Ch 1 - Matter in our
Surroundings (NCERT - Class 9
Ch-1) Comprehensive
Questions and Solutions
Graded A+
What is matter? - Answer: Matter is any substance that has mass and occupies space.
What is the physical nature of matter? - Answer: Matter is made up of particles, which are very-
very small.
What are the characteristics of particles of matter? - Answer: Characteristics of particles of
matter are:-
1. Particles of matter have space between them.
2. Particles of matter are continuously moving.
3. Particles of matter attract each other.
What are the three states of matter? - Answer: 1. solid,
2. liquid,
3. gas.
, Arrange Inter-particle space and Kinetic Energy in the three states of matter - Answer: The space
between the particles and kinetic energy of particles is,
Minimum in solids,
Intermediate in liquids,
Maximum in gases.
Arrange the force of attraction in the three state of matter - Answer: The force of attraction
between the particles is, Strongest in solids,
Intermediate in liquids
Weakest in gases.
What are the characteristics of solid? - Answer: Characteristics of solid states are :
(a) Have definite shape.
(b) Have definite volume.
(c) Have rigidity and incompressibility.
(d) Have distinct boundaries.
Why is rubber a solid although we can change its shape? - Answer: Rubber changes its shape
under force and regains the same shape when force is removed, so they are solid.
Why is sponge a solid although we can compress it? - Answer: A sponge has tiny holes in which
air is trapped and when we press it the air is expelled out and, we are able to compress it.
Salt and sugar take the shape of the container in which they are placed but are solid. Why? -
Answer: Salt and sugar take the shape of the container in which they are placed, but shape of
their crystals do not change, so they are solids.
Surroundings (NCERT - Class 9
Ch-1) Comprehensive
Questions and Solutions
Graded A+
What is matter? - Answer: Matter is any substance that has mass and occupies space.
What is the physical nature of matter? - Answer: Matter is made up of particles, which are very-
very small.
What are the characteristics of particles of matter? - Answer: Characteristics of particles of
matter are:-
1. Particles of matter have space between them.
2. Particles of matter are continuously moving.
3. Particles of matter attract each other.
What are the three states of matter? - Answer: 1. solid,
2. liquid,
3. gas.
, Arrange Inter-particle space and Kinetic Energy in the three states of matter - Answer: The space
between the particles and kinetic energy of particles is,
Minimum in solids,
Intermediate in liquids,
Maximum in gases.
Arrange the force of attraction in the three state of matter - Answer: The force of attraction
between the particles is, Strongest in solids,
Intermediate in liquids
Weakest in gases.
What are the characteristics of solid? - Answer: Characteristics of solid states are :
(a) Have definite shape.
(b) Have definite volume.
(c) Have rigidity and incompressibility.
(d) Have distinct boundaries.
Why is rubber a solid although we can change its shape? - Answer: Rubber changes its shape
under force and regains the same shape when force is removed, so they are solid.
Why is sponge a solid although we can compress it? - Answer: A sponge has tiny holes in which
air is trapped and when we press it the air is expelled out and, we are able to compress it.
Salt and sugar take the shape of the container in which they are placed but are solid. Why? -
Answer: Salt and sugar take the shape of the container in which they are placed, but shape of
their crystals do not change, so they are solids.
