Matter Physics Class 6 ICSE Questions and Answers

🧊 Matter Physics Class 6 ICSE Questions and Answers

ICSE Physics Chapter 1 with Detailed Solutions

Master Matter for Class 6 ICSE with comprehensive questions and answers covering the meaning of matter, states of matter, properties of solids, liquids, and gases, change of state, and the kinetic theory of matter. Each answer is explained in simple, student-friendly language for ICSE exams.

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Matter — Questions & Answers

ICSE Class 6 Physics Chapter 1

📘 Quick Reference: Matter

Matter: Anything that has mass and occupies space (volume) is called matter. Everything around us — air, water, soil, plants, animals, and even our body — is made of matter.
Examples of Matter: Book, pencil, water, air, milk, stone, tree, etc.
Three States of Matter:
- Solid: Definite shape and definite volume. Particles are tightly packed. Example: Ice, wood, iron.
- Liquid: Definite volume but no definite shape (takes the shape of the container). Particles are loosely packed. Example: Water, milk, oil.
- Gas: Neither definite shape nor definite volume. Particles are very loosely packed and move freely. Example: Air, oxygen, carbon dioxide.
Properties of Solids:
- Definite shape and volume.
- Particles are tightly packed.
- Cannot be compressed easily.
- Have high density.
- Do not flow.
Properties of Liquids:
- Definite volume but no definite shape.
- Particles are loosely packed.
- Can flow from one place to another.
- Can be compressed slightly.
- Have moderate density.
Properties of Gases:
- No definite shape or volume.
- Particles are very loosely packed.
- Can be compressed easily.
- Fill the entire container.
- Have very low density.
Change of State:
- Melting: Solid → Liquid (Ice → Water)
- Freezing: Liquid → Solid (Water → Ice)
- Evaporation: Liquid → Gas (Water → Water Vapour)
- Condensation: Gas → Liquid (Water Vapour → Water)
- Sublimation: Solid → Gas directly (Camphor → Vapour)
Kinetic Theory of Matter: All matter is made up of tiny particles (atoms and molecules) that are in constant motion. The speed of particles increases with temperature.

Key Points Summary Table:

Property	Solid	Liquid	Gas
Shape	Definite	Not definite	Not definite
Volume	Definite	Definite	Not definite
Packing	Tightly packed	Loosely packed	Very loosely packed
Compressibility	Negligible	Slight	High

💡 Study Tip

Look around you and identify the three states of matter. Water is a liquid, ice is a solid, and steam is a gas — all are the same substance in different states! Try a simple experiment: take an ice cube and watch it melt into water, then boil the water to see steam. This shows how matter can change from one state to another with temperature. Also, notice how a gas fills the entire room (like the smell of perfume spreading), while a solid like a book keeps its shape. Understanding these differences will help you master this chapter.

Question 1

What is matter?

✅ Answer:

Matter is anything that has mass and occupies space (volume).

Question 2

Name the three states of matter.

✅ Answer:

The three states of matter are solid, liquid, and gas.

Question 3

Which state of matter has a definite shape and volume?

✅ Answer:

Solid has a definite shape and volume.

Question 4

Which state of matter has a definite volume but no definite shape?

✅ Answer:

Liquid has a definite volume but no definite shape.

Question 5

Which state of matter has neither definite shape nor definite volume?

✅ Answer:

Gas has neither definite shape nor definite volume.

Question 6

Give two examples of solids.

✅ Answer:

Ice and wood are two examples of solids.

Question 7

Give two examples of liquids.

✅ Answer:

Water and milk are two examples of liquids.

Question 8

Give two examples of gases.

✅ Answer:

Oxygen and carbon dioxide are two examples of gases.

Question 9

What is melting?

✅ Answer:

Melting is the process in which a solid changes into a liquid on heating.

Question 10

What is freezing?

✅ Answer:

Freezing is the process in which a liquid changes into a solid on cooling.

Question 11

What is evaporation?

✅ Answer:

Evaporation is the process in which a liquid changes into a gas at any temperature.

Question 12

What is condensation?

