NCERT Solutions for Class 9 Science

NCERT - Science

NCERT Solutions for Class 9 Science have been made available here in a detailed format to assist students master the subject. Science is one of the toughest and the most important subjects of CBSE Class 9th. Therefore, to score good marks in Science subject, it is important to understand and learn the fundamental concepts first and foremost. Science is not at all a theoretical subject and thus it gets vital to practise the concepts properly. 

More than often, students commit the common mistake of referring to the 'extra' books rather than studying from the NCERT Solutions. It is always advisable to first complete the NCERT Class 9 Science book and then jump into the reference books for the exam preparation. Below you can check chapter-wise NCERT Class 9 Science Solutions.  

NCERT Class 9 Science Solutions - All Chapters

The best approach to prepare for the CBSE Class 9 Science subject is to use NCERT Solutions of Science textbook. The experienced mentors of Goprep have provided chapter-wise, comprehensive NCERT Solution for Class 9 Science of all the chapters. The solutions are made on the basis of the latest syllabus of Science subject. We have listed the NCERT Solution for Class 9 Science for all the 15 chapters above.

NCERT Solutions for Class 9 Science (Chapter-wise Description)

Chapter 1: Matter in Our Surroundings

Introduction: In this chapter, you will learn that matter is made of tiny particles, which, as a whole, has mass and occupy space. There are three states of matter- Solid, Liquid and Gas. Their particles possess kinetic energy due to which they move continuously.

In solids, the movement is minimal as compared to liquids and gases as it has the maximum intermolecular force of attraction in comparison to liquid and gas. 

 One can also spot differences between them by the property of rigidity in case of solids and fluidity in case of liquids and gases. The states of matter are interconvertible. Pressure and temperature are two factors responsible for changing the state of matter.

Processes carried out to change the state of matter include Sublimation (from solid to gas and gas to solid), Evaporation (liquid to gas), and Solidification (Liquid to solid).  

 Further, in this chapter, you will explore the factors affecting the rate of evaporation. The back exercise of NCERT Class 9 Science chapter-1 includes a total of 27 questions framed from the following topics. 

 List of Topics in “Matter in Our Surroundings”

  1. Physical Nature of Matter
  2. Characteristics of Particles of Matter
  3. States of Matter
  4. Can Matter Change its State?
  5. Evaporation
  6. Plasma
  7. Bose-Einstein Condensate


Chapter 2: Is Matter Around Us Pure

Introduction: In the second chapter of the NCERT Class 9 Science textbook, you will learn to differentiate solutions, suspensions and colloids. You already know that an atom is the smallest unit of matter. Pure substances are made up of similar kind of elements (group of atoms) or compounds (a group of elements). 

A solution is a homogeneous mixture while suspension and colloids are heterogeneous in nature. The fine particles of a solution can neither be seen with a microscope nor naked eyes.

On the other hand, the size of particles of suspension and colloids is comparatively larger in comparison to solutions. Due to the presence of visible particles, colloids and suspensions exhibit the Tyndall effect. 

This chapter includes 21 questions which will be based on the topics mentioned below. 

 List of Topics in “Is Matter Around Us Pure” 

  1. Mixture and its Types
  2. Solution- Its Concentration, Suspension & Colloidal Solution
  3. Separating the Components of a Mixture (Evaporation, Centrifugation, Chromatography, Distillation & Crystallization)
  4. Physical and Chemical Changes
  5. Types of Pure Substances (Elements & Compounds)


Chapter 3: Atoms and Molecules

Introduction: As discussed in earlier chapters, an atom is the smallest unit of an element that cannot usually exist independently and retain all its chemical properties. You must also be familiar with the term ‘molecule’, which is the smallest particle of an element or a compound capable of independent existence under ordinary conditions. 

Apart from these basic terminologies, the main highlights of the chapter are two laws of chemical combination. According to the law of conservation of mass, the sum of the masses of reactants and products remain unchanged during a chemical reaction.

The second law, the law of definite proportions, states that elements always exist in definite proportion by mass in a pure chemical compound. 

You will find a total of 25 solved NCERT back-exercise questions in this chapter. You must have a thorough understanding of the topics given below before you view NCERT Solutions. 

