CBSE Class 9 Science Sample Paper 2026 (with Solutions) — Free PDF
This is a full-length CBSE Class 9 Science paper built to the board's own pattern: 39 questions across five sections for 80 marks in 3 hours, covering matt
TL;DR: This is a full-length CBSE Class 9 Science paper built to the board's own pattern: 39 questions across five sections for 80 marks in 3 hours, covering…
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This is a full-length CBSE Class 9 Science paper built to the board's own pattern: 39 questions across five sections for 80 marks in 3 hours, covering matter, atoms and molecules, cell biology and tissues, motion, force, gravitation, work and energy, and sound in the proportions the board uses. Section A is objective and Section E is case-based. Every question carries a full worked solution setting out the reasoning, not just the final answer.
Board: CBSE · Class: Class 9 · Subject: Science · Total: 80 marks · Time: 3 hours
Section A — Objective (1 mark each) — 20 marks
Questions 1–18 are multiple choice. Questions 19 and 20 are Assertion–Reason: mark (a) if both A and R are true and R explains A, (b) if both are true but R does not explain A, (c) if A is true and R is false, (d) if A is false and R is true.
Q1. The process by which a solid changes directly into a gas is called (1 mark)
Answer: Sublimation. Camphor, naphthalene and ammonium chloride all sublime on heating.
Q2. Evaporation causes cooling because (1 mark)
Answer: The escaping particles take latent heat from the liquid and its surroundings, lowering their temperature.
Q3. A solution of common salt in water is an example of (1 mark)
Answer: A homogeneous mixture — the composition is uniform throughout and the particles cannot be seen or separated by filtration.
Q4. Which of these is a compound: air, brass, or water? (1 mark)
Answer: Water. Air and brass are mixtures, whereas water has hydrogen and oxygen chemically combined in a fixed 2 : 1 ratio by atoms.
Q5. The technique used to separate a mixture of two miscible liquids with boiling points differing by less than 25 K is (1 mark)
Answer: Fractional distillation, using a fractionating column that provides repeated condensation and vaporisation.
Q6. The atomicity of a phosphorus molecule, P₄, is (1 mark)
Answer: Four — the molecule contains four atoms of phosphorus.
Q7. The number of moles in 22 g of carbon dioxide (molar mass 44 g/mol) is (1 mark)
Answer: 0.5 mol. Moles = mass/molar mass = 22/44 = 0.5.
Q8. Isotopes of an element have (1 mark)
Answer: The same atomic number but different mass numbers — the same number of protons and a different number of neutrons.
Q9. The particle discovered by James Chadwick was the (1 mark)
Answer: Neutron, an electrically neutral particle of mass roughly equal to that of a proton.
Q10. The plastid that gives a green colour to plant cells is the (1 mark)
Answer: Chloroplast, which contains the pigment chlorophyll and is the site of photosynthesis.
Q11. The tissue that transports food in plants is (1 mark)
Answer: Phloem. Xylem carries water and minerals; phloem carries the products of photosynthesis in both directions.
Q12. Which animal tissue connects muscle to bone? (1 mark)
Answer: Tendon — a strong, inelastic connective tissue. Ligaments, by contrast, connect bone to bone and are elastic.
Q13. The SI unit of force is the (1 mark)
Answer: Newton, defined as the force that gives a mass of one kilogram an acceleration of one metre per second squared.
Q14. A body moving with uniform velocity has (1 mark)
Answer: Zero acceleration, since acceleration is the rate of change of velocity and the velocity is not changing.
Q15. The momentum of a 5 kg body moving at 4 m/s is (1 mark)
Answer: 20 kg m/s. Momentum p = mv = 5 × 4 = 20 kg m/s, directed along the motion.
Q16. The work done when a force of 10 N moves a body 5 m in the direction of the force is (1 mark)
Answer: 50 J. Work W = F × s = 10 × 5 = 50 joules.
Q17. The frequency of a sound wave of wavelength 2 m travelling at 340 m/s is (1 mark)
Answer: 170 Hz. From v = fλ, f = 340/2 = 170 Hz.