✅ Answer:

Condensation is the process in which a gas changes into a liquid on cooling.

Question 13

What is sublimation?

✅ Answer:

Sublimation is the process in which a solid changes directly into a gas without becoming a liquid.

Question 14

Give one example of sublimation.

✅ Answer:

Camphor changes directly into gas on heating — an example of sublimation.

Question 15

Why do solids have a definite shape?

✅ Answer:

Solids have a definite shape because their particles are tightly packed and cannot move freely.

Question 16

Why do liquids flow?

✅ Answer:

Liquids flow because their particles are loosely packed and can move past each other.

Question 17

Why can gases be compressed easily?

✅ Answer:

Gases can be compressed easily because their particles are very loosely packed with large spaces between them.

Question 18

What happens to the particles of matter when heated?

✅ Answer:

When heated, the particles of matter gain energy and move faster, causing expansion.

Question 19

What is the kinetic theory of matter?

✅ Answer:

The kinetic theory of matter states that all matter is made up of tiny particles that are in constant motion.

Question 20

What is the difference between evaporation and boiling?

✅ Answer:

Evaporation occurs at any temperature, while boiling occurs at a specific temperature (boiling point).

Question 21

What is the boiling point of water?

✅ Answer:

The boiling point of water is 100°C at normal atmospheric pressure.

Question 22

What is the melting point of ice?

✅ Answer:

The melting point of ice is 0°C.

Question 23

Why does water take the shape of its container?

✅ Answer:

Water takes the shape of its container because its particles can move freely and are not fixed in position.

Question 24

What happens when a gas is cooled?

✅ Answer:

When a gas is cooled, it condenses and changes into a liquid.

Question 25

Name the process of changing a liquid into a solid.

✅ Answer:

The process of changing a liquid into a solid is called freezing.

Question 26

What is the space between particles of matter called?

✅ Answer:

The space between particles of matter is called interparticle space.

Question 27

Why is a gas highly compressible?

✅ Answer:

A gas is highly compressible because it has large interparticle spaces between its particles.

Question 28

What is the effect of temperature on the states of matter?

✅ Answer:

Temperature affects the speed of particles and can change the state of matter (e.g., heating causes melting, cooling causes freezing).

Question 29

Give an example of condensation from daily life.

✅ Answer:

Water droplets on the outside of a cold glass are an example of condensation.

Question 30

Name one substance that can exist in all three states of matter.

✅ Answer:

Water can exist as a solid (ice), liquid (water), and gas (water vapour).

Question 1

What is matter? Give three examples.

✅ Answer:

Matter is anything that has mass and occupies space.

Examples: Book, water, air.

Question 2

Describe the three states of matter with examples.

✅ Answer:

Solid: Definite shape and volume; particles tightly packed. Example: Ice, wood.

Liquid: Definite volume but no definite shape; particles loosely packed. Example: Water, milk.

Gas: No definite shape or volume; particles very loosely packed. Example: Air, oxygen.

Question 3

What are the properties of solids?

✅ Answer:

Properties of solids:

Definite shape and volume.
Particles are tightly packed.
Cannot be compressed easily.
Have high density.
Do not flow.

Question 4

What are the properties of liquids?

✅ Answer:

Properties of liquids:

Definite volume but no definite shape.
Particles are loosely packed.
Can flow from one place to another.
Can be compressed slightly.
Have moderate density.

Question 5

What are the properties of gases?

✅ Answer:

Properties of gases:

No definite shape or volume.
Particles are very loosely packed.
Can be compressed easily.
Fill the entire container.
Have very low density.

Question 6

Explain the change of state with examples.

✅ Answer:

Change of state occurs when matter changes from one state to another due to heating or cooling.

Examples:

Melting: Ice → Water
Freezing: Water → Ice
Evaporation: Water → Water Vapour
Condensation: Water Vapour → Water
Sublimation: Camphor → Vapour

Question 7

What is the difference between evaporation and condensation?

✅ Answer:

Evaporation: Liquid changes into gas on heating. Example: Water drying up.

