The Particulate Nature of Matter is one of the most important chapters in Class 8 Science because it explains how everything around us is made of tiny particles. Although these particles cannot be seen with the naked eye, their behaviour helps us understand many everyday phenomena, such as diffusion, changes in the state of matter, and the movement of gases and liquids. Building a clear understanding of these concepts lays a strong foundation for higher classes and future chemistry topics.
This page brings together Class 8 Chapter 7 Particulate Nature of Matter MCQs with Answers in one place to support focused revision and exam preparation. Prepared according to the latest CBSE Board and NCERT syllabus, these Class 8 Science MCQs cover the chapter's most important concepts, including the properties of particles, intermolecular space, intermolecular force of attraction, Brownian motion, diffusion, and states of matter. Each question is accompanied by the correct answer and a concise explanation, making it easier to understand the concept and identify areas that need more practice.
Whether you are revising before a school test or strengthening your preparation for the final examination, these MCQs and Class 8 MCQs provide a practical way to evaluate your understanding and improve your confidence with the chapter.
Class 8 Chapter 7 Particulate Nature of Matter MCQs with Answers and Explanation
The following Class 8 Science Chapter 7 Particulate Nature of Matter MCQs with Answers are arranged to help you revise the chapter step by step. The questions cover both fundamental concepts and application-based situations that are commonly asked in CBSE school examinations.
Q. A student dissolves a spoon of sugar in a glass of water without stirring it. After some time, the water tastes sweet throughout the glass. Which property of particles of matter is mainly responsible for this observation?
A. Particles of matter have fixed positions.
B. Particles of matter are continuously moving.
C. Particles of matter always increase in size.
D. Particles of matter lose their mass in water.
Answer: B
Explanation:
Sugar particles move continuously and mix with the water particles on their own. This process is called diffusion. It shows that particles of matter are never at rest, even when the liquid appears still. Their constant movement allows substances to spread evenly without continuous stirring.
Q. Which statement best explains why gases are much easier to compress than solids?
A. Gas particles have very weak intermolecular forces and large spaces between them.
B. Gas particles are heavier than solid particles.
C. Solid particles move faster than gas particles.
D. Gases contain fewer particles than solids.
Answer: A
Explanation:
Compression depends mainly on the space available between particles. Gas particles are far apart and experience weak intermolecular attraction, leaving plenty of empty space that can be reduced. In solids, particles are packed closely together, making compression extremely difficult.
Q. A bottle of perfume is opened in one corner of a classroom. Students sitting far away can smell it after a few moments. This observation directly proves that:
A. Air has no mass.
B. Particles of gases move randomly and continuously.
C. Perfume particles become lighter than air.
D. Air changes into perfume.
Answer: B
Explanation:
Perfume spreads because its particles mix naturally with the particles of air. This happens through diffusion, which is possible because gas particles move freely in all directions. The activity demonstrates the continuous motion of particles rather than a change in the nature of air.
Q. Which of the following changes would most likely increase the rate of diffusion?
A. Cooling the substance before mixing.
B. Heating the substance so that particle movement increases.
C. Compressing the particles into a smaller space.
D. Keeping the substance completely still.
Answer: B
Explanation:
Heating gives particles more kinetic energy, allowing them to move faster. Faster-moving particles spread more quickly through another substance, increasing the rate of diffusion. This is why the smell of hot food spreads faster than the smell of cold food.
Q. A solid object keeps its shape even when it is moved from one place to another. Which property of its particles mainly explains this behaviour?
A. Large intermolecular spaces.
B. Strong intermolecular force of attraction.
C. Constant diffusion between particles.
D. Weak attraction among particles.
Answer: B
Explanation:
The particles in a solid are held together by strong intermolecular forces. They can only vibrate about fixed positions instead of moving freely. This strong attraction gives solids a definite shape and prevents them from flowing like liquids.
