Science is a fascinating subject that explores the wonders of the natural world. For CBSE Class 9 students, mastering the fundamentals is essential for building a strong foundation for higher classes and competitive exams. At Dhingra Classes Nashik, we believe that consistent practice of Multiple Choice Questions (MCQs) , Short Answer Questions, Long Answer Questions, and Activities is the key to excelling in Science.

In this article, we provide a comprehensive set of 25 solved MCQs, 25 solved short Q&A, 15 solved long Q&A, and 4 solved activities based on Lesson 1: Matter in Our Surroundings from the NCERT Class 9 Science syllabus (2026-2027) . This guide is designed to help students revise effectively and build confidence for their school and board examinations.

CBSE Class 9 Science – Lesson 1: Matter in Our Surroundings

Key Concepts Covered:

• Physical nature of matter

• Characteristics of particles of matter

• States of matter (Solid, Liquid, Gas)

• Interconversion of states of matter

• Evaporation and its effects

• Factors affecting evaporation

• Sublimation, Condensation, Deposition

• Latent heat of fusion and vaporization

📌 Section A – 25 Solved MCQs (Multiple Choice Questions)

1. Which of the following is NOT a state of matter?
(a) Solid
(b) Liquid
(c) Gas
(d) Energy

✅ Answer: (d) Energy

2. The process by which a solid changes directly into a gas is called:
(a) Evaporation
(b) Sublimation
(c) Condensation
(d) Melting

✅ Answer: (b) Sublimation

3. Which of the following has the highest kinetic energy?
(a) Solid
(b) Liquid
(c) Gas
(d) All have equal kinetic energy

✅ Answer: (c) Gas

4. The interconversion of states of matter is caused by:
(a) Change in temperature
(b) Change in pressure
(c) Both (a) and (b)
(d) None of the above

✅ Answer: (c) Both (a) and (b)

5. The process by which a liquid changes into a gas at any temperature is called:
(a) Boiling
(b) Evaporation
(c) Sublimation
(d) Condensation

✅ Answer: (b) Evaporation

6. Which of the following particles is the smallest?
(a) Atom
(b) Molecule
(c) Ion
(d) Electron

✅ Answer: (a) Atom

7. The force of attraction between particles is maximum in:
(a) Solids
(b) Liquids
(c) Gases
(d) All are equal

✅ Answer: (a) Solids

8. The process by which a gas changes into a liquid is called:
(a) Evaporation
(b) Sublimation
(c) Condensation
(d) Melting

✅ Answer: (c) Condensation

9. Which of the following does not have a fixed shape or volume?
(a) Solid
(b) Liquid
(c) Gas
(d) Both (b) and (c)

✅ Answer: (c) Gas

10. The process of a liquid turning into a solid is called:
(a) Melting
(b) Freezing
(c) Condensation
(d) Sublimation

✅ Answer: (b) Freezing

11. Which of the following statements is true for particles of matter?
(a) Particles are continuously moving.
(b) Particles have spaces between them.
(c) Particles attract each other.
(d) All of the above

✅ Answer: (d) All of the above

12. The temperature at which a liquid changes into a gas at atmospheric pressure is called:
(a) Boiling point
(b) Melting point
(c) Freezing point
(d) Sublimation point

✅ Answer: (a) Boiling point

13. Which of the following is a pure substance?
(a) Water
(b) Milk
(c) Soil
(d) Air

✅ Answer: (a) Water

14. Which of the following is a characteristic of gases?
(a) Definite shape and volume
(b) Definite volume but no fixed shape
(c) No definite shape or volume
(d) Definite shape but no fixed volume

✅ Answer: (c) No definite shape or volume

15. The process by which a solid changes into a liquid is called:
(a) Freezing
(b) Melting
(c) Condensation
(d) Sublimation

✅ Answer: (b) Melting

16. The interconversion of states of matter is a:
(a) Physical change
(b) Chemical change
(c) Both (a) and (b)
(d) Neither (a) nor (b)

✅ Answer: (a) Physical change

17. Which of the following particles are present in matter?
(a) Atoms
(b) Molecules
(c) Ions
(d) All of the above

✅ Answer: (d) All of the above

18. The process by which a gas changes directly into a solid is called:
(a) Sublimation
(b) Deposition
(c) Condensation
(d) Evaporation