Condensation: Gas changes into liquid on cooling. Example: Water droplets on a cold glass.

Question 8

Why do solids have a fixed shape but liquids do not?

✅ Answer:

Solids have a fixed shape because their particles are tightly packed and cannot move from their positions. Liquids do not have a fixed shape because their particles are loosely packed and can move freely, taking the shape of the container.

Question 9

Why can gases be compressed easily but solids cannot?

✅ Answer:

Gases can be compressed easily because they have large interparticle spaces between their particles. Solids cannot be compressed because their particles are tightly packed with almost no space between them.

Question 10

What is the kinetic theory of matter?

✅ Answer:

The kinetic theory of matter states that:

All matter is made up of tiny particles (atoms and molecules).
These particles are in constant motion.
The speed of particles increases with temperature.

Question 11

What happens when a solid is heated?

✅ Answer:

When a solid is heated:

Its particles gain energy and vibrate faster.
At the melting point, the solid changes into a liquid.
Example: Ice melts into water at 0°C.

Question 12

What happens when a gas is cooled?

✅ Answer:

When a gas is cooled:

Its particles lose energy and slow down.
At the condensation point, the gas changes into a liquid.
Example: Water vapour condenses into water droplets.

Question 13

What is sublimation? Give two examples.

✅ Answer:

Sublimation is the process in which a solid changes directly into a gas without becoming a liquid.

Examples:

Camphor changes directly into gas.
Dry ice (solid carbon dioxide) changes directly into gas.

Question 14

What is the difference between boiling and evaporation?

✅ Answer:

Boiling: Occurs at a specific temperature (boiling point) throughout the liquid. Example: Water boils at 100°C.

Evaporation: Occurs at any temperature only from the surface of the liquid. Example: Water drying up from a wet cloth.

Question 15

Why does the smell of perfume spread across a room?

✅ Answer:

The smell of perfume spreads across a room because the particles of perfume gas diffuse into the air. The particles move rapidly and mix with the air particles, spreading throughout the room.

Question 16

What is diffusion? Give one example.

✅ Answer:

Diffusion is the process of mixing of particles of one substance with the particles of another substance due to their constant motion.

Example: The smell of food spreads throughout the house.

Question 17

What is the effect of heating on the volume of a substance?

✅ Answer:

When a substance is heated, its volume increases (expansion) because the particles gain energy and move apart. This is called thermal expansion.

Question 18

What is the effect of cooling on the volume of a substance?

✅ Answer:

When a substance is cooled, its volume decreases (contraction) because the particles lose energy and come closer together. This is called thermal contraction.

Question 19

Why does a wet cloth dry faster in the sun?

✅ Answer:

A wet cloth dries faster in the sun because heat increases the rate of evaporation. The water particles gain energy and change into water vapour quickly.

Question 20

What are the characteristics of particles of matter?

✅ Answer:

Characteristics of particles of matter:

They are very small.
They have interparticle space between them.
They are in constant motion.
They attract each other.

Question 1

What is matter? Explain the three states of matter with their properties and examples.

✅ Answer:

Matter:
Matter is anything that has mass and occupies space. Everything around us is made of matter.

Three States of Matter:

1. Solid:

Properties: Definite shape, definite volume, tightly packed particles, cannot be compressed easily, high density, do not flow.
Examples: Ice, wood, iron, stone.

2. Liquid:

Properties: Definite volume but no definite shape (takes the shape of the container), loosely packed particles, can flow, can be compressed slightly, moderate density.
Examples: Water, milk, oil, juice.

3. Gas:

Properties: No definite shape or volume, very loosely packed particles, can be compressed easily, fill the entire container, very low density.
Examples: Air, oxygen, carbon dioxide, water vapour.

Conclusion:
The three states of matter differ in the arrangement and movement of their particles. These differences give them their unique properties.

Question 2

Explain the change of state in matter with examples. What causes these changes?

✅ Answer:

Change of State:
Matter can change from one state to another when heat is added or removed. This is called change of state.