Q. Which statement correctly compares liquids and gases?
A. Both have fixed shape and fixed volume.
B. Liquids have weaker intermolecular attraction than gases.
C. Gases have larger intermolecular spaces than liquids.
D. Liquids cannot flow, but gases can.
Answer: C
Explanation:
Gas particles are much farther apart than liquid particles, giving gases larger intermolecular spaces. Because of this, gases spread easily, fill any container completely, and can be compressed more than liquids. Liquids, although they flow, still have a fixed volume.
Q. A student observes tiny pollen grains moving continuously in water under a microscope. This movement is known as:
A. Sublimation.
B. Brownian motion.
C. Condensation.
D. Compression.
Answer: B
Explanation:
Brownian motion is the random movement of tiny suspended particles caused by collisions with the surrounding water molecules. This observation provides strong evidence that particles of matter are constantly moving, even though they cannot be seen directly.
Q. Which situation best shows that particles of matter attract one another?
A. Water flows through a pipe.
B. A wooden block retains its shape after being placed on a table.
C. Air fills an empty balloon.
D. Steam spreads through a room.
Answer: B
Explanation:
A wooden block maintains its shape because its particles are held together by strong intermolecular forces. If there were no attractive forces between particles, solids would not remain rigid and would lose their definite shape easily.
Q. Why does ink spread more slowly in cold water than in warm water?
A. Cold water has no intermolecular spaces.
B. Particle movement is slower at lower temperatures.
C. Ink particles become heavier in cold water.
D. Warm water contains more air particles.
Answer: B
Explanation:
Temperature affects the kinetic energy of particles. In warm water, particles move faster and mix more quickly with ink. In cold water, particle movement slows down, reducing the speed of diffusion. This simple experiment demonstrates the relationship between heat and particle motion.
Q. Which statement about particles of matter is scientifically correct?
A. Particles remain completely still inside solids.
B. Particles always move with the same speed in every state of matter.
C. Particles possess kinetic energy and remain in continuous motion.
D. Particles disappear when matter changes its state.
Answer: C
Explanation:
All particles of matter have kinetic energy, which keeps them in continuous motion. Their speed depends on the state of matter and temperature. During a change of state, the particles do not disappear; only their arrangement and movement change.
Q. A student adds a few drops of blue ink to a beaker of still water. After some time, the entire water becomes light blue without stirring. Which conclusion is most appropriate?
A. Water changes its colour naturally after some time.
B. Ink particles move randomly and mix with water particles through diffusion.
C. Ink particles become lighter than water and settle at the bottom.
D. Water particles stop moving after the ink is added.
Answer: B
Explanation:
The spreading of ink in still water is a classic example of diffusion. Both ink and water particles are continuously moving, allowing them to mix naturally. This experiment shows that particles of matter are always in motion, even when no external force is applied.
Q. Which property of matter explains why a sponge can be compressed easily, even though it is a solid?
A. The particles of the sponge have no force of attraction.
B. Air trapped inside the tiny pores is pushed out when compressed.
C. Sponge particles change into a liquid when pressed.
D. Solids always have large intermolecular spaces.
Answer: B
Explanation:
A sponge is a solid, but it contains many tiny pores filled with air. When you press the sponge, the trapped air escapes, making it appear highly compressible. The particles of the sponge itself remain closely packed, just like in other solids.
Q. Which observation best supports the idea that particles of matter have spaces between them?
A. A balloon becomes lighter after inflation.
B. Sugar dissolves completely in water without increasing the water level significantly.
C. A metal spoon floats on water.
D. Ice changes directly into steam.
Answer: B
Explanation:
When sugar dissolves, its particles occupy the spaces between water particles instead of creating a noticeable increase in volume. This simple observation provides evidence that particles of matter are separated by tiny intermolecular spaces.
Q. Why do gases spread much faster than liquids?
A. Gas particles have greater kinetic energy and larger intermolecular spaces.
B. Liquids do not contain particles.
C. Gas particles are always heavier than liquid particles.
D. Liquids cannot change their position.
Answer: A
Explanation:
Gas particles move much more freely because they have weak intermolecular forces and large spaces between them. Their higher kinetic energy allows them to spread rapidly in all directions, making diffusion fastest in gases.
