Class: 6th
Subject: Physics
Chapter Title: Matter
Chapter No: 1
1a) Matter :-Matter is anything which occupies space and has mass, it can be
perceived by our senses.
For better understanding: https://youtu.be/QQsybALJoew
b) Classification of matter:-• Early Indian philosophers classified matter in the form of five basic
elements as air, earth, fire, sky and water called Panch Tatva.
• Maharshi Kannad, an Indian philosopher suggested that every matter
is made up of small particles called anu(atom) and that every anu
(atom) is composed of very small particles called parmanu
(molecule).
b) Classification of matter(contd) :-
• A molecule consisting of one atom is called monoatomic
molecule eg. Neon,argon etc
• A molecule having two atom is called diatomic molecule. eg.
Hydrogen,oxygen
• On the basis of the physical state, matter is classified as solids,
liquids and gases.
• For better understanding: https://youtu.be/68QDZAl29oE
2) Characteristics of particle of matter :-a) The particles of matter are very tiny.
b) The particles of matter have space between them.
c) The particles of matter are continuously moving.
d) The particles of matter attract each other.
a) The particles of matter are very tiny :-
Activity :- Dissolve 2 – 3 crystals of potassium permanganate in
100ml of water in a beaker. Take 10ml of this solution and dissolve in
100ml of water. Take 10ml of this solution and dissolve in 100ml of
water. Repeat this process 5 – 6 times. This shows that a few crystals of
potassium permanganate can colour a large volume of water because
there are millions of tiny particles in each crystal.
b) The particles of matter have space between them :-
The spacing between molecules of matter is called inter-molecular
space.
Activity :- Take 100 ml of water in a measuring cylinder. Dissolve
200gm salt in it with the help of a glass rod. The salt dissolves in the
water but the level of water does not change. This is because the
particles of salt get into the space between the particles of water.
c) Particles of matter are continuously moving :-
Activity :- Take a beaker fill it partly with water. Add some Iycopodium
powder in the beaker containing water. Stir it. Take out few drops of
suspension on a glass plate. Place the plate on table and illuminate it
with lamp. Observe the glass plate through a microscope. It is found
that fine particles of powder move in random pattern and their path is
as shown in fig.
d) Particles of matter attract each other :-
Activity :- Take an iron nail, a piece of chalk and a rubber band. Try
breaking them by hammering, cutting or stretching. It is more easier
to break the chalk, less easier to break the rubber band and difficult
to break the iron nail. This is because the particles in the iron nail are
held together with greater force than in the rubber band or chalk.
3) States of matter :-
Matter exists in three different states.
They are :- a) Solid b) Liquid c) Gas
For eg: Steel is solid, Oil is liquid and air is mixture of gases
For better understanding:https://youtu.be/3IW8E1YR0kE
Water can exists in all three states ice(solid state), water(liquid
state) and steam(gaseous state)
The force of attraction between the molecules of the same
substance is called the force of cohesion, while the force of
attraction between the molecules of different substance is called
force of adhesion.
Properties of States of matter:
i) Inter-molecular space
ii) Force of attraction between the molecules
iii) Movement of molecules
For better understanding: https://youtu.be/GKl7CxE6-x8
a) Properties of solids :-
i) Solids have definite shapes and fixed volume.
ii) The space between the particle is minimum.
iii) The force of attraction between the particles is maximum.
iv) The movement of the particles is minimum.
v) They are least compressible.
vi) Their rate of diffusion is least.
b) Properties of liquids :-
i) Liquids have no definite shape but have fixed volume. Liquids take
the shape of the container.
ii) The space between the particles is intermediade.
iii) The force of attraction between the particles is intermediate.
iv) The movement of the particles is intermediate.
v) They are less compressible.
vi) Their rate of diffusion is more than solids.
c) Properties of gases :-
i) Gases have no definite shape or fixed volume. Gases occupy the
whole space of the container.
ii) The space between the particles is maximum.
iii) The force of attraction between the particles is minimum.
iv) The movement of the particles is maximum.
v) They are most compressible.
vi) Their rate of diffusion is more than solids and liquids.
The change in state of matter of a substance from solid to
liquid or from liquid to gas is brought by imparting heat
energy to it at a constant temperature.
i) Change from solid state to liquid state
ii) Change from liquid state to gaseous state
For better understanding: https://youtu.be/EwzkYTfHFbo
4) Change in state of matter :-
i) Change from solid state to liquid state
• The process of changing of a substance from a solid state into
its liquid state of absorption of heat at particular temperature,
called the melting point, is called melting or fusion.
• The heat energy absorbed by the substance increases the
amplitude of vibration of molecules of the solid and the stage is
reached at the melting point when the molecules acquire
sufficient energy to overcome the force of attraction between
them and they become free to move. The solid thus changes in
liquid.
• The process of change of a substance from liquid state to
gaseous state at a particular temperature, is called the boiling
point,is called boiling or vaporisation.
• The heat energy absorbed by the substance in liquid state
increases the enery of its molecules due to which they begin to
move rapidly. Thus a liquid changes into gas.
• Melting point of ice is 0oC.
• Boiling point of water is 100oC.
ii) Change from liquid state to gaseous state
Illustration:When a solid is heated it changes into liquid. When a liquid is heated
it changes into gas.
When a gas is cooled it changes to liquid. When a liquid is cooled it
changes into solid.
Eg:- If ice is heated it changes into water. If water is heated it changes
into steam. If steam is cooled it changes into water. If water is cooled it
changes into ice.
Heat Heat
Cool Cool Solid state Liquid state Gaseous state
• https://youtu.be/68QDZAl29oE
• https://youtu.be/GKl7CxE6-x8
• https://youtu.be/QQsybALJoew
• https://youtu.be/3IW8E1YR0kE
• https://youtu.be/EwzkYTfHFbo
Useful video links: