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Having weak concepts of science might lead to unprecedented consequences. NCERT textbook for class 8 science is recommended by several teachers. The right mix of NCERT textbook and NCERT solutions for class 8 science will not only helps you to score good marks but also build a solid foundation in science. NCERT solutions prepared by the Physics Wallah team is one of the best available solutions on the web.
Since the syllabus of science subjects in class 8 is very large, it is crucial for students to get through a channelized manner. We enforce specially devised strategies helpful for exam preparation. The NCERT solutions for class 8 Science is useful in terms of revision just before the examination.
The NCERT solutions for class 8 Science have been secluded in a very concise manner. Our expert faculties at Physics Wallah have done a detailed analysis of previous year's question papers before preparing the solutions.
Read the chapter before attempting an exercise of the NCERT textbook Try to solve the question by yourself and take the help from NCERT solutions of class 8 science only when you can’t solve the question by yourself. The team at Physics Wallah comprises of experts with years of experience. The NCERT solutions for class 8 Science is checked thoroughly many times in order to ensure the study material is flawless. The study material provided by Physics Wallah is preferred by the toppers of all the schools. The much-diversified nature of study material helps students to acknowledge very easily. The NCERT solutions for class 8 Science is your gateway to becoming a topper in the class.
We have prepared solutions for each and every question as per the guideline of CBSE and before uploading to the web it is procreated several times. These solutions are helpful in scoring the required marks in the examination. The NCERT solutions for class 8 Science have been prepared by extensive research of the generalized paper format. The NCERT solutions for class 8 Science have been useful in easy sharing among friends. The very foundation of Physics Wallah has been laid on providing free education to the needy. The complete NCERT solutions for class 8 Science are available in Pdf format and can be accessed on variable devices.
To have the right approach for class 8 science one must follow these points
Science is among the most crucial subject for students looking forward to making their careers in the science stream. The team at Physics Wallah comprises of experts from various fields. The faculty preparing NCERT solutions for class 8 Science have years of experience in teaching science subjects. We wish to help students score the topmost marks.
The syllabus of NCERT solutions for class 8 Science acts as a foundation for students in the future. Too many students' science syllabus might not be as easy to comprehend and understand. We have a one-stop solution for students to resolve their problems. The team at Physics Wallah comprises of experts with complete knowledge of the paper pattern of exams.
NCERT textbook explains things required for Crop Production and Management. You will learn how Our planet has a rich variety of life but it is under threat because humans are using up more and more of the earth’s resources, producing more waste, and causing more pollution. Plants and animals are disappearing or becoming endangered species at an alarming rate. Every few years, the international conservation union updates a list of species that are in danger of becoming extinct.
The world of living creatures that are present everywhere but are too small to be seen with the naked eye, is said to be a world of micro-organisms. They are omnipresent; found floating in the air and in water, moving about in the soil and on plants, inside our bodies and those of all animals. Some of these tiny creatures are disease-causing (germs). However, most are harmless. To know more about this world, let us explore the chapter.In this chapter, you will learn about Microorganisms: Categories, and habitats. Useful microorganisms, harmful microorganisms. Food preservation. Nitrogen fixation. Nitrogen cycle.
Clothes are an expression of a person. We are judged by the type of clothes we wear. Have you ever wondered, what these clothes are made of? All of us use materials like nylon stockings and ropes. Plastic goods are an integral part of our lives. Let us understand what materials makeup plastics. This chapter covers Synthetic fibers: Rayan, Nylon, Terylene, PET, Polyethene terephthalate, Acrylic, and Koroseal. Plastics: Thermoplastics, thermosetting plastics, polyethylene, polypropene, PVC, Teflon, Polystyrene, Plastics, and environment.
This chapter deal with the properties of metal and non-metal learn how to identify what are the basic difference in chemical and physical properties of metal and non-metal with the appropriate example given in the NCERT text book. Read all the important reaction related to metal and non-metal and how they react with acid-base and their fundamental properties. You have already studied about elements as being pure substances that each are made up of one kind of atoms only.
For the convenience of study, these elements are divided into two broad classes: Metals and non-metals. This division of elements is based on the fact that there are certain properties that are found only in metals and certain others that are found only in non-metals. But, there are also some elements that show the properties of both metals and non-metals. They are known as metalloids. Some common metalloids are arsenic, antimony and silicon. The noble (inert) gases from the fourth category of elements.
The majority of the elements known to us are metals.For example gold, silver, platinum, copper, iron aluminium, tin, nickel chromium, mercury, calcium, magnesium, lithium, sodium, potassium, zinc, and many more.