Q. A piece of camphor gradually becomes smaller when left in an open room. Which process is mainly responsible?
A. Condensation
B. Sublimation
C. Freezing
D. Diffusion
Answer: B
Explanation:
Camphor changes directly from a solid into vapour without passing through the liquid state. This process is known as sublimation. The vapour particles then spread into the surrounding air through diffusion, making the camphor slowly disappear.
Q. Which statement correctly explains why solids are difficult to compress?
A. Their particles have almost no space between them.
B. Their particles move faster than gas particles.
C. Solids contain fewer particles than liquids.
D. Their particles lose mass under pressure.
Answer: A
Explanation:
Solid particles are packed very closely together, leaving very little empty space. Because there is almost no room to push the particles closer, solids cannot be compressed easily. Strong intermolecular attraction further helps solids maintain their shape.
Q. A student compares the movement of particles in ice, water, and steam. In which substance do the particles have the highest kinetic energy?
A. Ice
B. Water
C. Steam
D. All have the same kinetic energy.
Answer: C
Explanation:
The kinetic energy of particles increases as matter changes from solid to liquid to gas. Steam is a gaseous state, so its particles move much faster than those in water or ice. Faster particle movement means greater kinetic energy.
Q. Which of the following changes occurs because particles lose heat and move closer together?
A. Evaporation
B. Melting
C. Condensation
D. Sublimation
Answer: C
Explanation:
During condensation, gas particles lose heat energy and slow down. As they move closer together, the gas changes into a liquid. This change demonstrates how temperature influences particle movement and the state of matter.
Q. Which statement best describes Brownian motion?
A. The movement of gas particles from high concentration to low concentration.
B. The random movement of tiny suspended particles due to collisions with surrounding particles.
C. The vibration of particles inside a solid only.
D. The expansion of solids when heated.
Answer: B
Explanation:
Brownian motion refers to the irregular zigzag movement of very small particles suspended in a liquid or gas. This movement occurs because surrounding particles constantly collide with them. It provides strong evidence that particles of matter are always moving.
Q. A closed bottle contains air. Which statement about the air particles inside the bottle is correct?
A. The particles remain fixed at one position.
B. The particles stop moving because the bottle is closed.
C. The particles continue moving randomly in all directions.
D. The particles settle at the bottom of the bottle over time.
Answer: C
Explanation:
Closing the bottle prevents the air from escaping, but it does not stop the particles from moving. Air particles continue their random motion and frequently collide with one another and with the walls of the bottle. This continuous movement is a basic property of gases.
Q. A metal lid becomes easier to open after warm water is poured over it. Which concept best explains this observation?
A. Metal particles lose mass when heated.
B. Heating increases the distance between metal particles due to expansion.
C. Water removes the force of attraction between particles permanently.
D. The lid changes into a different material.
Answer: B
Explanation:
When the metal lid is heated, its particles gain kinetic energy and vibrate more vigorously. This slightly increases the space between the particles, causing the lid to expand. Even a small expansion can make it easier to remove a tightly fitted lid from the container.
Q. Which observation provides the strongest evidence that particles of matter are always moving?
A. A wooden table remains in one place.
B. The fragrance of room freshener gradually spreads throughout the room.
C. A stone sinks in water.
D. Ice floats on water.
Answer: B
Explanation:
The fragrance spreads because perfume particles move continuously and mix with the particles of air. This process happens without stirring or external movement, showing that particles possess kinetic energy and remain in constant motion, even when they cannot be seen.
Q. Why does a gas completely fill the container in which it is kept?
A. Gas particles have no mass.
B. Gas particles move freely in all directions because of weak intermolecular forces.
C. The container pulls the gas particles equally from every side.
D. Gas particles remain fixed after entering the container.
Answer: B
Explanation:
Gas particles are separated by large intermolecular spaces and experience very weak forces of attraction. This allows them to move randomly in every direction until they occupy all the available space inside the container.
Q. Which of the following changes involves only an increase in the kinetic energy of particles without changing the substance itself?