Types of Change of State:

1. Melting (Solid → Liquid):

When a solid is heated, it changes into a liquid.
Example: Ice melts into water at 0°C.

2. Freezing (Liquid → Solid):

When a liquid is cooled, it changes into a solid.
Example: Water freezes into ice at 0°C.

3. Evaporation (Liquid → Gas):

When a liquid is heated, it changes into a gas.
Example: Water changes into water vapour.

4. Condensation (Gas → Liquid):

When a gas is cooled, it changes into a liquid.
Example: Water vapour condenses into water droplets.

5. Sublimation (Solid → Gas directly):

When a solid is heated, it changes directly into a gas without becoming a liquid.
Example: Camphor changes into vapour.

Cause of Change of State:
Change of state is caused by:

Heating: Increases the energy of particles, causing them to move faster and break free from their fixed positions.
Cooling: Decreases the energy of particles, causing them to slow down and come closer together.

Question 3

What is the kinetic theory of matter? Explain how it explains the properties of solids, liquids, and gases.

✅ Answer:

Kinetic Theory of Matter:
The kinetic theory of matter states that:

All matter is made up of tiny particles (atoms and molecules).
These particles are in constant motion.
The speed of particles increases with temperature.
There are spaces between particles (interparticle space).
Particles attract each other.

Explanation of Properties:

1. Solids:

Particles are tightly packed and can only vibrate in their fixed positions.
This gives solids a definite shape and volume.
They cannot be compressed because there is very little space between particles.

2. Liquids:

Particles are loosely packed and can move past each other.
This gives liquids a definite volume but no definite shape.
They can flow and take the shape of the container.

3. Gases:

Particles are very loosely packed and move freely at high speeds.
This gives gases no definite shape or volume.
They can be compressed easily because there is large space between particles.

Conclusion:
The kinetic theory explains why different states of matter have different properties based on the arrangement and movement of their particles.

Question 4

Describe an activity to show that particles of matter are in constant motion.

✅ Answer:

Activity: Particles of Matter are in Constant Motion (Diffusion)

Materials needed:

A glass of water
A few drops of ink

Procedure:

Fill a glass with clean water.
Add a few drops of ink to the water.
Observe what happens.

Observation:

The ink spreads throughout the water slowly.
After some time, the entire water becomes coloured.

Conclusion:
The spreading of ink in water shows that the particles of ink are in constant motion and mix with the particles of water. This process is called diffusion.

Another Example:
The smell of perfume spreading across a room also shows that particles of matter are in constant motion.

Question 5

Explain the process of evaporation and condensation with examples from daily life.

✅ Answer:

Evaporation:
Evaporation is the process in which a liquid changes into a gas at any temperature. It occurs only from the surface of the liquid.

How it happens:

Particles at the surface of the liquid gain energy from the surroundings.
They escape into the air as gas.

Examples from Daily Life:

Wet clothes drying in the sun.
Water in a pond drying up during summer.
Water in a clay pot becoming cool due to evaporation.
Petrol evaporating from a spilled drop.

Condensation:
Condensation is the process in which a gas changes into a liquid on cooling.

How it happens:

Gas particles lose energy when cooled.
They slow down and come closer together.
They change into liquid.

Examples from Daily Life:

Water droplets on the outside of a cold glass of water.
Dew drops on grass in the early morning.
Fog on a mirror after a hot shower.
Rain formation in the water cycle.

Conclusion:
Evaporation and condensation are opposite processes. Together, they play an important role in the water cycle.

Question 6

What is the difference between solids, liquids, and gases? Explain with examples.

✅ Answer:

Differences between Solids, Liquids, and Gases:

Property	Solid	Liquid	Gas
Shape	Definite	Not definite	Not definite
Volume	Definite	Definite	Not definite
Packing of Particles	Tightly packed	Loosely packed	Very loosely packed
Compressibility	Negligible	Slight	High
Flow	Do not flow	Can flow	Flow easily
Density	High	Moderate	Very low

Examples:

Solid: Ice, wood, iron, stone.
Liquid: Water, milk, oil, juice.
Gas: Air, oxygen, carbon dioxide, water vapour.

