CBSE Class 8 Science Syllabus

CBSE Class 8 Science:

                 This is a syllabus of elementary standard 8th in CBSE. This covers various topics such as

  1. Food
  2. Materials
  3. The world of living
  4. Moving things, people and ideas
  5. How things work?
  6. Natural Phenomena

 

  • Food:

               This covers various topics under “Food” such as crop production, basic practices in crop production, preparation of soil for cultivation, selection of seeds and sowing techniques, importance of manures and fertilizers, process of irrigation, weeding, harvesting and its importance, methods of storage of water for irrigation, food from animals, microorganisms, etc.

Generally, Agriculture is the cultivation of crops to provide food for all life forms. For such cultivation, soil must be replenished with the nourished manures and fertilizers which can help the seeds to germinate and grow into saplings. Also, enough amounts of other nutrients and water must be supplied at the regular intervals.

Irrigation:

               The proper water supply to the plants according to its type and the season is called as irrigation. There are two types of irrigation such as Traditional irrigation and modern irrigation. Traditional irrigation is the standard method which is done with the help of human labors and animals. This is one of the cheapest irrigation methods which are done with the help of chain pump, moat and rahat. Modern irrigation method is a modern method of supplying water to the crops at the regular interval. This requires solar power or bio gas to automatically sprinkle water to the crops without any wastage.

How to protect the crop?

                Crops are prone to the attacks of pests and insects. Thus, it is necessary to take required steps to protect the crop at the right time. Insects are the six leg organisms which cause heavy loss to the crops whereas pests are the organisms which cause diseases in crop plants. These can be controlled by spraying insecticides and pesticides which can prevent crops from such pests and insects.

Weeding:

   The process of removing waste plants is called as weeding. Weeds If present always compete with the healthy crops in obtaining water, sunlight and nutrients. Thus, it is necessary to remove the weeds or unnecessary crops. Weeding can either be done manually by using harrow before they produce flowers and seeds or it can be tilled along with the soil to kill them. Weeds can also be destroyed by using weedicides which are poisonous to the human beings.

Harvesting:

           The process of cutting the mature crop to gather the grains is called as harvesting. This can either be done manually by using a sickle or using a harvestor.

Threshing:

           It is the process of separating the grains from the straw and chaff. A machine called thresher is used for this purpose.

Winnowing:

         It is the process of natural wind to flow through the grains so that the lighter substances fly away allowing heavier substance falling to the ground.

Animal Husbandry:

                           Breeding and rearing living organisms like cow, goat for the food and other products from them. For example dairy products, poultry farming, pisiculture, sericulture, piggery, etc.,

       Examples:

  1. Give two examples for each type of crops:
  • Kharif crop:
  • Rabi crop:

             Answer:

  • Maize and paddy
  • Wheat and pea
  1. Name the microorganism which can fix the atmospheric nitrogen in the soil.

Answer: Rhizobium, azatobactor, Blue green algae, etc.

 

  • Materials:

       This covers various topics such as Synthetic fibers and plastics, metals and non metals, coal and petroleum, combustion and flame, etc.

Synthetic fibers and plastics:

           There are different types of fibers available such natural and synthetic fibers. Cotton is a natural fiber which is obtained from the cotton plant whereas synthetic fibers are the man-made fibers which are prepared by the many raw materials such as petrochemicals. Synthetic fibers are made up of many small units which combine to form large unit called as a polymer. Plastics are the polymers which consist of very long molecules each composed of carbon atoms linked in chains.

Metals and non-metals:

       Metals are hard, strong and durable which is made used in many machineries, trains, automobiles, aeroplanes, water boiler, etc., However not all metals are hard and strong. Sodium and potassium are soft metals which can be cut with a knife whereas mercury is a liquid. Metals are very good conductors of heat. Non metals exist in three states such as solids, liquids and gas. Non metals do not conduct electricity and heat except graphite.

Coal and petroleum:

                   Animals and plants are drifted down to the earth after their death and decomposed to form peat. Coal was formed due to the compression of peat at high temperature and pressure. Coal is the world’s most abundant fossil fuel. Petroleum is formed from the compressed organic matter which is a dark and oily liquid with an unpleasant odour. As petroleum is lighter than that of water, the deposits of petroleum occur above the water level.

Combustion and flame:

   Combustion is a chemical process which gives off heat when reacting with oxygen. Such substances are called as combustible substances. Example of such substances are LPG, Kerosene, petrol, etc. There are three types of combustion such as rapid combustion, spontaneous combustion and explosion. The substances which vaporizes while burning produced flames. Kerosene oil and molten wax are the substances that give flame while burning. There are two types of flames such as luminous flames and non-luminous flames.

