CBSE Class 9 Revision Notes

Class 9 Revision Notes

Revision notes are one of the most helpful study materials for exam preparation. Considering this fact, Extramarks is providing students with Class 9 revision notes to save time and study more effectively. Revision is an unquestionably important factor to consider when self-studying. A successful revision is crucial for good grades and academic achievement. Revision notes can also help students with last-minute preparations. 

Class 9 Revision Notes, Short Key Notes

Class 9 is a stepping stone for Class 10. Students who want to achieve good marks in Class 10 must clearly understand the concepts taught in Class 9. They can practise with NCERT notes for Class 9, which are easily available on Extramarks. In addition to the Class Notes for Class 9 and NCERT Books, students should practise important questions from the CBSE Syllabus to gain a better understanding of the concepts. 

Short keynotes will also assist students in learning and understanding concepts in less time, allowing for more efficient revision.

Class 9 Revision Notes

The following are the subjects that are covered in CBSE Class 9:

• English
• Mathematics
• Hindi
• Social Science
• Science 

CBSE Class 9 Revision Notes

Extramarks provides CBSE Class 9 Revision Notes that students can use for academic purposes. In addition to revision notes, students should also solve questions given in chapters that will aid them in better understanding and remembering the concepts.

Class 9 Revision Notes 

Extramarks provides comprehensive Class 9 Revision Notes for Science, Mathematics, Commerce, Physical Education, etc. These notes are prepared by experienced teachers in an easy-to-understand format to help students prepare for the exam without much difficulty. Download the Class 9 Revision Notes available on Extramarks to review important concepts before the exam.

CBSE Notes For Class 9

As per the current term structure announced by CBSE, it is now necessary to understand key concepts to score good marks in exams. Students can use NCERT Notes for Class 9 to understand the concepts better. The CBSE revision notes will make a significant difference to your preparation.

CBSE Class 9 Science Revision Notes 

Science is one of the most essential and high-scoring subjects for CBSE Class 9 students. With a thorough understanding of each topic covered in the Science NCERT book, students can easily answer the questions in the exam and achieve the highest possible marks. Class 9 CBSE Science Revision Notes on Extramarks can help students improve their preparation for the exam once they’ve finished the Science course.

Chapter 1: Matters in Our Surroundings 

• Anything that occupies space  and has masses is called matter. 
• Matters are made up of particles that move continuously. 
• Particles diffuse with each other to form matter. 

Chapter 2: Is matter around us pure

• Matters are made up of substances. 
• The latter will be pure if it includes pure substance. 
• Pure substance involves only a single component. 
• Metals are the elements which is a conductors of electricity and heat and possess the properties of malleability and ductility. 
• Nonmetals are the substances which do not possess the properties of metals. 

Chapter 3: Atoms and Molecules 

• Law of conversion of mass states that mass cannot be created or destroyed. 
• Law of constant proportion states that a chemical compound involves only that element which is identical to it and has the same mass. 
• Atomic theory by Dalton states that all matter is made up of atoms. 

Chapter 4: Structure of Atoms 

• Atoms constitute matter and also help in getting the structure of matter. 
• Arms involves various particles like:

1. Electron 
2. Proton
3. Neutron

• There are various atomic models

1. Thomson Model or apple pie model
2. Bohr’s model 
3. Rutherford’s model

Chapter 5: The fundamental Unit Of Life

• Cells are known as the building units of a living being. 
• There are two units of a cell, primary and structural. 
• A cell consists of plasma membrane, nucleus, and cytoplasm. 

Chapter 6: Tissues

• Tissues are of two types:

1. Plant tissues which provide mechanical strength to the plants.
2. Animal tissues which help in cell growth, and proper order of the organ system in the body. 

