CBSE Syllabus for Class 8 Science for Academic Year 2021-2022
Familiarizing oneself with the CBSE Class 8 Science syllabus is crucial for students who are preparing for their exams. The syllabus covers a range of topics and serves as a guide for students to structure their studies effectively.
It provides a comprehensive overview of what will be covered during the academic year 2021-2022, helping students to plan their studies and focus on important concepts. Understanding the CBSE syllabus for Class 8 Science is essential for students to perform well in their exams and achieve academic success.
It is important for students to refer to the syllabus each time they study, as it can aid in developing a deeper understanding of the syllabus and the topics that require their focus. By referring to the syllabus regularly, students can stay on track with their studies, identify the key concepts they need to grasp, and prioritize their learning accordingly.
The syllabus serves as a guide for students, providing them with a roadmap to structure their studies effectively. Thus, it is essential for students to consult the syllabus throughout their academic journey to perform well in their exams and achieve success.
Download CBSE Class 8 Science Syllabus PDF for 2020-2021
Chapter 1: Crop Production and Management
Chapter 2: Microorganisms : Friend and Foe
Chapter 3: Synthetic Fibres and Plastics
Chapter 4: Materials – Metals and Non-Metals
Chapter 5: Coal and Petroleum
Chapter 6: Combustion and Flame
Chapter 7: Conservation of Plants and Animals
Chapter 8: Cell – Structure and Functions
Chapter 9: Reproduction in Animals
Chapter 10: Reaching the Age of Adolescence
Chapter 11: Force and Pressure
Chapter 12: Friction
Chapter 13: Sound
Chapter 14: Chemical Effects of Electric Current
Chapter 15: Some Natural Phenomena
Chapter 16: Light
Chapter 17: Stars and The Solar System
Chapter 18: Pollution of Air and Water
Chapter 1: Crop Production and Management – Class 8 – Notes
Agriculture is a vital sector of the Indian economy, and crops are the primary plants cultivated by farmers. In fact, it is often considered the backbone of the country, supporting the livelihoods of 70% of the population who depend on it for both food and income.
The cultivation of crops is a major occupation in rural areas and is heavily influenced by the prevailing weather patterns and soil conditions. These factors play a crucial role in determining the success of crop yields and, in turn, impact the overall agricultural output of the country.
Chapter 2: Microorganisms : Friend and Foe – Class 8 – Notes
If one were to observe a drop of water from a pond through a microscope, they would notice the presence of numerous tiny, rounded structures. These structures, which are invisible to the naked eye, are known as microorganisms or microbes.
Microbes are ubiquitous and can be found in various environments, ranging from soil to water bodies, and even within living organisms. These tiny organisms are classified into four main groups:
- Bacteria – single-celled, prokaryotic organisms that play a vital role in various ecological processes, including nutrient cycling and decomposition.
- Protozoa – unicellular, eukaryotic organisms that are mostly found in aquatic environments and play a crucial role in the food web.
- Fungi – eukaryotic organisms that are primarily decomposers and play a vital role in the breakdown of dead organic matter.
- Algae – photosynthetic eukaryotic organisms that are mostly aquatic and are the primary producers in aquatic ecosystems.
These four groups of microorganisms play a critical role in maintaining the balance of various ecosystems and are crucial for the survival of life on Earth.
Chapter 3: Synthetic Fibres and Plastics – Class 8 – Notes
Clothing is an essential aspect of our daily lives, and we wear a variety of clothes for different purposes. Some clothing items are worn for special occasions, while others are season-based and are chosen for their ability to provide comfort and protection from the weather.
All types of clothing are made from fibers, which are the basic building blocks of textiles. Fibers can be natural, such as cotton, wool, silk, or flax, or synthetic, such as polyester, nylon, and rayon.
During the summer season, people typically prefer clothing made from lightweight, breathable natural fibers such as cotton, which helps to keep them cool and comfortable in the heat. In contrast, during the winter season, people tend to wear clothing made from thick, warm materials such as wool, which provides insulation and helps to keep them warm.
Similarly, during the rainy season, people often wear raincoats made from waterproof synthetic fibers that protect them from the rain.