The prime necessities of human being are food, clothing and shelter. We need heat energy to cook our food and other kinds of energy to run machines for manufacturing articles of clothing and shelter. We use various materials to fulfill our energy requirements which may be either natural or man made (i.e. artificial). We use the resources of the earth in several other ways also.
Plants and animals are living natural resources while air, water and soil are non-living natural resources. Fuel is a substance that can be used to produce heat at a reasonable cost. Today fuels have become indispensable to man. Fuels are stores of energy which on burning give heat and light mainly made up with carbon or its compounds.
NCERT textbook of class 8 science consists of all the details required to understand Conservation of Plants and Animals in this chapter with an adequate number of solved example and colorful diagram. This chapter is important for your class 8 Final exam so must be prepared very well with proper notes and mentioning all important points.
The history of biology traces the study of the living world from ancient to modern times. Although the concept of biology as a single coherent field arose in the 19th century, the biological sciences emerged from traditions of medicine and natural history reaching back to ayurveda, ancient Egyptian medicine. Cell form the basis of all living things. They are the smallest single unit of life, from the simplest bacteria to blue whales and giant redwood trees.
Differences in the structure of cells and the way that they carry out their internal mechanisms for the basis of the first measure division of life, into the three kingdoms of Archaea (ancient bacteria, Eubacteria (modern bacteria) and Eukaryota (everything else, including us). An understanding of cell is therefore vital in any understanding of life itself.Cell biology (formerly cytology, from the Greek ketos, "contain") is a scientific discipline that studies cells – their physiological properties, their structure, the organelles they contain, interactions with their environment, their life cycle, division and death.
This is done both on a microscopic and molecular level. Cell biology research encompasses both the great diversity of single-celled organisms like bacteria and protozoa, as well as the many specialized cells in multicellular organisms such as humans, plants, and sponges.Knowing the components of cells and how cells work is fundamental to all biological sciences. Appreciating the similarities and differences between cell types is particularly important to the fields of cell and molecular biology as well as to biomedical fields such as cancer research and developmental biology.
These fundamental similarities and differences provide a unifying theme, sometimes allowing the principles learned from studying one cell type to be extrapolated and generalized to other cell types. Therefore, research in cell biology is closely related to genetics, biochemistry, molecular biology, immunology, and developmental biology.
The production of new organisms from the existing organism of the same species is known as reproduction. Reproduction is the creation of new living beings. (From existing living beings)It involves the transmission of genetic material from the parental generation to the next generation. Process of reproduction is essential for existence and continuity of a species. Types of Reproduction There are many ways in which new organisms are produced from their parents. All the different ways of reproduction can be divided in to two main groups such as asexual and sexual
Adolescence is the period of physical and psychological development from the childhood to adult. Before this period, the gonads of both the sexes are dormant. They are stimulated by gonadotropins from the pituitary, which brings about the final maturation of the reproductive system. Puberty-This is the period of sexual maturation. Growth is a natural process. It begins from the day you are born, but upon crossing the age of or 11,there is a sudden spurt in growth that becomes noticeable.
The period of life, when the body undergoes certain noticeable changes, leading to reproductive maturity called adolescence. It begins after the age of 11 and lasts upto 8 to 19 years of age.Adolescents are also called as “teenagers” because the period covers the teens (13 to 18 or 19 years of age). The human body undergoes several changes during adolescence. These changes mark the onset of puberty. Puberty is the start of the time when a boy is biologically ready to become a father and a girl is biologically ready to become mother. It basically refers to the bodily changes of sexual maturation rather than psychological and social transition from childhood to adulthood. It generally overlaps the period of puberty. Puberty ends when an adolescent reaches reproductive maturity.
The pituitary gland at this stage is highly active. In addition to it, the gonads also become very active. The hormones secreted by the glands activate a series of changes which bring in physical and mental development.During adolescence, there is an increase in testosterone, changes in the ratio of excitatory and inhibitory neurotransmitters and the physical restructuring of the brain.Around the age of 20, the transmitters start to decrease and the inhibitory transmitters start to increase.
Thus, more adult-like personality traits emerge.Changes at Puberty: Increase in Height-At this stage, the physical development takes place at a rapid pace. Specially at the age of 13 in girls and 15 in boys, the development of height is the maximum.At this time the long bones, that is the bone of the arms and the legs elongate and make a person tall. By about 18 years of age, both girls and boys reach their maximum height. The rate of growth in height varies in different individuals. Some may grow suddenly at puberty and then slow down, while others may grow gradually. All parts of the body do not grow at same rate.
