Give a Reason Why – Gases Have No Definite Volume and No Definite Shape. - Chemistry

Short Note

Give a reason why –

Gases have no definite volume and no definite shape.



Any matter that is a gas has no definite volume and no definite shape. The molecules in a gas are least closely packed and intermolecular space between them is very large when compared to solids and liquids. The intermolecular force of attraction between the particles are negligible. As a result, a liquid does not easily change its shape nor they have fixed volume.

  Is there an error in this question or solution?
Chapter 1: Matter and Its Composition - Exercise


Viraf J. Dalal Class 7 New Simplified Middle School Chemistry
Chapter 1 Matter and Its Composition
Exercise | Q 8.3
Viraf J. Dalal Class 7 New Simplified Middle School Chemistry
Chapter 1 Matter and Its Composition
Objective Type Questions | Q 3.1


Which of the following are matter?

Chair, air, love, smell, hate, almonds, thought, cold, cold drink, smell of perfume.

A diver is able to cut through water in a swimming pool. Which property of matter does this observation show?

What is volume ?

Define the following terms.


Write your observation and conclusion for the following.

When a small stone is gently dipped into a glass filled with water.

Fill in the blank:

Liquids have no definite ............

Write whether the following statement is true or false.
Only water can exist in three different states.

For the following statement, say whether it describes a solid, a liquid or a gas.
Particles are far apart and move in all directions.

A substance which can change its state

  1. wood
  2. oxygen
  3. paper
  4. cloth

Fill in the blank:

The quantity of matter in an object is called its _____

What is mass ?

Give reason Gases can be compressed easily .

Name the three states of matter and define them.

Give reason of The odour of scent spreads in a room.

A solid is a state of matter that has

When sugar is dissolved in water, there is no increase in the volume. Which characteristic of matter is illustrated by this observation?

When an incense stick (agarbatti) is lighted in one corner of a room, its fragrance spreads in the whole room quickly. Which characteristic of the particles of matter is illustrated by this observation?

What is the general name of :

  1. rigid form of matter ?
  2. fluid forms of matter ?

Fill in the following blank with suitable words :

The smell of perfume gradually spreads across a room due to .....................

State two characteristics of matter demonstrated by diffusion.

In which of the following conditions, the distance between the molecules of hydrogen gas would increase?

  1. increasing pressure on hydrogen contained in a closed container
  2. some hydrogen gas leaking out of the container
  3. increasing the volume of the container of hydrogen gas
  4. adding more hydrogen gas to the container without increasing the volume of the container

When a beam of sunlight enters a room through a window, we can see tiny particles X suspended in a gas (or rather a mixture of gases) Y which are moving rapidly in a very haphazard manner.

  1. What could particles X be ?
  2. Name the gas (or mixture of gases) Y.
  3. What is the phenomenon exhibited by particles X known as ?
  4. What is causing the movement of particles X ?
  5. What conclusion does the existence of this phenomenon give us about the nature of matter ?

Define: diffusion

 Define: interconversion of states of matter.

What are the two conditions for the interconversion of states of matter?

Give reasons for the following:

Solids have a definite shape and are highly rigid while gases have to definite shape and are least rigid.

Give reasons for the following:

Sugar can be distinguished from talcum powder using water.

Give reasons for the following:

Water on freezing turns into ice.

Give reasons for the following:

A bottle of perfume on opening evolves an odour which can be sensed over a long distance.

Complete the statement given below by selecting the correct word.

The space between atoms in gases is maximum while in ____ is minimum,

Fill in the blank with the correct word Given below.

The space between atoms’ [molecules] of solids is ____

Differentiate the general properties of solids, liquids and gases in the form of a table — with reference to density.

Give a reason why –

Solids have a definite volume & a definite shape.

Describe simple experiment to show that particles of matter are closely packed in solids and less in liquids.

Fill in the blank:

Particles in a gas possess ___________ kinetic energy.

State in which of the following examples ie. a piece of wood, water, light gas is the Inter-particle space maximum.

With reference to the liquid state of matter – answer the following

State why the inter-particles attraction decreases to negligible.

Complete the blank with reference to interconversion of matter on the basis of kinetic theory-with the word ‘increase’, ‘decreases’, ‘gain’, ‘lose’, or ‘overcome’ in the following case.

During sublimation, the inter-particle attraction is _______________.

200 ml of water is poured into a bowl of 400 ml capacity. The volume of water will be ______.

Among the following ______ is not a mixture.

Water obtained from tube wells is usually ______ water.

Air is not compressible.

Match the following.

Property Example
Breaks easily (Brittle) Metal pan
Bends readily Rubber band
Can be stretched easily Cotton wool
Gets compressed easily Mud pot
Gets heated readily Plastic wire

Mr. Raghu returns home on a hot summer day and wants to have buttermilk. Mrs. Raghu has the only curd. What can she do to get buttermilk? Explain

In a glass containing some water, tamarind juice and sugar are added and stirred well. Is this a mixture? Can you tell why? Will this solution be sweet or sour or both sweet and sour?

Which one of the following element name is not derived from planet?

The Cow and Birds are nonliving things.

Mention any two characteristics of the particles of matter.

The property to flow is unique to fluids. Which one of the following statements is correct?


      Forgot password?
Use app×