Q18. The acceleration due to gravity on the surface of the Moon is about (1 mark)
Answer: One sixth of that on Earth, roughly 1.63 m/s², because the Moon has both a much smaller mass and a smaller radius.
Q19. Assertion (A): A sponge is a solid though it can be compressed. Reason (R): A sponge has minute holes filled with air that escape when it is pressed. (1 mark)
Answer: (a) Both true and R explains A. The sponge keeps a definite shape and volume of its own material; what compresses is the trapped air, exactly as the reason says.
Q20. Assertion (A): The mass of a body remains constant everywhere. Reason (R): Weight depends on the acceleration due to gravity at the place. (1 mark)
Answer: (b) Both are true but R does not explain A. Mass is constant because it measures the quantity of matter; the behaviour of weight is a separate fact and does not account for that constancy.
Section B — Very Short Answer (2 marks each) — 12 marks
Answer all 6 questions. Each carries 2 marks.
Q1. Why do gases exert more pressure than solids and liquids on the walls of a container? (2 marks)
Answer: In a gas the particles are very far apart and move at high speed in all directions, so they collide frequently with the walls of the container. Each collision exerts a force, and the large number of collisions per second over the whole surface gives rise to the pressure.
Q2. State the law of conservation of mass and give one example. (2 marks)
Answer: In a chemical reaction, mass can neither be created nor destroyed, so the total mass of the products equals the total mass of the reactants. For example, when 12 g of carbon burns completely in 32 g of oxygen, exactly 44 g of carbon dioxide is formed.
Q3. Write two differences between a plant cell and an animal cell. (2 marks)
Answer: A plant cell has a rigid cell wall of cellulose outside the plasma membrane, while an animal cell has only the plasma membrane. A plant cell contains plastids, including chloroplasts, and usually one large central vacuole, whereas an animal cell has no plastids and only small vacuoles if any.
Q4. State Newton's third law of motion and give one everyday example. (2 marks)
Answer: To every action there is an equal and opposite reaction, and the two act on different bodies. When a swimmer pushes the water backwards with her hands, the water pushes her forwards with an equal force, which is what moves her through the pool.
Q5. Define echo and state the minimum distance needed to hear one clearly. (2 marks)
Answer: An echo is the repetition of a sound caused by its reflection from a distant obstacle. The sensation of sound persists in the brain for about 0.1 s, so the reflected sound must return after at least that interval; at 344 m/s the sound must cover 34.4 m in going and returning, so the obstacle must be at least 17.2 m away.
Q6. Why is the weight of an object on the Moon less than on the Earth? (2 marks)
Answer: Weight is the gravitational force on the object, W = mg, and the value of g depends on the mass and radius of the body producing the field. The Moon's mass is much smaller than the Earth's, so its g is about one sixth of the Earth's and the same object weighs about one sixth as much, even though its mass is unchanged.
Section C — Short Answer (3 marks each) — 21 marks
Answer all 7 questions. Each carries 3 marks.
Q1. Explain why the temperature of a substance does not rise while it is melting, even though heat is being supplied. (3 marks)
Answer: During melting the heat supplied does not increase the kinetic energy of the particles, so the thermometer reading does not change. Instead it is used to overcome the forces of attraction holding the particles in their fixed positions in the solid lattice. This hidden heat is the latent heat of fusion, and only when the whole solid has become liquid does further heating begin to raise the temperature again.
Q2. Distinguish between a mixture and a compound, giving two points of difference and one example of each. (3 marks)
Answer: The components of a mixture are present in any proportion and keep their own properties, whereas a compound has its elements combined in a fixed proportion by mass and shows entirely new properties. A mixture can be separated by physical means such as filtration or distillation, while a compound can be broken up only by a chemical reaction. Air is a mixture of gases; water is a compound of hydrogen and oxygen.
Q3. Calculate the number of molecules in 9 g of water. (Molar mass of water = 18 g/mol, Avogadro number = 6.022 × 10²³) (3 marks)
Answer: Number of moles = mass/molar mass = 9/18 = 0.5 mol. The number of molecules = number of moles × Avogadro number = 0.5 × 6.022 × 10²³ = 3.011 × 10²³ molecules.