Question 7

What is diffusion? Explain with examples. Why is diffusion faster in gases than in liquids?

✅ Answer:

Diffusion:
Diffusion is the process of mixing of particles of one substance with the particles of another substance due to their constant motion.

Examples of Diffusion:

The smell of perfume spreading across a room.
The smell of food spreading throughout the house.
Ink spreading in water.
Oxygen from the air dissolving in water (for fish to breathe).

Why Diffusion is Faster in Gases:
Diffusion is faster in gases than in liquids because:

Gas particles are very loosely packed with large spaces between them.
Gas particles move at very high speeds.
Liquid particles are more closely packed and move more slowly.

Conclusion:
Diffusion is an important process that helps in the exchange of gases and the spreading of smells. It is faster in gases due to the large spaces and high speed of gas particles.

Question 8

Explain the effect of heating and cooling on matter with examples.

✅ Answer:

Effect of Heating on Matter:

When matter is heated:

Particles gain energy and move faster.
The space between particles increases.
The substance expands (volume increases).
This is called thermal expansion.

Examples:

Ice melts into water on heating.
Water boils and changes into steam.
Metals expand on heating (used in thermometers).

Effect of Cooling on Matter:

When matter is cooled:

Particles lose energy and slow down.
The space between particles decreases.
The substance contracts (volume decreases).
This is called thermal contraction.

Examples:

Water freezes into ice on cooling.
Water vapour condenses into water droplets.
Metals contract on cooling (used in fitting iron rims on wooden wheels).

Conclusion:
Heating and cooling cause changes in the state and volume of matter. These changes are due to the change in the energy and movement of particles.

Question 9

What are the characteristics of particles of matter? Explain each with an example.

✅ Answer:

Characteristics of Particles of Matter:

1. Particles are Very Small:

Particles of matter are extremely tiny and cannot be seen with the naked eye.
Example: A drop of water contains millions of water molecules.

2. Particles Have Space Between Them (Interparticle Space):

There are empty spaces between particles.
Example: Sugar dissolves in water and occupies the space between water particles.

3. Particles are in Constant Motion:

Particles of matter are always moving.
Example: The smell of perfume spreads across a room due to the motion of particles.

4. Particles Attract Each Other:

Particles of matter attract each other with a force called interparticle force.
Example: Solids have strong interparticle forces, which is why they have a fixed shape.

Conclusion:
These characteristics explain the different properties of solids, liquids, and gases.

Question 10

Explain the water cycle with the help of the processes of evaporation and condensation.

✅ Answer:

Water Cycle:
The water cycle is the continuous movement of water between the Earth's surface and the atmosphere through evaporation and condensation.

Steps of the Water Cycle:

1. Evaporation:

Water from oceans, rivers, and lakes evaporates due to the heat of the sun.
Water changes into water vapour and rises into the atmosphere.

2. Condensation:

As the water vapour rises, it cools down at higher altitudes.
It condenses to form tiny water droplets, which form clouds.

3. Precipitation:

When the clouds become heavy, the water droplets fall back to the Earth as rain, snow, or hail.

4. Collection:

The water collects in rivers, lakes, and oceans, and the cycle repeats.

Importance of the Water Cycle:

It maintains the balance of water on Earth.
It provides fresh water for drinking and agriculture.
It regulates the Earth's temperature.

Conclusion:
The water cycle is a continuous process powered by the sun. Evaporation and condensation are the key processes that drive it.

📘 Quick Revision: Matter

Matter: Anything that has mass and occupies space.
Three States: Solid, Liquid, Gas.
Solid: Definite shape and volume; particles tightly packed.
Liquid: Definite volume, no definite shape; particles loosely packed.
Gas: No definite shape or volume; particles very loosely packed.
Change of State: Melting, Freezing, Evaporation, Condensation, Sublimation.
Kinetic Theory: Matter is made of tiny particles in constant motion.
Diffusion: Mixing of particles of one substance with another.
Heating: Causes expansion and change of state.
Cooling: Causes contraction and change of state.