Important Questions for Class 9 Science with Answers

Important questions for Class 9 Science with answers are a curated set of practice questions drawn from the CBSE 2026 syllabus across Physics, Chemistry, and Biology. They cover all 12 chapters in the current syllabus and are organised by marks format  1-mark, 3-mark, 5-mark, assertion-reason, and case-based. Students use them to revise key concepts, improve answer writing, and prepare for different exam question types.

Class 9 Science carries 80 marks in theory and 20 marks in internal assessment. Getting the chapter-wise and marks-wise revision right is what separates a 60-mark paper from an 80-mark one. This page gives you CBSE important questions for Class 9 Science with answers, built around the 2026 exam pattern. Chapter-wise important questions, class 9 science 3-mark 5-mark questions, assertion-reason sets, and class 9 science extra questions with answers are all included. Use this page to revise faster, write better, and walk into your exam knowing exactly what to expect.

Key Takeaways

Marks Weightage for Class 9 Science

Unit III: Motion, Force and Work; carries the highest marks in theory. Chapters on Motion, Force and Laws of Motion, Gravitation, and Work and Energy together account for 27 marks. Prioritise these chapters alongside Unit I chemistry chapters during revision.

Class 9 Science Chapter Wise Important Questions

Class 9 Science chapter wise important questions help students revise one chapter at a time without losing track of marks weightage. This format works well for school tests, periodic tests, and final exam revision.

Class 9 Science Most Important Questions

These class 9 science most important questions focus on concepts that students see often in school exams. They cover high-priority topics from chemistry, physics, and biology.

Important Questions of Class 9 Science for Quick Revision

These important questions of class 9 science work best for last-minute revision. Use them to check concept clarity before moving to marks-wise written practice.

Q1. What does matter consist of?

Give examples of its three states. Matter is anything that has mass and occupies space. The three states of matter are solid, liquid, and gas. A chair is a solid, water is a liquid, and air is a gas.

Q2. What is the law of conservation of mass?

The law of conservation of mass states that mass can neither be created nor destroyed in a chemical reaction. The total mass of reactants equals the total mass of products.

Q3. What is the difference between a physical change and a chemical change?

A physical change alters the form or appearance of a substance without changing its chemical composition. Examples include melting ice and dissolving sugar. A chemical change alters the chemical composition and produces new substances. Examples include burning wood and rusting iron.

Q4. Define force. What are its two types?

Force is a push or pull on an object that changes or tends to change its state of motion or shape. The two main types are contact forces (friction, tension, normal force) and non-contact forces (gravitational force, magnetic force, electrostatic force).

Q5. What is Newton's second law of motion?

Newton's second law states that the rate of change of momentum of an object is directly proportional to the net external force applied. In equation form: F = ma, where F is force, m is mass, and a is acceleration.

Q6. What is the universal law of gravitation?

Every object in the universe attracts every other object with a force directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres.

Q7. What is the cell?

Distinguish between prokaryotic and eukaryotic cells. The cell is the basic structural and functional unit of life. Prokaryotic cells have no membrane-bound nucleus (example: bacteria). Eukaryotic cells have a well-defined nucleus enclosed in a membrane (example: plant and animal cells).

Q8. Describe the structure of an atom?
An atom consists of a nucleus at its centre, containing protons and neutrons. Electrons orbit the nucleus in fixed energy levels called shells. The number of protons determines the atomic number and identity of the element.

Q9. What are natural resources?

Classify them. Natural resources are materials found in nature that living organisms use. They are classified into renewable resources (sunlight, water, wind) and non-renewable resources (coal, petroleum, natural gas).

Q10. What is photosynthesis?
Write its equation. Photosynthesis is the process by which green plants use sunlight, water, and carbon dioxide to produce glucose and oxygen. Carbon dioxide + Water + Sunlight → Glucose + Oxygen

Class 9 Science 1-Mark Important Questions

1-mark questions test direct recall. Expect MCQs and very short answers in this format.

Q1. What is the SI unit of force?

Newton (N).

Q2. Name the scientist who proposed the cell theory?

Matthias Schleiden and Theodor Schwann proposed the cell theory. Rudolf Virchow later added that new cells arise from pre-existing cells.

Q3. What is the atomic number of an element?

The atomic number of an element is the number of protons in the nucleus of its atom.

Q4. Name the hormone secreted by the adrenal gland in emergency situations?

Adrenaline.

Q5. What is the SI unit of work?

Joule (J).

Q6. Which plant tissue is responsible for growth?

Meristematic tissue.

Q7. State Newton's first law of motion?

An object remains at rest or in uniform motion in a straight line unless an external force acts on it.

Q8. What is latent heat?

Latent heat is the heat energy absorbed or released by a substance during a change of state, without a change in temperature.

Class 9 Science 3-Mark 5-Mark Questions

Class 9 science 3-mark 5-mark questions require structured written answers. A 3-mark answer needs a definition, an explanation, and one or two examples. A 5-mark answer needs a full explanation, comparison, or diagram-based response.

3-Mark Questions

Q1. Explain the difference between evaporation and boiling?