• Plant tissues consist of 

1. meristematic tissue 
2. simple permanent tissue
3. permanent tissue

Chapter 7: Diversity in Living Organisms

There are millions of living organisms on the earth and all of them are classified on some basis. All the organisms are divided into certain groups and sub groups. The various types of living organisms are 

• Monera
• Fungi
• Platea
• Protista
• Animalia 

Chapter 8: Motion 

An object will be in motion if its position will change from one place to another. Rest is a state where the object has zero motion. There are four types of motion:

• Rotatory 
• Vibratory
• Translatory 
• Rectilinear 

Chapter 9: Forces and Law of Motion 

Force means any external energy which changes the rest position of an object to motion in a straight path. 

There are two types of forces:

• Balanced 
• Unbalanced 

There are three laws by Newtown 

• First law which states that a body will remain in rest or motion until a thru party force will be applied. 
• Second law states that the rate of momentum is interlinked with the force which is applied on the object. 
• Third law states that actions and reactions are interrelated  to each other. 

Chapter 10: Gravitation 

• Gravitation is the type of attraction which lies between two objects in the universe. 
• It is a force which attracts a subject towards the surface of the earth. 

Chapter 11: Work and Energy 

• Work is said to be done when the applied force on an object makes it move on a straight path. 
• To carry out work, a force must he there, object should be on the same direction of the force
• It can be calculated by, 

1. W= FxS

Chapter 12: Sound 

• Sound is an energy which can be heard from our ears. 
• It requires a medium to travel. 
• It cannot travel in vacuum. 

Chapter 13: Why do we fall ill

• Health is a state of the body where it can perform physics, mental, and social activities easily. 
• A person unable to perform all these activities is considered ill. 
• There are two various types  of diseases:

1. Acute 
2. Chronic
3. Infectious 
4. Non infectious 

Chapter 14:Natural Resources 

• The substances extracted, collected by the earth are known as natural resources 
• There are three types of pollution:

1. Air 
2. Water
3. Land

Chapter 15: Improvement in Food Resources

• Improvement in food resources involves various methods

1. Improvement in crops 
2. Changing the variety of crops 
3. Deciding the quantity of crops to be produced 
4. Manure management 
5. Proper Irrigation 
6. Fertiliser management 
7. Cropping chain in the field 

Class 9 CBSE Mathematics Revision Notes

Mathematics is one of the essential subjects in school that require a lot of practice, revision, and, most importantly, attentiveness. Class 9 Mathematics revision notes on Extramarks include an overview of the sections, key concepts to remember, a quick explanation of each topic, and derivation of the formulas to better understand each chapter.

Chapter- Wise CBSE Class 9 Mathematics Revision Notes PDFs

Chapter 1: Number System Notes

1. Meaning:
2. Real and natural numbers: Real numbers, which are denoted by R, are the combination of whole numbers, integers, natural numbers, rational and irrational numbers. While natural numbers are the general counting numbers from 1. 
3. The number system involves both natural numbers and imaginary numbers. 
4. Decimal expansion of real numbers 
5. When remainder will be zero 
6. When remainder is not zero

Chapter 2: Polynomials 

1. Polynomial in one variable 

• The equations or formulas have only one variable in it.

2. Types of polynomials 

• Linear polynomial: when the polynomials are having 1° which is the greatest. 
• Zero polynomials: polynomials with zero degree.
• Quadratic polynomial: when the polynomials have the degree of 2.
• Cubic polynomials: when the polynomials have the degree of 3.

3. Factorization of polynomials

• Factorization of polynomial can be written as, dividend= Quotient × Divisor + remainder
• Methods under factorization of polynomials 
• By dividing the number or equation by the HCF obtained 
• Through identities 
• By grouping method 

Chapter 3: Coordinate Geometry 

• Coordinate Axes is the position which is determined when two perpendicular ones intersect with each other. 
• Coordinates

Chapter 4: Linear Equation in Two Variables 

• Meaning 
• Linear equation is an equation which can be expressed in the form of ca+by+z=0, in which a, b, and c are real numbers. 
• Solutions of linear equations 
• Solution of any linear equation can he find out when LHS=RHS

Chapter 5: Euclid Geometry 

• It is a geometrical approach to solve a problem. 
• There are various assumptions made under euclid theory of geometry. 