✅ Answer: (b) Deposition

19. Which of the following has the strongest intermolecular forces?
(a) Solid
(b) Liquid
(c) Gas
(d) All are equal

✅ Answer: (a) Solid

20. The kinetic energy of particles is directly proportional to:
(a) Temperature
(b) Pressure
(c) Volume
(d) Density

✅ Answer: (a) Temperature

21. Which of the following is NOT a characteristic of matter?
(a) Mass
(b) Volume
(c) Colour
(d) Energy

✅ Answer: (d) Energy

22. The process of evaporation increases with:
(a) Increase in temperature
(b) Increase in surface area
(c) Decrease in humidity
(d) All of the above

✅ Answer: (d) All of the above

23. The latent heat of fusion of ice is:
(a) 80 cal/g
(b) 540 cal/g
(c) 100 cal/g
(d) 50 cal/g

✅ Answer: (a) 80 cal/g

24. The latent heat of vaporization of water is:
(a) 80 cal/g
(b) 540 cal/g
(c) 100 cal/g
(d) 50 cal/g

✅ Answer: (b) 540 cal/g

25. Which of the following statements is true?
(a) Solids have a definite shape and volume.
(b) Liquids have a definite shape but no fixed volume.
(c) Gases have a definite volume but no fixed shape.
(d) All of the above

✅ Answer: (a) Solids have a definite shape and volume.

📌 Section B – 25 Solved Short Answer Questions (2–3 Marks)

Q1. What is matter? Give examples.

Answer: Matter is anything that has mass and occupies space. All living and non-living things around us are made up of matter.
Examples: Air, water, food, paper, etc.

Q2. What are the characteristics of particles of matter?

Answer: The characteristics of particles of matter are:

1. Particles are very small.

2. Particles are continuously moving.

3. Particles have spaces between them.

4. Particles attract each other.

Q3. What is the difference between a solid, liquid, and gas?

Q4. What is sublimation? Give two examples.

Answer: Sublimation is the process by which a solid changes directly into a gas without passing through the liquid state.
Examples:

• Dry ice (solid CO₂) → gas

• Camphor → gas

Q5. What is evaporation? What are the factors affecting evaporation?

Answer: Evaporation is the process by which a liquid changes into a gas at any temperature.
Factors affecting evaporation:

1. Temperature – Increases with increase in temperature.

2. Surface Area – Increases with increase in surface area.

3. Humidity – Decreases with increase in humidity.

4. Wind Speed – Increases with increase in wind speed.

Q6. What is the boiling point of water? What happens at the boiling point?

Answer: The boiling point of water is 100°C (at 1 atm pressure). At the boiling point, water changes from a liquid to a gas (vapor). The temperature remains constant during boiling because the heat supplied is used to overcome intermolecular forces.

Q7. What is latent heat?

Answer: Latent heat is the amount of heat energy required to change the state of a substance without changing its temperature.
Types:

• Latent heat of fusion (solid → liquid) – 80 cal/g for ice.

• Latent heat of vaporization (liquid → gas) – 540 cal/g for water.

Q8. Why does temperature remain constant during melting?

Answer: During melting, the heat supplied is used to overcome the intermolecular forces of attraction and convert the solid into a liquid. This heat does not increase the kinetic energy of particles, so the temperature remains constant.

Q9. What is the effect of pressure on the state of matter?

Answer: Increasing pressure can convert gases into liquids and liquids into solids. For example, carbon dioxide gas is compressed to form liquid CO₂, which is used in fire extinguishers.

Q10. Why do we feel cool when we apply perfume on our skin?

Answer: Perfume contains volatile substances that evaporate quickly. During evaporation, the particles absorb energy from the skin, causing the skin to cool down.

Q11. What is diffusion? Give an example.

Answer: Diffusion is the process by which particles of matter move from a region of higher concentration to a region of lower concentration.
Example: The smell of food spreads from the kitchen to other rooms.

Q12. Why are gases highly compressible?

Answer: Gases have large intermolecular spaces, and their particles are far apart. This allows them to be compressed easily by applying pressure.

Q13. What is the melting point of ice?

Answer: The melting point of ice is 0°C (at 1 atm pressure). At this temperature, ice changes from solid to liquid.

Q14. Why does the temperature of a substance remain constant during boiling?

