1.
What Is Matter?
Matter is everything around you. Atoms and molecules are all
composed of matter. Matter is anything that has mass and
takes up space.
Matter can be classified on the basis of chemical and physical
properties. On the basis of physical properties matter can be
classified into solids, liquids and gasses. And on the basis of
chemical properties matter is classified as elements, mixtures
and compounds. We will study about the classification of
matter on the basis of physical properties.

2.
Physical Nature of Matter
Matter is made up of very tiny particles
Matter is made up of tiny pieces or particles. Our galaxy is
made up of particles, Our planet is made up of particles and
our body is also made up of particles.
Particles of Matter are very very small
The number of particles in everything is very, very small. For
e.g., a small rain drop contains about
1,000,000,000,000,000,000,000 particles of water in it! The
particles of matter are so small that we cannot see them with a
high power microscope. Even without seeing them, we have
certain evidence which tells us that all the things is made of
tiny particles.

3.
Characteristics of Matter
• Particles of matter have spaces between
them
• Particles of matter are constantly moving
• Particles of matter attract each other.

4.
Particles of matter have spaces between
them
Let us look at the level of sugar solution in the beaker. We will find that level
of sugar solution in the beaker Is at the same mark where water level was
initially in the beaker. This means that even after dissolving 50 grams in
sugar in 100 ml of water, the volume has not increased. This can be
explained by assuming that the particles of water have some spaces
between them.
When sugar is dissolved in water, its crystals separate into very fine
particles. These particles of sugar go into the spaces between the various
particles of water due to which there is no change in the volume of water on
dissolving sugar in it. The fact there is no change in volume on dissolving
sugar in water is tell us that there are spaces between the particles of water.
• Take a 100 ml beaker.
• Fill half the beaker with water and
mark the level of water.
• Dissolve some salt/ sugar with the help
of a glass rod.
The spaces between the particles can be shown by performing these activities

5.
Particles of matter are constantly
moving
Explanation
When the crystals of copper are placed at the bottom of a beaker containing water, then
water un the whole beakers turns blue slowly. This can be explained on the basis of motion
of copper sulphate particles and water particles as follows . The crystals of copper sulphate
dissolve in a little of water around them to form fine particles of clear water are also
moving. Due to the motion of their particles, the blue copper sulphate particles in solution
move upwards in the beaker and the colourless water particles move downwards and mix
with each other . This is called diffusion. This diffusion of copper sulphate particles in water
turns blue. Thus, the spreading of blue colour of copper sulphate crystals in water is due to
the movement of particles of copper sulphate as well as water particles.
Activity
• Drop a crystal of copper sulphate or potassium permanganate into a glass of hot
water and another containing cold water. Do not stir the solution. Allow the crystals
to settle at the bottom.
• What do you observe just above the solid crystal in the glass?
• What happens as time passes?
• What does this suggest about the particles of solid and liquid?
• Does the rate of mixing change with temperature? Why and how?

6.
Particles of matter attract each
other
This can be shown by performing these activities
Activity 1
• Take an iron nail, a piece of chalk and a rubber band.
• Try breaking them by hammering, cutting or stretching.
• In which of the above three substances do you think the particles are held
together with greater force?
Activity 2
• Open a water tap, try breaking the stream of water with your fingers.
• Were you able to cut the stream of water?
• What could be the reason behind the stream of water remaining together?
Explanation
The above three activities suggest that particles of matter have force acting
between them. This force keeps the particles together. The strength of this
force of attraction varies from one kind of matter to another.

7.
States of matter
On the basis of physical states, all the matter
can be classified into three groups: Solids,
Liquids and Gasses. For example:
i) Sugar, Sand, Iron, Wood, Rocks etc.
ii) Water, Milk, Petrol, kerosene etc.
iii) Air, Oxygen, Steam etc.

8.
Properties Of Solids
The solids have the following characteristic properties:
• Have a fixed shape and a fixed volume.
• Cannot be compressed much.
• Have high density.

9.
Properties Of Liquids
The liquids have following characteristics properties:
• Have a fixed shape but they don't have no fixed shape.
• Cannot be compressed.
• Generally flow easily.