Evaporation occurs only at the surface of a liquid at any temperature. Boiling occurs throughout the liquid and only at the boiling point. Evaporation is a slow process; boiling is rapid. Evaporation causes cooling because it absorbs latent heat from surroundings. Boiling requires an external heat source.

Q2. State and explain Newton's third law of motion with an example?

Newton's third law states that for every action, there is an equal and opposite reaction. The two forces act on different objects. Example: when a gun is fired, the bullet moves forward (action) and the gun recoils backward (reaction) with equal force.

Q3. What are the differences between plant cells and animal cells?

Q4. Explain the law of conservation of energy with one example?

The law of conservation of energy states that energy can neither be created nor destroyed; it can only be converted from one form to another. A ball dropped from a height has maximum potential energy at the top and maximum kinetic energy just before it hits the ground. The total mechanical energy remains constant (ignoring air resistance).

Q5. What is Archimedes' principle?

State one application. Archimedes' principle states that when a body is immersed fully or partially in a fluid, it experiences an upward buoyant force equal to the weight of the fluid displaced. Application: ships are designed to displace enough water so the buoyant force equals their weight, allowing them to float.

5-Mark Questions

Q1. Describe the structure and function of a neuron?
A neuron is the structural and functional unit of the nervous system. It has three parts:

• Cell body (cyton): contains the nucleus and controls the neuron's activities
• Dendrites: short, branched extensions that receive nerve impulses from other neurons
• Axon: a long fibre that carries impulses away from the cell body to the next neuron or to a muscle or gland

Neurons carry electrical signals from one part of the body to another. When a stimulus is detected, the impulse travels from the dendrite through the cell body along the axon to the next cell via the synapse.

Q2. Explain the different types of motion with examples?

• Uniform motion: object covers equal distances in equal time intervals. Example: a car moving at constant speed on a straight road.
• Non-uniform motion: object covers unequal distances in equal time intervals. Example: a car accelerating from a traffic signal.
• Circular motion: object moves along a circular path. Example: a stone tied to a string and whirled.
• Oscillatory motion: object moves to and fro about a fixed point. Example: a pendulum.
• Random motion: no fixed path or direction. Example: movement of gas molecules.

Q3. Compare the nervous and hormonal systems of coordination in animals?

Class 9 Science Assertion Reason Questions

Class 9 science assertion reason questions test concept clarity more than memory. Two statements are given. You identify whether both are true and whether the reason correctly explains the assertion.

Sample Assertion-Reason Question:

Assertion (A): An object moving with uniform velocity has zero acceleration. Reason (R): Acceleration is the rate of change of velocity. If velocity is constant, the change in velocity is zero.

Options: a) Both A and R are true, and R is the correct explanation of A. b) Both A and R are true, but R is not the correct explanation of A. c) A is true but R is false. d) A is false but R is true.

Ans: a) Both A and R are true, and R is the correct explanation of A.

Sample Case-Based Question:

Riya noticed that when she mixed hot water and cold water, the final temperature was between the two. Her teacher explained that heat flows from a body at higher temperature to a body at lower temperature until thermal equilibrium is reached.

Q1. What is thermal equilibrium?

Thermal equilibrium is the state where two bodies in contact reach the same temperature and there is no net flow of heat between them.

Q2. Which law does this observation support?

This supports the law of conservation of energy: the heat lost by hot water equals the heat gained by cold water.

Class 9 Science Exam Important Questions

Class 9 science exam important questions help students focus on formats that appear most often in school papers. These include 1-mark, 3-mark, 5-mark, assertion-reason, and case-based questions. All formats are covered with sample answers on this page.

Class 9 Science Important Questions PDF

Many students search for class 9 science important questions PDF when they want chapter-wise practice in one place. A PDF download is not available on this page, but the complete question bank is available chapter by chapter using the links in the chapter table above. Use those pages to print or save questions for offline revision.

Class 9 Science Extra Questions with Answers

Students preparing beyond the NCERT textbook exercises need class 9 science extra questions with answers to strengthen weaker chapters. The questions in the 3-mark, 5-mark, and assertion-reason sections above go beyond standard NCERT questions. For deeper chapter-wise extra practice, use the chapter links in the table above.

How to Use Class 9 Science Important Questions for Revision

Start with the chapter table above and identify which units carry the most marks.

Revise Unit III (Motion, Force and Work) first. It has the highest theory weightage at 27 marks.

Use 1-mark questions for rapid recall practice in the last two weeks before exams.

Use 3-mark and 5-mark questions to practise structured written answers. Time yourself — 3-mark answers should take 4-5 minutes and 5-mark answers should take 8-10 minutes.

Use assertion-reason questions to strengthen conceptual clarity, not just memory.

Return to chapters where you score below 50% in self-assessment and redo those chapter-wise important questions.

For cross-subject practice, Class 9 Maths Number Systems Important Questions can help you stay sharp on quantitative reasoning alongside science revision.

Additional Study Materials for Class 9 Science

Extramarks complements classroom learning. Use these materials alongside your teacher's guidance for the best results.