COMET: It is exciting
to see a comet in the night sky. A comet is not a star.
It is a
rock made of dust and ice. The long tail
is seen because, as the comet comes near the
Sun, the ice melts and reflects
the light
of the Sun.
The tail
of the comet is seen
in the opposite
direction
of the Sun. The tail
of the comet appears because minute
particles
from the Sun strike
the gaseous part emitted
from the comet. Now it is clear
that the Solar family
consists
of the Sun, its eight
planets,
the satellites
like the
moon that revolve
around the planets,
dwarf planets,
thousands of asteroids,
meteoroids
and

comets.

UNIVERSE: Millions
of constellations
of stars seen in the sky is called
a galaxy.
Thousands of galaxies
form the Universe.
The Universe
is vast and ever expanding.
Milky
way galaxy is one among the many galaxies.
MILKYwAY GALAXY:
The twinkling
stars
that are seen on a starry
night are actually
like the Sun, but are far away. Many of
these stars are hundreds and thousand times bigger than our Sun. They are seen only as
a small spot of light
because they are very, very far away. Scientists
have found that
planets
revolve
around these stars.
Millions
of stars,
including
the Sun and other
celestial
bodies which can be viewed with our eyes belongs to the Milky way galaxy.
A
white streak of light
can be seen on a clear night for few days. Our ancestors
called
this
as the Milky way galaxy.
In India
it is named as Akash Ganga.
Milky way
galaxy is a dense cluster
of stars.
They appear as a tiny
dot of light
because they are
far away. we live
in the Earth which is part of the solar system in the Milky way
galaxy.
EARTH IS A LIVING PLANET: Earth is the third
planet from the Sun. Mercury and Venus are
very hot planets.
Mars, Jupiter,
Saturn,
Uranus and Neptune are very cold because they
are far away from the Sun. Land, water,
air and heat are available
in the optimum
amount only on Earth.
Therefore
different
kinds of life
develop and increase
only on
Earth.

In our Solar system there is life
only on Earth.
There is no life
on
Earth is called
as Living
Planet
because life
is found in abundance
The period between the full
moon and new moon is called
as waning of
period between the new moon and full
moon is called
as the waxing of

other planets.
only on Earth.
the moon. The
the moon.

ECONOMICS

The basic needs of man are food, clothing
and shelter.
The food we eat like
rice,
wheat, etc. are cultivated
in the land. The farmers
cultivate
food grains.
This is
termed as agriculture.
Agriculture
is the first
known occupation
to man. Man who lived
in caves, to protect
himself
from rain,
cold and heat later
started
to live
in houses.
Cities
began to emerge and man's
need started
to increase.
To fulfill
his needs, he
started
to manufacture
garments,
footwear,
bi-cycles,
cars,
radios and television
sets.
In our daily
life
we utilize
many things.
These things
are sold in shops. To buy and
sell
commodities
we use money. If we save money it is good for us and the country.
Food
helps us to grow. Education
is necessary to grow intellectually.
Medical facilities
protect
us from diseases.
Teachers impart education
and doctors
treat
patients.
Along
with them Government employees work for the welfare
of the people.
Agriculturists,
labourers
and employees help to improve the economy of the country.
This is called
as National
income. what an individual
earns is termed as Per Capita
Income.
Many people do not get income.The Government helps to these people.
Through
this they receive
their
basic requirements.
This is called
distribution.
1 . Production
2. Consumption
3. Distribution
are the basic divisions
in
economics.

A market is a place where things
are bought and sold.
when people purchase commodities
from the market to satisfy
their
requirements,
it is called
consumption.
The buying and
selling
of commodities
is termed as trade.
People who buy and sell things
are called
traders.
Finished
products
are bought by traders
and sold in the markets.
People who
buy and sell
large quantities
of commodities
are called
wholesale
merchants.
People who
buy and sell
small quantities
are called
retailers.
when there is surplus
of
commodities
there is a fall
in price.
when there is deficit
of commodities
there is a
rise in price.

Amarthya Sen Scholar

in Economics (Nobel Laureate)??

The Government supplies
essential
fair
price shops. The Government

commodities
like
has taken several

rice,
steps

dhal,
sugar and oil through
to control
price
rise through

the enforcement
of laws. when there is a shortage
of commodities
the Government imports
them from other countries
and distributes
it through fair
price shops.
As the demand increases
there is an increase
in the production,
consumption
and
distribution.
This is termed as Economic Development.
whatshould
be produced? How does production
take place? These are monitored
by the
Government.
The Government helps in the stable
development
of the country'seconomy.
Those who study Economics become scholars.
To prepare the Central
and State Government
annual budget , it is
necessary to have a knowledge of Economics. A sound knowledge of Economics will
surely
help in the developmental
work in all fields.
In our country
Amarthya Sen received
the
Nobel

Prize

for

Economics.

HISTORY

5. PREHISTORIC PERIOD: An animal called
Dinosaur lived
many million
of the Dinosaur were excavated
near Ariyalur.
They belonged to the
History
tells
about the people who lived
in the past with evidences

years ago. The eggs
prehistoric
period.
according
to the

ages.