Q4. Describe the structure and function of the mitochondrion. (3 marks)
Answer: The mitochondrion is a double-membraned organelle; its outer membrane is smooth and porous, while the inner membrane is deeply folded into cristae that greatly increase the surface area available for reactions. The space inside holds the matrix, which contains enzymes along with the organelle's own DNA and ribosomes, so it can make some of its own proteins. Its function is aerobic respiration: it completes the oxidation of glucose and releases energy as ATP, which is why it is called the powerhouse of the cell.
Q5. A car accelerates uniformly from 18 km/h to 36 km/h in 5 s. Calculate the acceleration and the distance covered. (3 marks)
Answer: Convert to SI: 18 km/h = 18 × 5/18 = 5 m/s and 36 km/h = 10 m/s. Acceleration a = (v − u)/t = (10 − 5)/5 = 1 m/s². Distance s = ut + ½at² = 5(5) + ½(1)(25) = 25 + 12.5 = 37.5 m.
Q6. State the law of conservation of energy and verify it for a body falling freely from a height h. (3 marks)
Answer: Energy can neither be created nor destroyed, only changed from one form to another, so the total energy of an isolated system stays constant. For a body of mass m released from height h: at the top its velocity is zero, so the energy is entirely potential, mgh. At a height x above the ground it has fallen (h − x) and gained a speed given by v² = 2g(h − x), so the kinetic energy is ½mv² = mg(h − x) and the potential energy is mgx; the total is mgh again. Just before striking the ground the potential energy is zero and v² = 2gh, so the kinetic energy is ½m(2gh) = mgh. The total is mgh at every stage.
Q7. Explain how sound is produced and why sound cannot travel through vacuum. (3 marks)
Answer: Sound is produced by a vibrating body. As the surface moves forward it pushes the particles of the surrounding medium together, creating a compression, and as it moves back it leaves them further apart, creating a rarefaction. These compressions and rarefactions travel outward as a longitudinal wave, and the particles themselves only oscillate about their mean positions rather than travelling with the wave. Since the wave needs particles to pass the disturbance from one to the next, and a vacuum contains no particles, sound cannot travel through it — which is why an electric bell in an evacuated jar becomes inaudible.
Section D — Long Answer (5 marks each) — 15 marks
Answer all 3 questions. Each carries 5 marks.
Q1. (a) State the postulates of Bohr's model of the atom. (b) Write the electronic configuration of an element with atomic number 18. (c) Define valency and give the valency of that element. (5 marks)
Answer: (a) Bohr proposed that electrons revolve round the nucleus only in certain permitted circular orbits called energy levels or shells; that while an electron stays in such an orbit it does not radiate energy, so the atom is stable; and that energy is absorbed or emitted only when an electron jumps from one orbit to another, the difference in energy appearing as radiation. (b) An element with atomic number 18 has 18 electrons, filled as K = 2, L = 8, M = 8, written 2, 8, 8 — this is argon. (c) Valency is the combining capacity of an atom, given by the number of electrons it must gain, lose or share to attain a completely filled outermost shell. Argon already has eight electrons in its outermost shell, so it neither gains nor loses electrons and its valency is zero, which is why it is chemically inert.
Q2. (a) Describe the three types of muscle tissue in animals, giving one location and one distinguishing feature of each. (b) Why is areolar tissue called packing tissue? (5 marks)
Answer: (a) Striated or skeletal muscle is made of long, cylindrical, unbranched multinucleate fibres with alternating light and dark bands; it is attached to bones, as in the limbs, and is under voluntary control, contracting rapidly and tiring quickly. Smooth or unstriated muscle has spindle-shaped, uninucleate cells without bands; it occurs in the walls of the alimentary canal, blood vessels and iris, and works involuntarily and slowly without tiring. Cardiac muscle has branched, uninucleate striated fibres joined by intercalated discs; it is found only in the heart and contracts rhythmically and involuntarily throughout life without fatigue. (b) Areolar tissue fills the space inside organs, fastens skin to the muscle beneath, and lies between and around the tissues it surrounds, holding them in place while allowing movement. Because its main role is to occupy the gaps and support neighbouring structures rather than to perform a specialised function of its own, it is described as packing tissue; it also aids repair after injury.