List of Topics in “Atoms and Molecules”

1. Laws of Chemical Combination

(a). Laws of Conservation of Mass

(b). Law of Constant Proportions

2. Atom

(a). Modern Day Symbols of Atoms of Different Elements

(b). Atomic Mass

(c). Existence of Atoms

3. Molecule

(a). Molecules of Elements

(b). Molecules of Compounds

(c). Ion

4. Writing Chemical Formulae

(a). Formulae of Simple Compounds

5. Molecular Mass and Mole Concept

(a). Molecular Mass

(b). Formula Unit Mass

(c). Mole Concept

Chapter 4: Structure of the Atom

Introduction: The discovery of electron and proton was made possible by J.J. Thomson and E.Goldstein, respectively. Later, Thomson also stated that electrons are embedded in a positive sphere.

Rutherford’s alpha-particle scattering experiment led to the discovery of the atomic nucleus. His model of the atom resembled the solar system where the nucleus is located at the centre while electrons revolve around it in circular orbits. 

Neil Bohr’s model of the atom received better response as he was able to explain the stability of the atom. According to him, electrons are scattered in different shells with discrete energy around the nucleus. An atom became a complete entity when J.Chadwick discovered the presence of electrons, protons and neutrons. 

 In the latter half of the chapter, you will come across important terminologies such as atomic number, mass number, isotopes and isobars. This chapter consists of 37 questions based on the concepts given below. 

List of Topics in “Structure of the Atom"

1. Charged Particles in Matter

2. The Structure of an Atom

(a). Thomson’s Model of an Atom

(b). Rutherford’s Model of an Atom

(c). Bohr’s Model of Atom

(d). Neutrons

3. How are Electrons Distributed in Different Orbits?

4. Valency

5. Atomic Number and Mass Number

(a). Atomic Number

(b). Mass Number

6. Isotopes

(a). Isobars

Chapter 5: The Fundamental Unit of Life

Introduction: Cell is the smallest structural unit of life. The plasma membrane, also known as a semipermeable membrane, encloses the contents of the cell and allow the exchange of material and gases.

This membrane is composed of lipids and proteins. It is found in both animal and plant cells while cell wall, which is an additional layer for the purpose of protection is found in plant cells only. 

Later in this chapter, you will study the differences between eukaryotic and prokaryotic cells. A eukaryotic cell is characterized by the presence of membrane-bound nucleus and cell organelles. Endoplasmic reticulum (ER), Golgi apparatus, plastids etc are some examples of cell organelles. 

To understand the composition of prokaryotic/ eukaryotic and plant/ animal cells, you must study the following topics. There are a total of 18 questions based on these concepts. 

List of Topics in “The Fundamental Unit of Life”

1. What are Living Organisms Made Up of?

2. Cell and its composition/ Structural Organization of a Cell

(a). Plasma Membrane or Cell Membrane

(b). Cell Wall

(c). Nucleus

(d). Cytoplasm

3. Cell Organelles

(a). Endoplasmic Reticulum (ER)

(b). Golgi Apparatus

(c). Lysosomes

(d). Mitochondria

(e). Plastids

(f). Vacuoles

4. Cell Division

Chapter 6: Tissues

Introduction: A tissue can be defined as a group of cells similar in appearance and function. Plant tissues are classified into two types- meristematic and permanent tissue. Meristematic tissue is found at the tips of root and stem of the plant. They have the capability to divide until the plant fully matures. Once the plant is fully-grown, they lose their ability to divide to form permanent tissue. 

Permanent tissues are divided into two types- simple permanent and complex permanent tissue. Simple tissue is further classified into two types- protective and supportive. 

Epidermis and cork are two protective tissues, which protects the plant from harsh conditions and damage. Parenchyma, collenchyma and sclerenchyma are three supportive tissues, which provides mechanical strength and flexibility to the plant. Xylem and Phloem are types of complex permanent tissues. 