Examples:

  1. Name the petroleum product which can surface the road.

Answer: Bitumen

  1. List the conditions under which combustion can take place?

Answer: Inflammable substance, ignition temperature and Air

  • The world of living:

           These covers the topics such as conservation of plants and animals, cell structure and functions, reproduction in animals, etc.

Conservation of plants and animals:

          Conservation of forest refers to the prevention and maintenance of animals and plants species and protecting them from various threats. Forest can be conserved by maintaining biosphere reserves, wild life sanctuaries, national and zoological parks and botanical gardens.

Cell structure and function:

                     Cell is a structural and functional unit of all living organisms. Every cell in the body is meant to have some basic function. For example, alveolar is an example of single cell. A group of cells which combine to perform similar function is said to be a tissue. A structure of the cell is made up of cell wall, cell membrane, cytoplasm, and the cell organelles.

Cell wall:

               This is present in the structure of a plant cell which gives basic strength and rigidity to the plant body and stands erect during all environmental conditions.

Cell membrane:

           This is a biological membrane which separates interior of the cells from the outside environment.

Cytoplasm:

         It is a jelly like fluid which is present between the nucleus and cell membrane. Cytoplasm is a site of protein synthesis. Almost all metabolic reactions take place in cytoplasm.

Cell organelles:

       These are the living structures which float in the cytoplasm of a cell.

Reproduction in animals:

           This chapter widely covers the topics such as sexual and asexual reproduction in animals, Oviparous and viviparous animals.

Sexual and asexual reproduction in animals:

       Reproduction is a process of developing own species. This can take place in all living organisms such as humans, animals and plants. There are two types of reproduction. They are sexual and asexual reproduction.

Sexual reproduction:

               This type of reproduction involves two organisms such as male and female. Reproductive organs of female produces egg (ovum) whereas the male reproductive organs produce sperm. A zygote is the future individual formed by the fusion of egg and sperm.

Asexual Reproduction:

                 This is a type of reproduction where single parent gives rise to the offspring. Animals reproduce asexually by different process such as binary fission, budding, regeneration, cloning and fragmentation.

Oviparous and viviparous animals:

               Oviparous animals are the animals which can lay eggs. For example: Hen, Frog, Fish, etc., These types of animals undergo external fertilization.

Viviparous animals are the animals which give birth to the young ones. For example, Lion, cat and humans. These types of animals undergo internal fertilization.

Examples:

  1. A place where animals are protected in their natural habitats is called as ________

Answer: Wild life sanctuary

  1. Where does the internal fertilization occur in humans?

Answer: Female body

 

  • Moving things, ideas and people:

    This chapter covers various topics such as force, pressure, friction and sound. Let’s check one by one.

Force:

           An interaction of one object with the other object results in force between two objects. Force has both magnitude and direction. The SI unit of force is Newton.

Pressure:

          Thrust which is a force acted on an object (perpendicular to its surface) acting per unit surface area is called as pressure. The SI unit of pressure is Newton per square meter. (N/m2).

Friction:

   Friction is a type of force which opposes the relative motion between two surfaces of objects in contact.

Sound:

       Sound is a form of energy which causes sensation of hearing. Sound can be heard from all possible objects around us. They are produced from the vibrations caused in the object.

Examples:

  1. Give an example of a situation in which applied force causes a change in the shape of an object.

Answer: Inflated balloon

  1. Sound can travel through _______

Answer: Air, liquids and solids

 

  • How things work?

           This chapter covers topics such as conductivity of liquids and chemical effect of electric current.

Conductivity of liquids:

         Materials through which electric current can pass is called as conductors. Those materials which pass electric current through them are called as good conductors of electricity whereas those materials which do not allow electric current to pass through them are called as bad conductor of electricity.

          Pure water or distilled water is a poor conductor of electricity but if any impurities present in the water, it turns to good conductor of electricity.

Chemical effect of electric current:

           When an electric current is passed through a conducting solution chemical reactions are formed. This is known as chemical effect of electric current. Examples of chemical effects of electric current are:

  • Formation of bubbles of gas on the electrodes
  • Change in the color of solutions
  • Deposition of metals in electrodes

Examples:

  1. When the free ends of the tester are dipped into the solution, the magnetic needle shows the deflection. Why is it so?

