stars is referred to as a constellation. Virtually, these groups of stars make recognizable shapes. Apart from Mercury and Venus, all the planets in our solar system have their own moon.
Moon acts as a natural satellite of the Earth. However, our day-to-day communication is carried out with the help of artificial satellites. Besides, these satellites are also used for weather forecasting, long-distance communication, and remote sensing.
List of Topics in “Stars and the Solar System”
Introduction: In previous classes, you have learnt about the harmful changes taking place in our surroundings. Air pollutants have made our surroundings contaminated as these are composed of harmful gases. These include carbon monoxide, carbon dioxide, nitrogen oxide, sulphur dioxide, and methane.
The level of carbon dioxide gas is on the rise due to industrial pollution, vehicle emissions, forest fires etc. This increased level of carbon dioxide has led to global warming. In the latter half of NCERT Class 8 Science Chapter-18, you will study about water pollution and its causes.
List of Topics in “Pollution of Air and Water”
Given below are some of the most frequently asked questions that students come up in regards to NCERT Solutions for CBSE Class 8 Science. These FAQs will keep all your doubts at bay and form clarity regarding the significance of Class 8 Science NCERT Solutions.
NCERT Solutions for Class 8 comprise of detailed and easy solutions for the questions given in the NCERT Science Book Class 8. These solutions have been prepared by our expert teachers in accordance with the latest syllabus of Class 8 Science.
The NCERT Class 8 Science Solutions comprise of solutions and explanations for all the questions and topics that are given in the NCERT Science Textbook of Class 8. The solutions are well researched and detailed in nature and help students grasp important and complex topics quite satisfactorily.
Since CBSE publishes its textbook for Class 8 Science, it cannot be concluded that CBSE recommends other sources of study. However, the NCERT Solutions that we make available are strictly based on the questions published in the NCERT Science Book of Class 8.
So, you can certainly take the help of these solutions to supplement your preparation and perform better in the exam.
NCERT Solutions made available by us comprise of detailed and easy answers and explanations for the questions given in NCERT Science Textbooks. So, if you are preparing for the exam from both these sources, then it is certainly enough and would enable you to come good in the exam.
Science is a subject that needs thorough preparation to score good marks in the exam. So, only studying the textbook may limit your chances of securing better marks in the exam. So, we suggest you rely on the CBSE Class 8 Science Solutions provided by us to clear your concepts and perform better in the exam.