List of Topics in “Tissues” 

1. Are Plants and Animals Made of Same Types of Tissues?

2. Plant Tissues

(a). Meristematic Tissue

(b). Permanent Tissue (Simple Permanent & Complex Permanent Tissue)

3. Animal Tissues

(a). Epithelial Tissue

(b). Connective Tissue

(c). Muscular Tissue

(d). Nervous Tissue

Chapter 7: Diversity in Living Organisms

Introduction: Classification helps us to study the diverse forms of living organisms. As per the five-kingdom classification system, the living organisms are classified into five kingdoms, namely Monera, Protista, Fungi, Plantae and Animalia. These organisms are classified based on the number of cells, the presence of membrane-bound nucleus and cell organelles etc. 

The plant kingdom is subdivided into five groups- Angiosperms, Bryophytes, Gymnosperms, Pteridophytes and Thallophytes.

The animal kingdom is divided into ten groups- Annelida, Arthropoda, Coelenterata, Echinodermata, Mollusca, Nematoda, Platyhelminthes, Porifera, Vertebrates and Protochordates. Scientific names are given to all these living organisms for the sake of identification. 

In this chapter, you will find a total of 23 questions in the back exercise. You must consider the topics given below before studying NCERT Solutions for Class 9 Science. 

List of Topics in “Diversity in Living Organisms”

1. The Basis of Classification

2. Classification and Evolution

3. The Hierarchy of Classification Groups

(a). Monera

(b). Protista

(c). Fungi

(d). Plantae

(e). Animalia

4. Plantae

(a). Thallophyta

(b). Bryophyta

(c). Pteridophyta

(d). Gymnosperms

(e). Angiosperms

5. Animalia

(a). Porifera

(b). Cnidaria

(c). Platyhelminthes

(d). Nematoda

(e). Annelida

(f). Arthropoda

(g). Mollusca

(h) Echinodermata

(i). Protochordata

(j). Vertebrata

6. Nomenclature 

Chapter 8: Motion

Introduction: In this chapter of the NCERT Class 9 Science textbook, you will first study the difference between motion and rest. An object is said to be in ‘motion’ when there is a change in position of an object with respect to its reference point.

When there is no change in position of an object with respect to reference point, then it is said to be at ‘rest’. 

Next, you will learn to distinguish speed/ velocity, distance/ displacement, and uniform/ non-uniform motion. You will also learn to derive three equations of motion for the object moving with uniform acceleration graphically. Finally, you will study the motion of an object travelling with uniform speed in a circular path. 

This chapter consists of 25 questions that are based on the following concepts.

List of Topics in “Motion”

1. Motion

(a). Motion Along a Straight Line

(b). Uniform Motion and Non-Uniform Motion

2. Measuring the Rate of Motion

(a). Speed with Direction

3. Rate of Change of Velocity

4. Graphical Representation of Motion

(a). Distance-Time Graphs

(b). Velocity-Time Graphs

5. Equations of Motion by Graphical Method

(a). Equation for Velocity-Time Relation

(b). Equation for Position-Time Relation

(c). Equation for Position-Velocity Relation

6. Uniform Circular Motion

Chapter 9: Force and Laws of Motion

Introduction: You have already studied ‘force’ in your earlier NCERT Science textbooks. Force can be defined as a push or a pull in a direction opposite to the friction. Force of friction always opposes the motion of objects.

Force can be classified as balanced and unbalanced. An unbalanced force can bring an object in motion to rest or rest to motion. It can also bring a change in its direction, shape and speed. 

In this chapter, you will also study Newton’s three laws of motion. According to the first law, an object continues to stay in a state of rest or uniform motion along a straight line unless an unbalanced force is acted upon it.

The second law states that the rate of change of momentum of an object  is directly proportional to the applied unbalanced force in the direction of the force. 

The third law of motion states that every action has an equal and opposite reaction. At the end of the chapter, you will find 31 questions based on the following topics. 

List of Topics in “Force and Laws of Motion”

1. Balanced and Unbalanced Forces

2. First Law of Motion

3. Inertia and Mass

4. Second Law of Motion

(a). Mathematical Formulation of the Second Law of Motion

5. Third Law of Motion

6. Conservation of Momentum

Chapter 10: Gravitation

Introduction: According to the law of gravitation, the force of attraction between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. The force of gravity decreases with altitude. It also decreases from poles to the equator. 