A. Heating water from 20°C to 40°C
B. Burning a piece of paper
C. Rusting of iron
D. Digestion of food
Answer: A
Explanation:
Heating water increases the kinetic energy of its particles, making them move faster. However, water remains the same substance because no new substance is formed. This is a physical change based on particle movement rather than a chemical reaction.
Q. A student compares three samples of matter having the same volume: one solid, one liquid, and one gas. Which sample is expected to have the strongest intermolecular force?
A. Gas
B. Liquid
C. Solid
D. All have equal intermolecular force.
Answer: C
Explanation:
Particles in solids are packed very closely together and attract one another strongly. This strong intermolecular force keeps the particles in fixed positions, giving solids a definite shape and making them much less compressible than liquids or gases.
Q. Why does the smell of freshly cooked food usually spread faster than the smell of cold food?
A. Hot food produces larger particles.
B. Higher temperature increases the movement of aroma particles.
C. Cold food has no particles.
D. Warm air contains less oxygen.
Answer: B
Explanation:
Temperature affects the speed of particle movement. The aroma particles released from hot food have greater kinetic energy, so they diffuse through the air more quickly. This is why the smell reaches people faster when the food is hot.
Q. Which statement correctly explains why liquids can flow but solids cannot?
A. Liquid particles have weaker intermolecular attraction and can move past one another.
B. Solids contain no particles.
C. Liquids have stronger attraction than solids.
D. Solid particles have no mass.
Answer: A
Explanation:
In liquids, the intermolecular force is moderate, allowing particles to slide past one another while remaining close together. In solids, strong intermolecular attraction keeps particles fixed in position, preventing them from flowing under normal conditions.
Q. Which process takes place when water vapour changes into tiny droplets on the outside of a cold glass?
A. Sublimation
B. Condensation
C. Evaporation
D. Melting
Answer: B
Explanation:
Water vapour in the surrounding air loses heat when it comes into contact with the cold surface of the glass. As the particles lose kinetic energy, they move closer together and change from the gaseous state to the liquid state. This process is called condensation.
Q. Which situation best demonstrates that matter occupies space?
A. A sealed balloon becomes larger when air is pumped into it.
B. Sugar tastes sweet.
C. Iron is attracted by a magnet.
D. Water reflects sunlight.
Answer: A
Explanation:
As air is pumped into the balloon, it occupies space and pushes outward on the balloon's walls, causing it to expand. Although air is invisible, this activity proves that it is matter because it has volume and fills the available space.
Q. A science teacher asks students to identify the correct relationship between particle arrangement and the state of matter. Which option is correct?
A. Closely packed particles with strong attraction → Solid
B. Widely separated particles with strong attraction → Gas
C. Closely packed particles with weak attraction → Liquid
D. Randomly arranged particles with no movement → Gas
Answer: A
Explanation:
Solids consist of particles that are packed closely together and held by strong intermolecular forces. This arrangement gives solids a definite shape and volume. In contrast, gases have particles that are far apart and move freely because the force of attraction between them is much weaker.
Clear Concepts for Class 8 Chapter 7 Particulate Nature of Matter
Before you begin solving the MCQs, take a few minutes to revise the most important ideas from the chapter. You do not need to memorise long definitions. Instead, focus on understanding how particles behave in different situations. Once these concepts are clear, answering objective questions becomes much easier.
Matter is Everywhere Around Us
Everything you see, touch, or use is made of matter. Your school bag, a glass of water, the air you breathe, and even your notebook are examples of matter because they have mass and occupy space.
Matter exists in different forms, but one thing is common in all of them, they are made up of extremely tiny particles that cannot be seen with our eyes.
Think About It: If air cannot be seen, is it still matter? Yes. Air occupies space inside a balloon and has mass, so it is also matter.
Matter is Made of Tiny Particles
Although particles of matter are too small to be seen directly, scientists know they exist because of their behaviour.
For example:
The smell of perfume spreads throughout a room.
Sugar mixes completely with water.
Ink slowly spreads in a glass of water.
All these everyday observations happen because tiny particles are continuously moving.