Q3. (a) State the universal law of gravitation and write its mathematical form. (b) Explain why a sheet of paper falls more slowly than a stone though gravity acts equally on both. (c) A body of mass 10 kg is at a height of 5 m. Calculate its potential energy. (Take g = 10 m/s²) (5 marks)
Answer: (a) Every body in the universe attracts every other body with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres: F = G m₁m₂/r², where G is the universal gravitational constant, 6.67 × 10⁻¹¹ N m² kg⁻². (b) In free fall all bodies would have the same acceleration g, independent of mass. What differs is air resistance: the sheet of paper has a very large surface area for its small weight, so the upward drag on it is comparable to its weight and it slows greatly, whereas the stone's weight is far larger than the drag on its small area. In an evacuated tube the two fall side by side, which shows that gravity indeed acts alike on both. (c) Potential energy = mgh = 10 × 10 × 5 = 500 J.
Section E — Case-based questions (4 marks each) — 12 marks
Answer all 3 case-based questions. Each has sub-parts totalling 4 marks.
Q1. CASE STUDY 1 — A student places some ice in a beaker and heats it steadily, recording the temperature every minute. The temperature rises from −10 °C to 0 °C, then stays at 0 °C for several minutes, then rises again to 100 °C, where it stays constant while the water boils. (i) Why does the temperature stay constant at 0 °C? (ii) Name the heat involved. (iii) Why does it stay constant again at 100 °C? (iv) Which requires more heat per kilogram? (4 marks)
Answer: (i) At 0 °C the ice is melting, and the heat supplied is being used to break the forces holding the particles in the solid lattice rather than to raise their kinetic energy, so the temperature does not change until all the ice has melted. (ii) This is the latent heat of fusion of ice, about 3.34 × 10⁵ J/kg. (iii) At 100 °C the water is boiling, and the heat is being used to separate the particles completely against the attractive forces to form vapour — the latent heat of vaporisation. (iv) Vaporisation requires far more heat per kilogram, about 22.6 × 10⁵ J/kg against 3.34 × 10⁵ J/kg, because the particles must be separated completely rather than merely freed to slide past one another.
Q2. CASE STUDY 2 — A bus starting from rest moves with a uniform acceleration of 0.1 m/s² for 2 minutes. (i) Convert the time to seconds. (ii) Find the speed acquired. (iii) Find the distance travelled. (iv) If the brakes then bring it to rest in 20 s, find the retardation. (4 marks)
Answer: (i) 2 minutes = 120 s. (ii) v = u + at = 0 + 0.1 × 120 = 12 m/s. (iii) s = ut + ½at² = 0 + ½(0.1)(120)² = ½(0.1)(14400) = 720 m. (iv) Now u = 12 m/s, v = 0 and t = 20 s, so a = (0 − 12)/20 = −0.6 m/s². The negative sign shows retardation of 0.6 m/s².
Q3. CASE STUDY 3 — A ship sends a sound pulse towards the sea bed and receives the echo after 3 s. The speed of sound in seawater is 1500 m/s. (i) Name this technique. (ii) Why is the time halved in the calculation? (iii) Calculate the depth. (iv) Give one other use of this technique. (4 marks)
Answer: (i) Echo ranging, or SONAR — sound navigation and ranging. (ii) The 3 s is the time for the pulse to travel down to the sea bed AND back to the ship, so the one-way time is half of it, 1.5 s. (iii) Depth = speed × one-way time = 1500 × 1.5 = 2250 m. (iv) The same principle is used to locate shoals of fish, submarines, icebergs and sunken wrecks, and in medicine an ultrasound scanner images internal organs by the same echo method.
FAQs
What is the marks distribution in Class 9 Science?
Physics (30), Chemistry (30), Biology (20) marks; 20 marks for practical assessment.
Which topics are most important for the board exam?
Force, motion, atoms, cells, photosynthesis, and respiration are high-weightage topics.
Are practicals compulsory in Class 9 Science?
Yes, students must conduct prescribed practicals and maintain a proper lab notebook.
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