A free-falling object is said to be under the influence of gravitational force due to which it gets attracted towards the centre of the Earth. The weight of the body is the force with which the Earth attracts it. The weight may vary from place to place, but the mass stays constant. 

List of Topics in "Gravitation"

1. Gravitation

(a). Universal Law of Gravitation

(b). Importance of the Universal Law of Gravitation

2. Free Fall

(a). To calculate the value of g

(b). Motion of Objects under the Influence of Gravitational Force of the Earth

3. Mass

4. Weight

(a). Weight of an Object on the Moon

5. Thrust and Pressure

(a). Pressure in Fluids

(b). Buoyancy

(c). Why Objects Float or Sink When Placed on the Surface of Water?

6. Archimedes’ Principle

7. Relative Density

Chapter 11: Work and Energy

Introduction: In this chapter, we will learn that when an object covers some displacement in the direction of the applied force. This is called work done on an object. Applying this concept, there is no work done if the object has zero displacement. 

The next concept is of energy possessed by an object upon application of an unbalanced force. From the knowledge of the first chapter, you are familiar that particles of matter possess kinetic energy due to which they move continuously.

It can be said that when an object is in motion, it possesses kinetic energy. Potential energy is the energy possessed by a body due to its change in position or shape. 

On reading the entire chapter, you will cover the following topics. 

 List of Topics in "Work and Energy"

1. Work

2. Energy

(a). Forms of Energy

(b). Kinetic Energy

(c). Potential Energy

(d). Potential Energy of an Object at a Height

(e). Are Various Energy Forms Interconvertible?

(f). Law of Conservation of Energy

3. Rate of Doing Work

(a). Commercial Unit of Energy

Chapter 12: Sound

Introduction: Sound is a form of energy which travels in the form of longitudinal waves through a material medium. Due to this, it causes vibration in different objects.

In sound propagation, it is the energy of the sound that travels but not the particles of the medium. In previous classes, you have already read that sound requires a medium to travel as it cannot travel in a vacuum. 

Next, you will revisit some important terms from the previous classes, such as oscillation, wavelength, time period, frequency etc. You will also learn to determine the sound properties, such as pitch, loudness and quality.

Finally, you will study the differences between ultrasonic and infrasonic waves. To familiarise you with the topics given below, we have provided the NCERT Class 9 Science Solutions for chapter-12 above. 

List of Topics in "Sound"

1. Production of Sound

2. Propagation of Sound

(a). Sound Needs a Medium to Travel

(b). Sound Waves are Longitudinal Waves

(c). Characteristics of a Sound Wave

(d). Speed of Sound in Different Media

3. Reflection of Sound

(a). Echo

(b). Reverberation

(c). Uses of Multiple Reflection of Sound

4. Range of Hearing

5. Applications of Ultrasound

(a). SONAR

6. Structure of Human Ear

Chapter 13: Why do We Fall ill?

Introduction: In this chapter of NCERT Class 9 Science, you will read the types of diseases, causes, infectious agents, and prevention measures. A person is said to be healthy when he/she is disease-free and is in a state of physical, mental and social well-being. The types of diseases are classified as acute or chronic, depending on their duration. 

Pathogens are infectious agents or microorganisms that can cause diseases in human beings. One can catch an infectious disease through the air, water, physical contact or vectors.

To prevent such diseases, you must take public health hygiene measures. Immunization is another measure to reduce exposure to infectious agents. 

List of Topics in "Why do We Fall ill"

1. Health and its Failure

(a). The Significance of ‘Health’

(b). Personal and Community Issues 

(c). Differences between Healthy and Disease-Free

2. Disease and Its Causes

(a). What does Disease look like?

(b). Acute and Chronic Diseases

(c). Chronic Diseases and Poor Health

(d). Causes of Diseases

(e). Infectious and Non-Infectious Causes

3. Infectious Diseases

(a). Infectious Agents

(b). Means of Spread

(c). Organ-specific and Tissue-specific Manifestations

(d). Principles of Treatment

(e). Principles of Prevention

Chapter 14: Natural Resources

Introduction: The survival of living organisms on Earth depends on the presence of natural resources such as soil, water, air, and sunlight. Uneven heating of air over land and water-bodies leads to the formation of wind currents.