Answer: It is because the solution conducts electricity and the solution plays the rule of the cell.

  1. Which of the following cannot be easily charged by friction?
  • A plastic scale
  • A woolen cloth
  • An inflated balloon
  • A Copper rod

 Answer: A copper rod

 

  • Natural Phenomena:

This covers the topic such as Lighting, protection from lightning, earthquakes, etc.,

Lightning:

         Lightning is occurred when friction occurs between water and droplets found in the atmosphere. In other words, lightning is cause due to the heavy electric discharge from the clouds to the earth.

 

Earthquakes:

             A sudden violent shaking of the ground which causes great disaster to the earth.

Examples:

  1. Which of the following is not a green gas?
  • Carbon dioxide
  • Sulphur dioxide
  • Nitrogen
  • Methane

Answer: Sulphur dioxide

  1. State the laws of reflection?

Answer: The angle of incident is equal to the angle of reflection. The ray of incidence, the ray of reflection and the normal point of incidence lie in the same plane.

Thus, the above are the topics which are covered under the CBSE Class 8 Science.

 

CBSE Class 8 Mathematics Syllabus

CBSE Class 8 Mathematics:

              Just like other CBSE classes, Class 8 has its unique way of structure of syllabus which helps student to understand the topics better. Since the syllabus are designed by the expert teachers, it is always easy for the students at the level of class 8 to understand their topics better.

Lets check out the syllabus of CBSE Class 8 Mathematics below:

 

  • Numbers:

       The chapter “Numbers” covers the syllabus just as that of the previous classes. It includes all basic and important features of “numbers” such as Exponent and powers, rational numbers, even and odd numbers, playing with numbers and factorization. Among this, the newest topics which are added for the CBSE Class 8 level are Square and square root, cube and cube root, playing with numbers, etc.,

Rational numbers:

                 Rational numbers are the numbers which can be expressed in the form of quotient or fraction of two integers. A number is generally said to be a rational number if the numbers in the fraction (for ex) p/q are integers and q is not equal to zero it is said to be a rational number. In other words, it is also expressed as a ratio between two numbers.

Exponents and powers:

                 Exponent can be defined as number of times a number multiplied by itself. Exponents can be expressed as XY where x is a number and y is the power or exponent.

For example, 24 = 2 * 2 * 2 * 2

Squares and square roots:

                 This can be explained as the number raised to the power of 2. In other words, when we multiply a number by itself it is said to be a square of a number. Similarly, a square root of a number x can be explained as the value which when multiplied by itself gives the number x.

For example, 2 is the square root of 4.

Cubes and cube roots:

                 Just like the square root of a number, we can also find out the cube root of a number by just raising the number to the power 3. In other words, the cube root of a number x when multiplied by itself 3 times we get the number x. The topics which are covered under this chapter are Finding the cube of a number, finding cube root of a perfect cubes, cube roots of perfect integers, cube roots of product of integers, cube roots of rational numbers, etc.,

Example for a cube root of 27 = 3 * 3 *3

Playing with numbers:

                This is a chapter which is a fun to solve. This includes topics like finding the patterns of a number, properties and divisibility of a number, a number is said to be divisible by another number when the remainder is zero and so on. Interesting topics which are covered under this chapter are playing Sudoku, magic squares, puzzles, interchanging digits of a number, cryptograms and so on.

        Examples:

  1. Find the multiplicative inverse of 25?

Answer: 1/25

  1. What will be the number of zeroes in the square of 5000?

Answer: 6

  1. Find the square of 39?

Answer: 1521

  1. Find the cube root of 175616.

Answer: 56

  1. What is the rational number that does not have a reciprocal?

Answer: 0

 

  • Algebra:

             A collection of symbols and numbers in an equation and solving them together is called as Algebra. Lot of introduction on Algebra is given in the previous classes and thus in the class 8, advanced concepts like division of algebraic expressions, solving linear equations, etc., are covered.

Identities in Algebra:

               One of the newest topics which has been added in the class 8 is “Identities” of algebra. There are three identities namely

  • Identity 1: Multiplication of monomials
  • Identity 2: Multiplication of a monomial and binomial
  • Identity 3: Multiplication of two binomials

         The other topics which are covered under this chapter are knowing the difference between an equation and identity, multiplication of monomials and polynomials, multiplication of binomials and monomials, etc.,

Factorization:

             Factorization is a process of splitting up an algebraic expression into one or more     factors. Topics which are covered under this are common factors and greatest common factor of monomials, factorization of binomial common factor, factorization of grouping the terms, etc.,

Division of algebraic expression:

                     This covers different topics like division of a monomial with same monomial number, division of polynomial with binomial number, division of polynomial with one variable and division of polynomial by using factorization.