10.
Properties Of Gasses
The gasses have following characteristics properties:
• Have neither a fixed shape nor fixed volume.
• Gasses have very low density.
• Can be compressed easily.

11.
Why Solids, Liquid, Gasses Have
Different Properties
Matter in all three states, liquids, gasses and solids is made up of very small
particles. As we have read above, the particles of matter are in continuous
motion. Some forces of attraction tend to hold the particles of matter. The
forces of attraction tend to hold the particles together and control there
movements. The interparticle forces of attraction are the maximum when the
particles are together. As the distance between the particles increase, the force
of attraction decreases. The movement of particles can be changed by heating
the matter. Higher the temperature, greater is the movement of particles. We
can now say that the following properties of particles determine the physical
state of matter. That is, the following properties of particles which decide
whether the substance is solid, gas or liquid:
1. Spaces between the particles . Spaces between the particles is minimum in
solids, maximum in gasses and intermediate in liquids.
2. The force of attraction between particles. The forces of attraction
between the particles are the strongest in solids , less strong in liquids and
negligible in gasses.
3. The amount of particles. The movement of particles is the minimum in
solids, intermediate in liquid an maximum in gasses

12.
Interconversion of the three states of
matter
Gas
Liquid
Solid
Sublimation
Sublimation
What would it take for matter to move
from one state to another?

13.
Effect Of Change Of Temperature
By increasing temperature a solid can be converted into
liquid state and the liquid can be converted into gaseous
state. And by decreasing the temperature gas can be
converted into liquid and liquid can be converted into solid.
On increasing the temperature of solids, the kinetic energy
of the particles increases. Due to the increase in kinetic
energy, the particles start vibrating with greater speed. The
energy supplied by heat overcomes the forces of attraction
between the particles. The particles leave their fixed
positions and start moving more freely. A stage is reached
when the matter in solid form changes into liquid or matter
in liquid form changes into gas.

14.
Melting (Fusion)
When a solid is heated, the particles begin to vibrate
with greater speed and begin to move more freely. Then
at a particular temperature the solid melts and changes
into liquid. The process of melting is also known as
fusion. The temperature at which a solid melts is called
its melting point. The melting point of ice is 0C or 273 K.
Latent heat of fusion
The amount of heat energy required to change 1kg of a
solid into liquid at atmospheric pressure at its melting
point is called the latent heat of fusion.

15.
Solidification
The process of changing of liquid into solid is
known as solidification. It is an exothermic*
process.
For e.g. when temperature of water is bring
brought below 0C.
Exothermic- accompanied by the release of heat

16.
Boiling
When a liquid is heated, its particles begin to move even
faster. Then at a particular temperature the liquid begins to
boil and changes into gas (vapor).Boiling is a bulk
phenomenon. When a liquid boils the bulk of the liquid
changes into vapor. The temperature at which a liquid
starts boiling is called its boiling point. The boiling point of
water is 1000C or 373K ( 273 + 100).
Latent heat of vaporization
The amount of heat energy required to change 1kg of a
liquid into gas at atmospheric pressure at its boiling point
is called the latent heat of vaporization.

17.
Condensation
• It is the process Of converting a vapor into
liquid state, upon decrease in temperature
of the vapor. It is also known as exothermic
process.
• For e.g.- Phenomenon of formation of water
droplets on any cold surface.

18.
Sublimation
A change of state directly from solid to gas without
changing into liquid state (or vice versa) is called
sublimation.
E.g. :-
If solid camphor or ammonium chloride is heated, it
changes into vapor.
If the vapors are cooled it changes into solid.

19.
Effect of Pressure on Gasses
When pressure is applied on gas the particles come closer and
the gas changes into liquid.
We can liquefy gases by applying pressure and reducing the
temperature. Compressed solid carbon dioxide is called dry
ice. If the pressure is reduced it changes directly to gas without
coming into liquid state. So solid carbon dioxide is known as
dry ice.

20.
Evaporation
The change of a liquid into vapor at any temperature
below its boiling point is called evaporation.
Evaporation is a surface phenomenon. Particles from
the surface gain enough energy to overcome the
forces of attraction and changes to vapor state.