Evaporation of water from water-bodies and subsequent condensation leads to precipitation (rain). 

In recent times, there have been environmental disturbances in nature due to factors including global warming, pollution and soil erosion, to name a few. Sustainable development needs to be practised to improve the quality of living and protect biodiversity. 

List of Topics in "Natural Resources"

1. The Breath of Life: Air

(a). The Role of the Atmosphere in Climate Control

(b). The Movement of Air: Winds

(c). Rain

(d). Air Pollution

2. Water: A Wonder Liquid

(a). Water Pollution

3. Mineral Riches in the Soil

4. Biogeochemical Cycles

(a). The Water-Cycle

(b). The Nitrogen-Cycle

(c). The Carbon-Cycle

(d). The Oxygen-Cycle

5. Ozone Layer

Chapter 15: Improvement in Food Resources

Introduction: For optimum growth of crops, plants absorb nutrients from the soil. Nutrients that are required in large quantities are called macronutrients, whereas the remaining nutrients that are absorbed in small quantities are known as micronutrients. Manure and fertilizers support the major requirement of nutrition to crops. 

As you proceed in this chapter, you will study three methods of farming: organic farming, mixed farming and poultry farming. After completing this chapter, you will understand the following terminologies and methods. 

List of Topics in "Improvement in Food Resources"

1. Improvement in Crop Yields

(a). Crop Variety Improvement

(b). Crop Production Management

2. Animal Husbandry

(a). Cattle Farming

(b). Poultry Farming

(c). Fish Production

3. Bee-Keeping

Benefits of using NCERT Solutions for Class 9 Science

It is important to first study and complete Science NCERT textbook and then practice from other reference books if you aim to score better in the subject. There are several advantages of adding NCERT Solution for 9th Class Science to your exam preparation strategy. We have listed a few of them for you below:

  • The Goprep NCERT solutions are prepared by highly skilled and experienced subject experts
  • You will not find/spot any error or mistake in any solution
  • The solutions are prepared on the basis of the latest CBSE Class 9th Science syllabus
  • The solutions are comprehensive, accurate and very useful
  • You can clear all your doubts and also use it while preparing for the exam preparation
  • Most importantly, the NCERT Solutions for Class 9 Science prepared by Goprep experts are free of cost


Frequently Asked Questions

  • What are NCERT Solutions?

    NCERT Solutions for Class 9 is a systematic and compiled answers prepared on the basis of the most recent syllabus approved by the Central Board of Secondary Education (CBSE). The solutions are prepared by the skillful experts having huge experience about the subject. The solutions are prepared in a very easy and simple manner so that students can understand each and every point which is explained in the answer.

  • Where can I find best NCERT Solutions for Class 9 Science?

    You will get a lot of options for the NCERT Science Solution book of Class 9, but on the basis of reviews and student’s feedback, Goprep is considered as one of the best platforms to view NCERT solutions for CBSE Class 9 Science. The experts are experienced and know the important topics. The answers given are simple and you will not find yourself stuck at any step of the solution. Not to forget, the solutions are prepared keeping in mind the latest syllabus approved by CBSE. You can easily prepare for the Science exam if you are planning to score good marks.

  • Can I prepare for my exam with the help of NCERT Solutions?

    Yes, you can prepare for your exam by using NCERT solutions for 9th Class Science, as the solutions given are prepared on the basis of the official syllabus. You will find the solutions to all the chapters of the NCERT textbook. Also, it is always advisable to prepare from the NCERT textbook for the exam. Apart from solutions, you can also solve the previous year papers and practise similar questions from the other reference books.

  • Can I get answers of all the chapters in Goprep's NCERT Solutions for Class 9 Science?

    Yes, Goprep's NCERT Solutions for Class 9 Science covers all the chapters. Not even a single chapter is being missed by our experts. Also, the solutions are free from any error.

  • Are NCERT Solutions for Class 9 Science based on the latest syllabus?

    Yes, the solutions of Class 9th Science are prepared based on the latest official syllabus released by CBSE. You will not find any solution or the explanation from outside of the syllabus.