Class-9
Chapter-1
Matters in our surroundings.
1) What is matter?
Ans.
Matter is anything that occupied space that have mass and volume and
offer residence is called matter.
OR......
Matter is anything that occupies mass and
volume.
OR.....
We can say that anything that has
occupies space and mass of can be felt by our one or more sense organ is called
matter.
NOTE-
1. The SI unit of mass is kilogram (kg).
2. The SI unit of volume is cubic meter
(m3).
3. The common unit of measuring volume is
litre (L).
(1L=1dm3, 1L=1000mL, 1mL= 1cm3)
For example-
Full form:
1. MKS- Metre Kilogram Second
2. CGS- Centi Gram Second
3. FPS- Foot Pound Second
Classification of matter-
1. Solid
2. Liquid
3. Gas
Solid- solid has definite shape and
volume.
Liquid- Liquid has definite volume but
not definite shape.
Gas- Gas has neither definite shape nor
definite volume.
Characteristics of matter-
Some important Characteristics of
particles of matter are-
1. Particle of matter has space between
them.
2. Particle of matter are in the state of
continues moment.
3. Particles of matter attract each
other.
4. The particle of matter has a tendency
of defuse, i.e. to intermise on their own with each other.
States of matter-
Matter around us exists in
different states which are solid, liquid and gas.
These states of matter arise due to the variation in the characteristic
of particle of matter.
Solid state- solid is define as that form
of matter which pass us rigidity, incompressibility, and hence, as a definite
shape and definite volume.
Solid state
Properties- some important properties of
solid are as follows-
Solid have definite shape and
fixed volume.
I.e. have negligible compressibility.
Solids either
do not defuse.
Solids may
break under force.
Solids have a
tendency to maintain their shape when subjected to outside force.
Solids have
higher densities compare the liquids and gases.
For example- sugar, sand, rock, stone,
metals like iron, copper, aluminium, gold, silver etc. Are the example of
substance which exists in solid state.
Liquid state- Liquid is define as that
form of matter which posses of fixed volume but have no fixed shape.
Liquid state
Properties-
Some important property of liquids is as follows:
1. Liquids do not have definite shape but
they have definite volume.
2. Solid, liquids and gas can defuse into
liquid.
4. Liquid flows and changes shape. So
that is not tight. So they can be called fluid.
5. Liquids are almost incompressible.
6. Density of liquids is less than that
of its solid form.
Gaseous state- Gases can be defined or
that form of matter while passes high compressibility and hence, has neither
definite volume.
Gaseous state
Properties-
Some important properties of gases are as
follows:
1. Gases do not have definite shape and
definite volume.
2. Gases are highly compressible.
3.In gaseous state the particles of move
independently at high speed.
Example- air, oxygen, carbon dioxide,
nitrogen, etc.
5.Gases show the property of diffusing
very fast into other gases due to high speed of particle.
6.The density of gases is minimum.
Inter conversion state of matter-
The state are inter convergionable. This
phenomenon of change of matter from one state to another state and back to its original
state by altering the condition of temperature and pressure is called inter
conversion of state of matter.
Terms involved in change of state of
matter-
Followings terms involved in change of
state of matter-
1.
Fusion or melting and melting
point.
2.
Boiling and boiling point
3.
Sublimation
4.
Vaporisation
5.
Freezing and freezing point
6.
Condensation
1)Fusion or melting and melting point-
The process of conversion of matter from its solid state to its liquid state at
specific condition of temperature and pressure is called Fusion or melting.
The definite temperature at which
a solid starts melting is called the melting point of solid.
Example –The
melting point of ice is 0oC or 273.16K
2) Boiling and boiling point- The process
of conversion of matter from its liquid state to its vapour state at specific
condition of temperature and pressure is called boiling.
The
definite temperature at which a liquid convert into vapour state is called
boiling point.
3) Sublimation- The process of change
solid state directly into gaseous state is called sublimation.
Example- camphor, iodine,
etc.
4) Vaporisation- The process of
conversion of matter from its liquid state to its gaseous state at specific
condition of temperature and pressure is called vaporisation.
5) Freezing - The process of conversion
of matter from its liquid state to its solid state at specific condition of
temperature and pressure is called freezing.
It is
the reverse process of melting.
The definite temperature at which a liquid starts freezing is called the
melting point of freezing point.
6) Condensation- The process of
conversion of matter from its gaseous state to its liquids state at specific
condition of temperature and pressure is called freezing.
Effect of change of temperature:
The effect of change of temperature at physical state may be summarised as:
So, it can be concluded that the state of
matter can be changed into another by changing the temperature.
Scale of measuring temperature-
There are three scales of measuring
temperature-
1. Celsius
2. Fahrenheit
3. Kelvin
1. Temperature on Kelvin scale= (temperature
of oC + 273.16 or 273)
T(K)=T(OC)+273.16
OR 273
The SI unit of temperature is Kelvin and
it is denoted by K.
2. T(OC)=
T(K)-273.16 OR 273
3. T(OF)-T(OC) AND OF Temprature are related to each other by the relation.
NUMERICALS-
1. Convert the
temperature of 200oC into Kelvin scale.
Solution- we know that
T(K)= T(OC)+273.16
T(K)= (200+273.16)K
= 473.16K
2.
Convert the temperature of 450K into Celsius scale.
Solution-
- we know that
T(OC)=
T(K)+273.16
T(OC)=
(200+273.16) OC
= 176.84
OC
NCERT EXERCISES-
1. Convert the following temperature to
the Celsius scale-
i. 293K
T(OC)= T(K)+273
=(293-273)oC
=20oC
ii. 470K
T(OC)= T(K)+273
=470-273
=197oC
2. Convert the following temperature to
the Kelvin scale-
i. 25oC
T(K)= T(OC)+273
(25+273)K
293K
ii. 373OC
T(K)= T(OC)+273
(373+273)K
646K
3. Give reason for the following
observations-
i. Naphthalene balls disappear with time
without leaving any solid.
Ans. Naphthalene balls keep on forming
naphthalene vapours which slowly disappear into the air.
ii. We can get the smell of perfume
sitting several meters away-
Ans. Due to the fast diffusion of the gaseous particles of the air perfume
through air.
4. Arrange the following substance in
increasing order of forces of attraction between particles- water, sugar,
oxygen
Ans. Oxygen < water < sugar
5. What is the physical state of water
at-
i. 25oC
liquid state
ii. 0 oC
solid or liquid state
iii. 100 oC
gas or liquid state
6. Give to reasons to justify
i. Water at room temperature is a liquid.
Ans.
1) It has tendency to flow.
2) It takes the shape of the vocal card in which it kept.
ii. An iron almirah is solid at room
temperature.
Ans. 1) It is hard and rigid.
2) It has fixed shape and volume.
7. Why is ice at 273K more effective than
in cooling than water at the same temperature.
Ans. Because water does not absorb energy
from the sorroundings.
8.
What produces more sever burn, boiling, water or steam?
Ans. The reason is that releases the
extra amount of heat during vaporisation which it has already taken.
9.
Name A,B,C,D,E and F in the following diagram showing change in its state-
A. Melting
B. Vaporisation
C.
Condensation
D. Freezing
E. Sublimation
F.
Solidification
Quantitiy
|
Unit
|
Symbol
|
Temperature
Length
Mass
Weight
Volume
Density
pressure
|
Kelvin
Meter
Kilogram
Newton
Cubic meter
Kilogram per cubic meter
pascal
|
K
M
Kg
W
m3
Kg m-3
Pa
|
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