The archaeological
excavation
has been going on for 166 years in Athichanallur,
which
is in Tirunelveli
District
in Tamil Nadu.Recently
in 2664,they
excavated more than 166
burial
urns in one place.
This proved that people lived
in that place long ago.
The written
and archaeological
evidences
that tell
us about the period
in which people
lived,
events,
food habits,
customs, culture,
forms of government and literature
are
known as historical
evidences.
History
can be divided
into pre-history
and historical
period.
Historical
period has proof of written
evidences
and other evidences.
The
written
evidences
are literary
work, historical
notes,
stone edicts,
copper plates
and
palm leaves.
Evidences to know about pre-historic
period:
To know about the pre-historic
period,
there are evidences
such as the things
that belonged to that period,
ruins,fossils,horns
and bones of animals,
tools
made of

stones,

skulls

and deposits

(impressions)

the world as well as in India.
with the
historic
period of India.
The Pre-historic

which are found in different

o PalaeolithicAge
- Old StoneAge (BC 16666 years ago)
Age(BC 19999 - BC 4999)
ChalcolithicAge-CopperStone
Age (BC 3666-BC 1566)
IronAge - ironAge (BC 1566 BC 666)
with the help of the tools
used by early
stone age and New stone age.

1. Old StoneAge: ( PalaeolithicAge)

places around

help of all these we know about
period can be classified
as:

Neolithic

man, we can divide

He was a nomad. He lived

the

the

pre-

Age- New Stone

stone

age into

in the jungle.

Old

He took

shelter
on the branches of trees,
in holes and caves. He discovered
fire
by using the
flint
stone. The primitive
man was scared of thunder
and lightning
and worshipped
them.
He had to protect
himself
from cold,
Sun and rain.
He wore dresses made out of leaves,
skin of animals and barks of trees.
He used stones,
branches of trees,
bones and horns
of the animals as weapons. He ate vegetables,
fruits,
roots and meat of animals which
he gathered
from the jungle.
Since he could not find food in one place he went from
place to place in search of food.
Era of some important
events:
Beginning
of the Earth - 4.6 Billion
years ago;

Appearance of man - 4666 years ago (Homosepians);
years ago; Beginning
BC - Before Christ;
Before Common Era;
AT - After

of

Beginning

of agriculture-8666

the cities
-4766 years ago
AD - Anno Domini;
CE - Common Era;
BC 31 - Birth
of Thiruvalluvar;
BT - Before

BCE Thiruvalluvar;

Thiruvalluvar

when he did not find vegetables,
fruits
and roots,
he hunted animals.
He used stones,
branches,
bones, horns of animals etc. to hunt animals.
In the beginning
he hunted
small animals all alone.
Then they hunted in groups.
Both men and women involved
in
hunting.
In the Pimpet Ca cave in Madhya Pradesh we see a painting.
This depicts
a
woman with her child
tied to her waist throwing
an arrow.
From this we know that women
were also involved
in hunting.
Places in India where the Old stone age tools
were found:
Madyapradesh - Soan River bank, Pimpet Ca, Mageshwa.
Rajasthan
- Luni Valley;
Karnataka
- Pagalkhat.
Andhrapradesh
- Karnool caves, Renigunta.

Tamilnadu

- Vadamadurai,

Athirambakkam,

2. New StoneAge: (Neolithic

Pallavaram,

Kanchipuram,

Vellur,

Thiruvallur.

Age) Old stone age man went from place to place in search

of food and for hunting
animals.
Then he learnt
to produce his
animals like goat, cow and hen.
The first
animal he tamed was dog, which helped him in hunting.
cows and had milk as his food. The next stage in the evolution

Food.

He domesticated

He reared goats and
of man is known as New

StoneAge.
During this
age, he used polished,
carved,
sharp stone weapons. In this
period,
he
started
to produce food. wheel was invented.
As a result
of this,
he was able to
transport
things
from one place to another easily.
with the help of wheels he made
pots. He sharpened the crude weapons and attached
them with handles made up of wood and
bones. Metal was in use. Copper was the first
metal used by him. They built
mud houses
with thatched
roofs and began to live
in the pots they used. The Harappan culture
belonged to this
age. - The houses were round or oval shaped. They were built
below the
ground level
and thatched
with wooden planks.
oAgriculture
was their
main
occupation.
Chalcothic
Age weapons. They domesticated
and reared
animals.
4_IronAge:
° Axes,
Fishing

handles made out of bones,
hooks, needle and chopper were in

use.

6 During the New stone age they had the practice
of burying
the dead. The dead were
buried along with their
tamed animals in the front
yard of their
houses. Places where
New stone age weapons were found: Tirunelveli,
Thandikkudi,
Pudukottai,
Tiruchirapalli
and

Salem.

3. CopperAge : (Chalaolithic

Age) At the end of the New stone age, The period when the

tools
were made up of iron was called
Iron Age. Household articles
and agricultural
implements
were made out of iron.
They learnt
to melt the metal and make weapons. They
were creative.
Vedic period belonged to the Iron age.
Madhyapradesh - Pimpet Ca cave
Alloys:
Stainless
Iron + Chromium = Steel;
Copper + Lead = Bronze;
Copper
+ Zinc
Brass;
Iron + Maganese = Steel