Chapter 4: Materials – Metals and Non-Metals – Class 8 – Notes
Metals and non-metals are two fundamental categories that classify the vast array of materials that surround us. Understanding the properties and characteristics of these categories is essential to distinguish between them and appreciate their diverse applications in different fields.
Chapter 4 of Class 8 Science provides a comprehensive overview of the physical and chemical properties of metals and non-metals. Metals are typically lustrous, ductile, malleable, and good conductors of heat and electricity. They also tend to be dense and have high melting and boiling points. Examples of metals include copper, iron, gold, and aluminum, among others.
Chapter 5: Coal and Petroleum – Class 8 – Notes
Energy is an indispensable aspect of life and a vital resource for all living organisms. It exists in many forms and can be transferred from one body to another in various ways, such as through heat or work. The sun is the ultimate source of all energy available on Earth, either directly or indirectly.
In Physics, energy is a measurable quantity that is transferred to an object to enable it to perform work. It can be defined as the capacity to do physical activity or work. One of the fundamental principles of energy is that it is a conserved quantity, and the law of conservation of energy states that energy can neither be created nor destroyed, only converted from one form to another.
The SI unit of energy is the Joule, which is a measure of the amount of work done when a force of one Newton acts over a distance of one meter. Energy can take various forms, such as mechanical energy, thermal energy, chemical energy, and electromagnetic energy, among others.
Chapter 6: Combustion and Flame – Class 8 – Notes
- Combustion refers to a chemical process where a substance reacts with oxygen to produce heat, light, and other products. This process is a crucial aspect of many natural and human-made processes, from the burning of fuels to the metabolism of food in living organisms.
- The burning of wood is a prime example of combustion, where the wood reacts with oxygen from the air to produce heat and light energy.
Combustion refers to a chemical process where a substance reacts with oxygen to produce heat, light, and other products. This process is a crucial aspect of many natural and human-made processes, from the burning of fuels to the metabolism of food in living organisms.
The burning of wood is a prime example of combustion, where the wood reacts with oxygen from the air to produce heat and light energy.
Chapter 7: Conservation of Plants and Animals – Class – 8 – Notes
- Extinction refers to the irreversible loss of a species or a group of organisms, where the last living individual of that species or group dies.
- This phenomenon is a natural part of the evolutionary process, but it has accelerated significantly due to human activities such as habitat destruction, overhunting, pollution, and climate change.
Chapter 8: Cell – Structure and Functions – Class – 8 – Notes
Cells are the smallest functional and structural units of life that form the building blocks of all living organisms. They were first observed by Robert Hooke in 1665 when he examined a thin slice of cork under a microscope he had constructed himself. He observed small, box-like structures that reminded him of the cells where monks lived, and thus, he named them “cells”.
Chapter 9: Reproduction in Animals – Class – 8 – Notes
Reproduction is a fundamental biological process by which living organisms produce offspring. It is essential for the continuity of a species and allows for genetic diversity. Reproduction occurs in all known life forms, from single-celled organisms to complex multicellular organisms.
In animals and plants, reproduction can occur through two main methods:
- Sexual Reproduction: This involves the fusion of male and female gametes, resulting in the production of offspring that possess a combination of genetic traits from both parents. Sexual reproduction leads to genetic variation, which is essential for the survival of a species.
- Asexual Reproduction: This involves the production of offspring without the fusion of gametes. A single organism can produce genetically identical offspring through various asexual reproduction methods such as budding, fission, and fragmentation.
Chapter 10: Reaching the Age of Adolescence – Class – 8 – Notes
Adolescence is a crucial period in human development that marks the transition from childhood to adulthood. It is a time of significant physical, emotional, and social changes as the body undergoes various transformations leading to reproductive maturity.
Typically, adolescence begins around the age of 11 and lasts until 18 or 19 years of age. During this period, individuals are commonly referred to as ‘teenagers.’
The physical changes that occur during adolescence are primarily driven by hormonal changes, which trigger the onset of puberty. These changes include the development of primary and secondary sexual characteristics, such as the growth of pubic and underarm hair, the deepening of the voice, and the onset of menstruation in females.
In addition to physical changes, adolescence is also a time of significant emotional and social growth. Adolescents experience heightened emotions, increased self-awareness, and a desire for independence. They also form new relationships and begin to explore their identities and values.