21.
Evaporation vs. Boiling
Boiling
• Evaporation is a process in
which the liquid gets
converted into its gaseous
form at any temperature
below it's boiling point .
• evaporation takes place at
any temperature.
• evaporation is a surface
phenomenon.
• Evaporation is slow process .
• rate of evaporation depends
on surface area
Evaporation
• boiling is the process in
which liquid gets converted
into gaseous state.
• boiling process has a fixed
temperature.
• boiling is a bulk
phenomenon.
• boiling is a rapid or fast
process.
• rate of boiling depends on
the amount of heat

22.
Factors Affecting Evaporation
• The rate of evaporation depends upon surface
area, temperature, humidity and wind speed.
• Increase in the surface area increases the rate of
evaporation.
• Increase in temperature increases the rate of
evaporation.
• Increase in humidity decreases the rate of
evaporation.
• Increase in wind speed increases the rate of
evaporation.

23.
How Does Evaporation Cause
Cooling?
When a liquid evaporates, the particles of the liquid
absorb heat from the surroundings and evaporates. So
the surroundings become cold.
E.g. :- People sprinkle water on the roof or open ground
because during evaporation water absorbs heat makes
the hot surface cool.
During summer we sweat more because during
evaporation the sweat absorbs heat from our body
making the body cool.
Wearing cotton clothes in summer keeps us cool
because cotton absorbs sweat and when the sweat
evaporates it absorbs heat from our body making the
body cool.

24.
Now scientists are talking of five
states of matter: Solid, Liquid, Gas,
Plasma and Bose Einstein
Condensate.

25.
Plasma
It takes a very special environment to keep plasmas going. They are
different and unique from the other states of matter. Plasma is different
from a gas, because it is made up of groups of positively and negatively
charged particles. In neon gas, the electrons are all bound to the nucleus. In
neon plasma, the electrons are free to move around the system.
are cold compared to really hot stars. However, they are still both forms of
plasma, even with the different physical characteristics.
Plasmas are a lot like gases, but the
atoms are different, because they are
made up of free electrons and ions of
an element such as neon (Ne). You
don't find naturally occurring plasmas
too often when you walk around. They
aren't things that happen regularly on
Earth.

26.
Finding a Plasma
While natural plasmas aren't found around you that often, man-made
plasmas are everywhere. Think about fluorescent light bulbs. They are not
like regular light bulbs. Inside the long tube is a gas. Electricity flows through
the tube when the light is turned on. The electricity acts as an energy source
and charges up the gas. This charging and exciting of the atoms creates
glowing plasma inside the bulb. The electricity helps to strip the gas
molecules of their electrons.
Another example of plasma is a neon sign. Just like a fluorescent lights, neon
signs are glass tubes filled with gas. When the light is turned on, the
electricity flows through the tube. The electricity charges the gas and creates
plasma inside of the tube. The plasma glows a special color depending on
what kind of gas is inside. Inert gases are usually used in signs to create
different colors. Noble gases such as helium (He), Neon (Ne), Argon (Ar), and
Xenon (Xe) are all used in signs.
You also see plasma when you look at stars. Stars are big balls of gases at
really high temperatures. The high temperatures charge up the atoms and
create plasma. Stars are a good example of how the temperature of plasmas
can be very different. Fluorescent lights are cold compared to really hot stars.
However, they are still both forms of plasma, even with the
different physical characteristics.

27.
Bose-Einstein Condensate
The Bose-Einstein state of matter was the only one created while your parents
were alive. In 1995, two scientists, Cornell and Weiman, finally created the
condensate. When you hear the word condensate, think
about condensation and the way gas molecules come together and condense
and to a liquid. The molecules get denser or packed closer together.
Two other scientists, Satyendra Bose and Albert Einstein, had predicted it in the
1920s, but they didn't have the equipment and facilities to make it happen at
that time. Now we do. If plasmas are super hot and super excited atoms, the
atoms in a Bose-Einstein condensate (BEC) are total opposites. They are super
unexcited and super cold atoms.