Linear equations:

                         This topic covers introduction to the linear equation, solving linear equation with one variable, finding root of an equation, application and solution of a linear equation, cross multiplication method for solving equations, etc.,

 

Examples:

  1. Solve -36y3 % 9y2 = __

Answer: -4y

  1. In the expression which have the factors of the type (x+a)(x+b), remember the numerical term gives _______

Answer: ab

  1. Which of the following is the monomial?
  • 2x+7
  • 4x +y
  • 3a
  • 3x+5y+7

   Answer: 3a

 

  • Ratio and proportion:

Little advanced problems in ratio and proportion chapter are introduced in class 8. Problems on profit and loss, percentage, discount tax and overhead expenses are covered in this chapter. Other topics which are covered as calculating simple and compound interest, direct variation, inverse variation, time and work problems, etc.

Simple and compound interest:

                     Simple interest means interest calculated on certain amount of money borrowed in a specific period of time. The borrower of the money has to pay back the original principal amount plus the interest amount. It is usually for shorter periods. Compound interest is usually calculated for longer periods. Compound interest is an interest that is added to the principal amount after a specified time period and then the interest is calculated for that new principal amount.

Direct and inverse proportions:

               In a ratio of x:y, if y increases when x increases it is said to be direct proportion whereas y decreases when x increases it is said to be inverse proportion.

Time and work:

                 This is rather an important topic which mainly divided into two variations such as direct and indirect variations. Two variables are said to be “directly variable” if increase in one quantity leads to the corresponding increase in the other quantity. Two variables are said to be “indirectly variable” if increase in one quantity leads to the corresponding decrease in the other quantity.

Examples:

  1. Find the ratio of Rs.6 to 50 paise.

Answer: 12:1

  1. ________ means comparing two quantities.

Answer: Ratio

  1. Write the expression using the exponents: 25 * 25* 25

Answer: 253

  1. The cost of 5 metres of a satin cloth is Rs.210. Find the sot of 15 metres of same type of cloth.

Answer: Rs.630

  1. If 15 workers can build a wall in 48 hours, how many workers are required to do the same work in 30 hours.

Answer: 24

 

  • Geometry:

         As this has become important chapter in the previous classes of CBSE, class 8 covers more important topics under Geometry. This covers various topics like understanding the shapes, properties of different objects like polygon, parallelogram, quadrilateral, etc.,

Understanding polygons:

             A polygon is a closed figure formed by the line segments. There are different types of polygons such as Convex polygon, concave polygon and regular polygon.          

Understanding Quadrilaterals:

           Quadrilateral is a polygon with four sides and four vertices. Examples of polygons are squares, rhombus and trapezium.

Representing 3 dimensional objects in 2 D:

                 This covers various topics such as drawing 2 D objects in 3 Dimensional form, counting vertices, edges, faces and verifying Euler’s relations, etc.,

Examples:

  1. A two dimensional shape is a ______ shape.

Answer: Plane

  1. How many edges are there in a triangular pyramid?

Answer: 6

  1. State the name of the regular polygon of 4 sides.

Answer: Quadrilateral

  1. The diagonals of a _____ are perpendicular bisectors of each other.

Answer: Square

  1. State true of false for the following:
  • All squares are not parallelograms

             Answer: False

  • Mensuration:

           This is calculation of volume, area and perimeter of an object. Total boundary sizes covered by an object is said to be perimeter whereas total surface covered by an object is called as Area. Similarly, total amount of space occupied by the 3-D figure is called as volume. This chapter covers many topics like calculating volume of many 3D objects such as cubes, cuboids, prism, pyramid and others.

Examples:

  1. Find the side of a cube whose surface area is 2400 cm2.

Answer:20 cm

  1. What is the volume of a cuboid?

Answer: L *B * H

 

  • Introduction to graphs:

            Graphs concepts are introduced in this level of CBSE Class 8. Concepts such as axes, Cartesian plane, plotting points from different kinds of situation, reading off from the graphs, reading off linear graphs, reading distance vs time graphs, etc., are covered under this chapter.

Examples:

  1. On which axis does the points (5,0) lie?

Answer: X-axis

  1. In which quadrant does the point P(-8,1) lie?

Answer: IV

Thus, above topics are the syllabus of CBSE Class 8 Mathematics.