Let us recall some of our everyday experiences. What do we do to open or close the door of our home, to make a football move, to make a moving ball move faster? How does a goalkeeper stop a ball?
Why school bags have wide straps? Why a sharp knife cuts better than a blunt knife? Why a nail has a pointed tip? Why do buildings have wide foundations? Why the rear wheels of tractors are made very wide?
In day to day life, we observe that some effort is required to put a stationary object into motion or to stop it. So, to produce motion, the effort which is required is called as “Force”.
In this chapter, we will study about different concepts that revolve around “Force and pressure”.you will learn Force, contact and non-contact forces, a force of friction, pressure, pressure exerted by liquid and gases, and atmospheric pressure.
On the atomic scale, even the most finely polished surface like steel is irregular, such a surface can look plane to naked eyes but if seen under a powerful microscope, its surface is found to be quite irregular. When two surfaces are in contact, the actual area of contact is much less than apparent area of contact.In a particular case this area can easily be in ratios of 1:104.At points of contact, the distance between the particles of the two bodies becomes very small and their molecules exert very strong intermolecular forces of adhesion on each other.As the actual area of contact is very small, the adhesive pressure at the point of contact becomes very large.
Therefore many of the contact points may deform plastically.At these contact points, molecular bonds are formed and these points become cold welded together.When one body tens to move over the other, it involves rupturing of thousand of such tiny cold welds.The cold welds continually reform as new contacts are made.This gives rise to frictional force which resists the motion of one body over the other.
Laws of Friction: Friction can be operate between given pair of solids, between a solid and a fluid or between a pair of fluids.But frictional force exerted by fluids is called viscous force.
Friction can be classified on a basic of law of inertia.When two solid bodies slip over each other, the force of friction is called kinetic friction.But when two bodies do not slip on each other, the force of friction is called static friction.
“Frictional force applied on a body is directly proportional to the normal force acting between the two bodies.
Sound is a form of energy which makes us hear and travels in the form of waves. Sound is produced by various sources. Though sound is mechanical in nature, its perception is, of course, largely physiological.
PRODUCTION OF SOUND: When you clap your hands, a sound is produced. In order to know how sound is produced, let us perform the following two simple experiments.
Experiment 1: Stretch a metallic wire AB between two nails fixed on a table as shown in the figure. When we pluck the wire a sound is heard. If a V-shaped small paper rider (R) is placed near the centre of the wire, it starts vibrating. If the rider is placed at the centre of the wire, it flies off.
Experiment 2: On striking a bell B with a hammer, it produces sound. On touching it with finger, we feel that the bell is in a state of vibration. A pith-ball, P, suspended near the bell moves from its equilibrium position P to P as shown in figure.
In the above activities, we have produced sound by plucking and striking. We can also produce sound by scratching, rubbing, blowing, shaking, etc
Thus, we conclude that sound is produced by setting the objects in vibration. Vibration means a kind of rapid to and fro motion of an object.
PROPAGATION OF SOUND
The sound produced by vibrating objects reaches the listener only when it passes through a medium which may be a liquid, a solid or a gas. Let us now briefly discuss as to how sound travels from the source point of generation to the listener.
Light is a form of energy. More specifically, light is a general term commonly used to refer to the "visible spectrum", which is the range of wavelengths, (and their corresponding frequencies) that forms the visible part of the electro-magnetic spectrum. The ranges in wavelengths vary from 380 nm to 750 nm. Each wavelength corresponds to light of one particular colour so the "visible spectrum" range of wavelengths would look something like the block below if each wavelength appeared only once and they were all lined-up in order of increasing wavelength
The term "visible spectrum" means the range of electro-magnetic energy that most people (i.e. those with "normal" vision) can see with the naked eye. This is just a small part of a much wider range of energies, many of which we cannot see but some of which are used in other ways, e.g. Radio Waves, Microwaves, Ultra Violet (UV) Light, Infra-Red (IR) Radiation, X-Rays, and other wavelengths such as those used in many different types of modern scanning equipment.
"White Light" is the way humans perceive and refer to our experience of receiving an approx. equal quantity of all the wavelengths (i.e. colours) in the visible spectrum. This explains why there are so many different "shades of white".
That is, when we see "white" we are receiving all the colors in approximately equal amounts - but only approximately.
The combination of wavelengths (colors) received by our eyes usually contains a bit more of some than of others, hence some "whites" can appear to be slightly "yellow", some slightly "blue", and so on.