Remember:
You cannot see the particles, but you can observe their effects.
Particles Never Stop Moving
One of the most important ideas in this chapter is that particles of matter are always moving. This movement never stops, even if the object appears to be still.
The speed of particle movement depends on temperature.
Heating makes particles move faster.
Cooling slows down their movement.
This is why clothes dry faster on a hot day than on a cold day.
There is Space Between Particles
Particles are not packed together completely. Small spaces exist between them, known as intermolecular spaces.
The amount of space depends on the state of matter.
- Solids have the least space.
- Liquids have more space than solids.
- Gases have the maximum space.
Because gases have large intermolecular spaces, they can be compressed much more easily than solids and liquids.
Real-Life Example:
When you pump air into a bicycle tyre, the air particles move closer together because of the large spaces between them.
Particles Attract Each Other
Particles of matter are held together by a force called the intermolecular force of attraction.
This force is:
- Very strong in solids
- Moderate in liquids
- Very weak in gases
As the force becomes weaker, particles can move more freely.
This explains why:
- A brick keeps its shape.
- Water flows easily.
- Air spreads in every direction.
Why Does Perfume Spread Across the Room?
When perfume is sprayed, its particles mix with the particles of air. Since gas particles move continuously in all directions, the fragrance spreads throughout the room without anyone carrying it.
This process is called diffusion.
Diffusion is one of the most important concepts in this chapter and is frequently tested in school examinations.
Diffusion Happens in All States of Matter
Diffusion is the movement of particles from a region of higher concentration to a region of lower concentration until they become evenly mixed.
Diffusion occurs in:
- Solids (very slowly)
- Liquids (faster)
- Gases (fastest)
The speed depends on how freely the particles can move.
Easy Way to Remember:
More particle movement = Faster diffusion.
Brownian Motion
If tiny pollen grains are observed under a microscope while floating in water, they appear to move randomly.
This continuous zigzag movement is called Brownian motion.
It happens because the pollen grains are constantly being hit by the moving water particles.
Brownian motion provides strong evidence that particles of matter are always in motion, even when we cannot see the particles themselves.
Understanding the Three States of Matter
The behaviour of particles changes in solids, liquids, and gases.
Solids
- Fixed shape
- Fixed volume
- Strong attraction between particles
- Least intermolecular space
- Difficult to compress
Liquids
- Fixed volume
- No fixed shape
- Moderate attraction
- Particles can move past one another
- Flow easily
Gases
- No fixed shape
- No fixed volume
- Weak attraction
- Maximum intermolecular space
- Easily compressed
Instead of memorising these properties, try to relate them to objects you use every day.
How Does Matter Change Its State?
Matter can change from one state to another when heat is added or removed.
Some common changes are:
Melting: Solid changes into liquid.
Freezing: Liquid changes into solid.
Evaporation: Liquid changes into gas.
Condensation: Gas changes into liquid.
Sublimation: Solid changes directly into gas without becoming a liquid.
These are physical changes because the substance remains the same; only its state changes.
Quick Revision of Class 8 Chapter 7 Particulate Nature of Matter
Use these points for a last-minute revision before your class test or examination.
- Matter is anything that has mass and occupies space.
- Matter is made up of extremely tiny particles.
- Particles of matter are always moving.
- Heating increases the movement of particles.
- Cooling decreases the movement of particles.
- There are spaces between the particles of matter.
- The spaces between particles are smallest in solids and largest in gases.
- Particles attract one another through intermolecular force.
- The force of attraction is strongest in solids and weakest in gases.
- Diffusion is the mixing of particles due to their continuous movement.
- Diffusion takes place in solids, liquids, and gases, but it is fastest in gases.
- Brownian motion is the random movement of tiny particles suspended in a liquid or gas.
- Solids have a fixed shape and fixed volume.
- Liquids have a fixed volume but no fixed shape.
- Gases have neither a fixed shape nor a fixed volume.
- Matter changes its state when heat is added or removed.
- Melting, freezing, evaporation, condensation, and sublimation are physical changes.