Answer: During boiling, the heat supplied is used to overcome the intermolecular forces of attraction and convert the liquid into a gas. The temperature remains constant until the entire liquid has vaporized.

Q15. What is the difference between evaporation and boiling?

Q16. Why does a desert cooler cool better on a hot day?

Answer: On a hot day, the temperature is high, and the air is dry (low humidity). Both factors increase the rate of evaporation, which causes cooling.

Q17. What is condensation? Give an example.

Answer: Condensation is the process by which a gas changes into a liquid.
Example: Water vapor in the air condenses into water droplets on cold surfaces.

Q18. Why do we use dry ice to preserve food?

Answer: Dry ice (solid CO₂) sublimes into CO₂ gas, absorbing heat from its surroundings. This lowers the temperature and keeps food fresh.

Q19. What is the effect of temperature on the kinetic energy of particles?

Answer: As temperature increases, the kinetic energy of particles increases. This causes particles to move faster and increase the rate of processes like evaporation and diffusion.

Q20. Why do solids have a definite shape?

Answer: In solids, particles are closely packed with strong intermolecular forces, giving them a fixed shape and volume.

Q21. What is the difference between a pure substance and a mixture?

Answer:

• Pure Substance: Made up of only one type of particle.

• Mixture: Made up of two or more substances mixed together.

Q22. Why do liquids flow but solids do not?

Answer: In liquids, particles have moderate intermolecular forces and can move past each other, allowing liquids to flow. In solids, particles are fixed in position.

Q23. What is the role of surface area in evaporation?

Answer: Evaporation increases with an increase in surface area because more particles are exposed to the surface, allowing more particles to escape into the air.

Q24. Why does humidity decrease the rate of evaporation?

Answer: Humidity is the amount of water vapor already present in the air. When the air is already saturated, the rate of evaporation decreases.

Q25. What is the difference between condensation and deposition?

📌 Section C – 15 Solved Long Answer Questions (5 Marks)

Q1. Explain the interconversion of states of matter with a diagram.

Answer: The interconversion of states of matter involves changing one state to another by changing temperature or pressure.

Diagram:
Solid ↔ Liquid ↔ Gas
(Sublimation: Solid → Gas; Deposition: Gas → Solid)

Process:

• Melting: Solid → Liquid

• Freezing: Liquid → Solid

• Vaporization: Liquid → Gas

• Condensation: Gas → Liquid

• Sublimation: Solid → Gas

• Deposition: Gas → Solid

Q2. Explain the kinetic theory of matter.

Answer: The kinetic theory of matter explains the behavior of particles in different states:

1. Particles are continuously moving – They possess kinetic energy.

2. Kinetic energy increases with temperature – As temperature rises, particles move faster.

3. Particles have spaces between them – The spaces are maximum in gases and minimum in solids.

4. Particles attract each other – The force of attraction is strongest in solids and weakest in gases.

Q3. What is the difference between evaporation and boiling?

Q4. Why does a desert cooler cool better on a hot day?

Answer: A desert cooler cools better on a hot day because:

• The temperature is high, which increases the rate of evaporation.

• The air is dry (low humidity), which also increases the rate of evaporation.

• Evaporation causes cooling, making the air feel cooler.

Q5. Explain the concept of latent heat of fusion and latent heat of vaporization.

Answer:

• Latent Heat of Fusion: The amount of heat energy required to convert 1 gram of a solid into a liquid at its melting point without changing its temperature.
  Example: Ice melts at 0°C, and the latent heat of fusion of ice is 80 cal/g.

• Latent Heat of Vaporization: The amount of heat energy required to convert 1 gram of a liquid into a gas at its boiling point without changing its temperature.
  Example: Water boils at 100°C, and the latent heat of vaporization of water is 540 cal/g.

Q6. Why does the temperature of a substance remain constant during melting or boiling?

Answer: During melting or boiling, the heat supplied is used to overcome the intermolecular forces of attraction rather than increasing the kinetic energy of the particles. Therefore, the temperature remains constant until the entire substance has changed its state.

Q7. What is the effect of temperature and pressure on the state of matter?

Answer:

• Effect of Temperature: Increasing temperature increases the kinetic energy of particles, causing them to move faster and change state (e.g., solid → liquid → gas).