Just as white is not a "spectral color", neither is black or grey. White is the way we perceive an approx. equal presence of all colours and black is the absence of light/colour such that all colours/wavelengths are (equally) lacking. Shades of grey also correspond to approximately the same amount of each colour, but in decreasing amounts along a scale from white (lots of "light" energy in the form of many different wavelengths, corresponding to different "colors", reaching the eye/brain) to black (no "light" energy, that is an imperceptibly small quantity of "light" energy in the form of many different wavelengths corresponding to different "colors" reaching the eye/brain).
In this chapter, you will study galaxies, constellations, planets, and many more things.
GALAXY- A galaxy is a vast collection of stars, nebulae, and interstellar material held together by gravity. Nebula is a cloud of dust and gas inside a galaxy, in which a star is born.The smallest galaxies contain about 100,000 stars, while the largest contain up to 3,000 billion stars. On the basis of shape, galaxies are classified as irregular, spiral, and elliptical.E.g.:(a) Irregular galaxy (b) Spiral galaxy (c) Elliptical galaxy
MILKY WAY GALAXY- We belong to a spiral-shaped galaxy called the Milky Way galaxy. When you look up at the night sky, you can see a broad band of light in the sky. This is formed by millions of faint stars that together form the Milky way galaxy.LIGHT YEAR:Astronomers often measure distances in space in light years. A light year is the distance travelled by light in one year.
CONSTELLATION- When you look at stars on a clear night, you can see some groups of stars forming recognizable patterns. Such group of stars forming recognizable patterns in the sky is called constellations. These are named after animals and mythological characters.There are 88 constellations known so far. When any new star is discovered, it is considered to be a part of the constellation it is closer to. Some constellations that you can easily identify with the naked eye are Ursa Major, Ursa Minor, and Orion.
URSA MAJOR- This constellation consists of many stars arranged in a pattern resembling a bear.Out of these stars, a group of seven stars constitute the brightest and the most recognizable part of the Ursa Major. This group of seven stars is called the Big Dipper or Vrihat Saptarishi. If these seven stars are joined with imaginary lines, the figure obtained looks like a spoon with a long handle
Environmental pollution, solid, water & air pollution; chemical reactions in atmosphere, kind of smog major atmospheric pollutant, acid rain, ozone and its reactions, effects of the depletion of ozone layer, greenhouse effect & global warming, industrial and air pollution, pollutants, green chemistry as an alternative tool for reducing pollution. The population is defined as a group of organisms of the same species living in a geographically localised area and capable of interbreeding among themselves.
In the entire universe, only planet earth has the unique gift of being endowed with a wide variety of flora and fauna. This existence of life on the earth’s surface can be attributed to various factors among which the abundant availability of water and air on earth is the most important. The most common occurrence of water in liquid state, the easy inter-conversion of this substance into different physical states and its characteristic as a universal solvent and many other special features of this chemical substance.
Air is a mixture of several gases. Water vapor and fine dust particles. A human being respires about 22,000 times every day and takes in about 16kg of air.Air contains mainly nitrogen, Oxygen and smaller amounts of argon, carbon dioxide, water vapors and traces of helium, neon, krypton, and xenon.
Q1. What is the best approach to use NCERT solutions for class 8 Science?
Ans. Always remember that NCERT solutions are uploaded to give you a reference not to be used to copy it. It is highly recommended to solve all questions given in the exercise by the help of chapter notes that you have prepared just to check whether your answer need any modification, or if you have missed some points use NCERT solutions.
Q2. How to score full marks in Class 8 Science?
Ans. To score good marks in class 8 science start with first chapter of NCERT and try to prepare effective notes of that. Never miss your class 8 science class and make your notes effective . try to understand the concepts use in the chapter with the help of solved example and notes. Interact with your teacher to build your foundation strong. Solve all questions given in NCERT textbook and solve additional questions too from Physics Wallah class 8 notes.
Q3. MCQ questions can help me to build my foundation?
Ans. Yes, solving MCQ questions for class 8 science will certainly help you to enhance your learning. Use Physics Wallah MCQ-based questions for class 8 science all these objective questions are uploaded with answer key and are available chapter wise.
Q4. Do we need to solve sample papers for class 8 Science?
Ans. Creatively yes sample paper for class 8 science is one the best way to do entire revision of the class 8 science. The quality of questions, it helps you to identify your mistakes and improve your speed and accuracy too.
Q5. Is it the right time to start preparing for competitive exams ?
Ans. When you are in class 8 the syllabus pressure is relatively very less as compared to higher classes so for effective utilization of time one must start solving the MCQ-based questions and do beyond the NCERT text book to enhance your academic requirement. Prepare for Olympiad exam will help you to achieve your goal.