Chapter 11: Force and Pressure – Class – 8 – Notes
Force is a fundamental concept in science that refers to the push or pull exerted on an object. It arises from the interaction between two objects and has both magnitude and direction. The strength of a force is expressed in terms of its magnitude, which is measured in units such as Newtons (N).
Force is responsible for bringing about a change in the motion or state of an object. It can cause an object to start moving, stop moving, or change direction. The effect of force on an object is determined by the object’s mass and acceleration, which are related by Newton’s Second Law of Motion.
In class 8 Science chapter 11, various characteristics of force are discussed, including its types. Forces can be classified into different types based on their origin, such as contact forces and non-contact forces. Contact forces arise from the physical contact between two objects, while non-contact forces act at a distance without any physical contact.
Chapter 12: Friction – Class – 8 – Notes
When a ball is thrown on the floor, it starts moving with some velocity, and once it is rolled, it should ideally keep on rolling due to the absence of any force acting in the direction of motion, as per Newton’s first law.
However, in reality, the ball eventually stops moving after covering a certain distance. This happens because a force opposes the motion of the ball. This force is known as friction.
Chapter 13: Sound – Class – 8 – Notes
Sound is an essential aspect of our lives. It helps us identify the end of a school period and determine if someone is approaching us simply by listening to their footsteps. When an object vibrates, it produces sound.
Vibration is defined as the back-and-forth or to-and-fro motion of an object. For sound to travel, it requires a medium to travel through. This means that sound cannot propagate in a vacuum.
Chapter 14: Chemical Effects of Electric Current – Class – 8 – Notes
Metals like copper and aluminum have free electrons that can easily move from one atom to another and hence they are good conductors of electricity. Materials like rubber and plastic do not have free electrons, and hence they do not conduct electricity.
In the case of liquids, some liquids like saltwater, acids, and bases are good conductors of electricity, while pure water, vegetable oil, and alcohol are bad conductors of electricity. The presence of ions in a liquid determines its ability to conduct electricity. Distilled water is free from any ionic impurities and hence it is a poor conductor of electricity.
Chapter 15: Some Natural Phenomena – Class – 8 – Notes
In class 8 Science chapter 15, we study natural phenomena like lightning and earthquakes, which can cause severe damage to life and property.
Lightning is a natural electrical discharge of static electricity that occurs within a thundercloud, from the ground to the cloud, or from the cloud to the ground. Earthquakes, on the other hand, are natural disasters that occur when the earth’s tectonic plates shift, leading to the sudden release of energy.
Chapter 16: Light – Class – 8 – Notes
Our perception of the world is largely based on the information gathered through our senses, and the sense of sight is one of the most crucial among them. We are able to see objects only when light emanating from them or reflected by them enters our eyes.
Light is a form of energy that allows us to see the world around us. It can be emitted from sources such as the Sun or other artificial sources of light. The term ‘light’ generally refers to visible light, which is the portion of the electromagnetic spectrum that is visible to the human eye and is responsible for our sense of sight.
Chapter 17: Stars and The Solar System – Class – 8 – Notes
Celestial bodies refer to the planets, stars, moons, and other objects in space. Astronomy, a branch of science, is concerned with the study of these celestial bodies and their characteristics. One of the observable features of celestial bodies is the changing shape of the moon, which occurs due to its position relative to the Earth and the Sun.
When the entire illuminated portion of the moon is visible from the Earth, it is known as a full moon, while when none of it is visible, it is known as a new moon.
The different shapes of the illuminated portion of the moon that can be seen over the course of a month are referred to as phases. These phases occur because we can only see the portion of the moon that is reflecting the Sun’s light towards the Earth.
Chapter 18: Pollution of Air and Water – Class – 8 – Notes
In chapter 18 of class 8 Science, we learn about the harmful changes occurring in our environment and their impact on our health. Substances that contaminate the air and water are called pollutants. Natural sources such as forest fires or volcanic eruptions contribute to air pollution by releasing smoke and dust.
Man-made pollutants include emissions from power plants and vehicles, as well as burning of firewood. Major air pollutants include carbon dioxide, nitrogen oxides, carbon monoxide, methane and sulphur dioxide.
Increased levels of carbon dioxide contribute to global warming, which has significant environmental consequences. This is part of the CBSE Syllabus for Class 8 Science for the academic year 2020-2021.
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