Chapter 6: Lines and Angles 

• Concepts and meaning
• Point: small dot which does not have  any length or thickness or width 
• Line segment: a path that joins two points
• Collinear points: more than two or two points on a line.
• Noncollinear points: the points which don’t lie on the same line.
• Ray: a line segment that can be expanded in one path only.
• Line: a line segment that can be expanded through both directions. 
• Intersecting lines: two lines meeting at one point in common. 
• Plane: a platform where a point lies that connects any of the two points on the line. 
• Concurrent lines: when two or more lines meet at the same point
• Angels: formed when two straight lines meet at one point in common.

Chapter 7: Triangles 

• Congruent geometric figures 
• Meaning: The figures have identical shapes and size are congruent figures 
• Congruent triangles 
• Meaning: triangles with identical shape and size are the congruent triangles 
• Definition: two triangles are said to be congruent one of it’s sides are equal and same to the other side. 
• Congruent circles 
• Meaning: circles with same radius are the congruent circles 

Chapter 8: Quadrilaterals 

• Meaning 
• A polygon with four sides 
• Parallelogram have all equal and same sides like rectangle, square 
• Trapezium have the opposite sides equal 

Chapter 9: Areas of parallelogram and triangles 

• Triangle 
• Meaning: a figure having three lines, two dimensions, and three corners 
• Parallelogram 
• Meaning: A figure having the opposite sides equal. 

Chapter 10: Circles 

1. Meaning:

•  A locus of all the points in a plane fixed from a distance. 

2. Sector 

• Area or distance between two radii and arc. 

3. Chord

• A straight line connecting two points in a plane

4. Circumference 

• Length of a circle, parameter

5. Arc

• A part of the circumference 

Chapter 11: Construction 

• It is a process of making a geometrical figures using a ruler and a compass
• This mainly involves the construction of two figures, 
• Basic construction of bisector 
• Construction of triangle 

Chapter 12: Herons Formula 

• Area of triangle when height is given 
• ½×base×height 
• Area of triangle under heron’s formula
• √s(s-a)(s-b)(s-c) 
• Area of triangle through area of quadrilateral 
• Divide the quadrilateral into two parts which forms two triangles 

Chapter 13: Surface Area and Volume 

• Cuboid 
• Surface area : 2(lb+bh+hl)
• Volume: lxbxh 
• Cube 
• Surface area= 6l²
• Volume= l³
• Right circular cone
• Surface area
• CSA= πrl
• TSA= πr(r+l)
• Volume= 1/3πr²h 
• Cylinder 
• Surface area 
• CSA= 2πrh
• TSA= 2πr(r+h) 
• Volume= πr²h
• Sphere 
• Surface area= 4πr²
• Volume = 4/3 πr³
• Spherical shell 
• Surface area= 4πR²
• Volume= 4/3π(R³-r³)
• Hemisphere 
• Surface area 
• CSA= 2πr²
• TSA= 3πr²

Chapter 14: Statistics 

• Statistics can be used to collect data in cardinal or numeric forms. 
• These data can be used to find solution to some questions 
• There are two types of data, primary and secondary

Chapter 15: Probability 

• Probability means making an estimation regarding something. 
• These values are approximations and not the exact numbers. 
• Probability uses various tools like trail, randomness, events, impossible events, random events , and elementary events. 

Benefits of CBSE Notes of Class 9 By Extramarks

Studying with revision notes for Class 9 prepared by the Extramarks team can benefit you in a number of ways. Listed below are a few of them: 

• The revision notes will assist you to sort your learning.
• They will help you to identify the important topics to study for the exams.
• They will help students remember important concepts, facts, figures and procedures that have been studied so far.
• Students who refer to these revision notes are likely to score well in their upcoming Class 9 exams.
• The well-prepared notes will also help to increase students’ confidence before the exam.