• Effect of Pressure: Increasing pressure brings particles closer together, causing gases to liquefy or liquids to solidify.

Q8. Why are gases compressible but solids are not?

Answer:

• Gases have large intermolecular spaces, allowing particles to move closer together when pressure is applied, making them compressible.

• Solids have very little intermolecular space, and their particles are closely packed, making them incompressible.

Q9. What is diffusion? Give an example.

Answer: Diffusion is the process by which particles of matter move from a region of higher concentration to a region of lower concentration.
Example: The smell of food spreads from the kitchen to other rooms due to the diffusion of the aroma particles in the air.

Q10. Why does a liquid evaporate faster in a larger container?

Answer: A liquid evaporates faster in a larger container because the surface area is larger, allowing more particles to escape into the air. Evaporation is a surface phenomenon, so increasing the surface area increases the rate of evaporation.

Q11. Explain the terms: melting point and boiling point with examples.

Answer:

• Melting Point: The temperature at which a solid changes into a liquid.
  Example: Ice melts at 0°C.

• Boiling Point: The temperature at which a liquid changes into a gas.
  Example: Water boils at 100°C.

Q12. Why do we use pressure cookers to cook food faster?

Answer: In a pressure cooker, the pressure is increased, which raises the boiling point of water. This allows food to cook faster at a higher temperature.

Q13. What is the difference between physical and chemical changes?

Q14. Why does the level of water in a glass decrease when kept for a long time?

Answer: The water level decreases because the particles of water evaporate into the air. Evaporation occurs at the surface of the liquid, and the water particles escape as vapor.

Q15. Explain why food tastes better when it is hot.

Answer: When food is hot, its particles have higher kinetic energy, which increases the diffusion of aroma particles into the air. This makes the food smell better and enhances the taste experience.

📌 Section D – 4 Solved Activities

Activity 1: Observation of Matter – Dissolving Sugar in Water

Procedure: Take a glass of water and add a spoonful of sugar. Stir it well and observe.

Observation: The sugar disappears, and the water becomes sweet. The sugar particles have dissolved in the water.

Conclusion: Sugar particles are very small and have spaces between them, allowing them to fill the gaps between water particles.

Activity 2: Diffusion of Potassium Permanganate

Procedure: Take a beaker filled with water and add a few crystals of potassium permanganate. Observe the color spreading slowly.

Observation: The purple color spreads throughout the water without any stirring.

Conclusion: The particles of potassium permanganate diffuse into the water due to the continuous movement of particles.

Activity 3: Sublimation of Camphor

Procedure: Take a few crystals of camphor in a watch glass and place it on a tripod stand. Heat it gently.

Observation: The camphor crystals disappear and a white vapor is observed.

Conclusion: Camphor undergoes sublimation—it changes directly from solid to gas without becoming liquid.

Activity 4: Observation of Evaporation

Procedure: Take a cotton ball soaked in water and place it on a plate. Keep it in the sun for a few hours.

Observation: The cotton ball becomes dry. The water has evaporated.

Conclusion: Evaporation is the process by which a liquid changes into a gas at any temperature. Sunlight increases the rate of evaporation.

How Dhingra Classes Helps Students Master Science

At Dhingra Classes Nashik, we provide:

• Conceptual learning – Building strong fundamentals in Physics, Chemistry, and Biology.

• Regular practice – Worksheets, MCQs, and mock tests.

• Doubt-clearing sessions – Instant clarification of queries.

• Personalized feedback – Identifying weak areas and providing targeted support.

Contact Dhingra Classes

• Phone: 98230 62106

• Email: dhingraclassesnsk@gmail.com

• Website: www.dhingraclassesnashik.com

• Address: Plot No 3, XQ3G+H3M Deacon Homes, 301C, opp. Metro Zone, near Guru Govind Sing, Samarth Nagar, Dnyaneshwar Nagar, Pathardi Phata, Nashik, Maharashtra 422009

Conclusion

Mastering Science Lesson 1: Matter in Our Surroundings requires a thorough understanding of concepts and consistent practice of MCQs, short Q&A, long Q&A, and activities. By solving these questions, students can build confidence and score high marks in their CBSE Class 9 examinations.

At Dhingra Classes Nashik, we are committed to helping students achieve academic excellence through expert guidance and structured practice. Join us and embark on your journey to success!