NAVODAYA VIDYALAYA SAMITI, NOIDA
E- CONTENT
CLASS- VI
SUBJECT- SCIENCE
CHAPTER NUMBER- 15
NAME OF CHAPTER- AIR AROUND US
PREPARED BY
L.DEEPAK SINGH, TGT SCIENCE
JNV WEST KHASI HILLS, MEGHALAYA
AIR AROUND US�
AT THE END OF THE CHAPTER, YOU WILL BE ABLE TO
YOU HAVE LEARNT THAT ALL LIVING THINGS NEED AIR.
BUT CAN WE SEE AIR?
NO, WE CANNOT SEE AIR
HOW DO WE KNOW THAT AIR IS PRESENT ALL AROUND US?
WE CAN FELT IT PRESENCE IN SO MANY WAYS SUCH AS
RUSTLING OF LEAVES OF TREE
THE CLOTHES HANGING ON THE CLOTHES-LINE SWAY
FLUTTERING OF PAGES OF BOOKS
WINNOWING
AND MANY MORE.
WIND
YOU MIGHT HAVE SEEN TREES BEND WHEN WIND BLOWS.
WHAT IS WIND ?
MOVING AIR IS CALLED WIND.
AIR IS PRESENT ALL AROUND US
ACTIVITY 1.
1.DIP THE OPEN MOUTH OF THE BOTTLE INTO THE BUCKET OR TOUGH FILLED WITH WATER.
2.NOW TILT THE BOTTLE SLIGHTLY.
3. AND OBSERVE WHAT HAPPEN.
Q.CAN YOU SEE BUBBLES COMING OUT OF THE BOTTLE.
Yes
Q. CAN YOU GUESS WHAT WAS IN THE BOTTLE.
‘AIR’
WHAT WE HAVE LEARNT ?
AIR OCCUPIES SPACE.
AIR IS PRESENT ALL AROUND US
AIR HAS NO COLOUR.
AIR IS TRANSPARENT.
ATMOSPHERE
Our earth is surrounded by a thin layer which extents up to many kilometres above the surface of the earth called atmosphere.
ATMOSPHERE
Q why do mountaineers carry oxygen cylinder with them
when they climb high mountains ?
As we move higher in the atmosphere, the air gets thinner and
thinner that is why there is less air in higher mountains that’s
why the mountaineers carry oxygen cylinder when they climb
high mountains.
WHAT IS AIR MADE UP OF ?
Untill eighteen century, people thought that air was just one
substance.
So , what is air actually made up of ?
Air is made up of many gases.
They are
- Dust and smoke
WATER VAPOUR
Q. From where the water droplets on the outer surface of the glass tumbler comes from?
When the water vapour present in air comes in contact with the cooled outer surface of the glass tumbler the water vapour condenses and drops of water appear on the outer surface of glass tumbler. Therefore water vapour is present in air.
WATER DROPLETS
OXYGEN
Activity-2
inverted glass tumbler or bell jar.
4. Observe both the candle carefully.
Q why the candle covered with glass tumbler or bell jar got extinguished ?
which supports burning inside the tumbler or bell jar is limited
that’s why it got extinguished ..
Q what is the name of that component of air ?
- oxygen
Why during an incident of fire, one is advised to wrap
a woollen blanket on a burning object ?
The woollen blanket cuts off the supply of air
(oxygen) which help in burning of the object. When
the supply of oxygen is cut out the objects stops
burning.
NITROGEN
CARBON DIOXIDE
US.
PRODUCE CARBON DIOXIDE.
AND PRODUCES MAINLY CARBON DIOXIDE AND FEW OTHER GASES.
DUST AND SMOKE
Q why we see long chimneys in factories ?
The long chimneys in factories
take away the harmful smoke from our noses.
DUST AND SMOKE
Activity-3
2. Close all the doors and windows with curtains
pulled down to make the room dark
Sun, just a little to allow sunlight to enter the room
only through a slit.
4. Look carefully at the incoming beam of sunlight.
Q what do you see in the beam of sunlight ?
Q what are these tiny shinny particles ?
Q what you have learnt from this activity ?
-Air also contain dust particles.
Q Why do you think, the policeman is wearing a mask ?
always exposed to dust and smoke of the vehicles
which is harmful to the heath therefore in order to
protect from dust and smoke the policeman is wearing a
mask.
Q Why we should breath through our nose?
We should breath through our nose because fine hair and mucus are present inside the nose to prevent dust particles from getting into the respiratory system.
Q why the transparent glass of windows, if not wiped off
regularly, appear hazy ?
-Air contain some gases, water vapour and dust particles that
stick to transparent glass of window that is why the
transparent glass of windows, if not wiped out regularly, appear hazy.
COMPOSITION OF AIR
-The gases in air are mainly nitrogen,
oxygen, small amount of carbon dioxide, and many other gases.
How does oxygen become available to animals and plants living in water ?
Activity 4
container.
2.Heat it slowly.
3.Well before the water begins to boil, look
carefully at the inner surface of the container.
Q. Can you see tiny bubbles at the inner surface of the container ?
Q From where these tiny bubbles come from ?
Q What you have learnt from this activity ?
Air (oxygen) is present in water and the animals living in water
used thedissolved oxygen in water.
How does oxygen become available to animals and plants living in water ?
Activity 5
Q How the bubbles were formed ?
When the water is poured on the lump of soil, it displaces
the air which is present in the soil and the air comes out
in the form of bubbles.
ANIMALS THAT LIVE IN SOIL
- There are some organisms that live in the soil.
-A lot of burrows and holes are formed in deep soil by animals living in the soil.
-The burrows also make spaces available for air to move in and out of the soil and in this way some of the animals can breath inside the soil and live.
BURROW
INTERDEPENDENT OF PLANTS AND ANIMALS
releases carbon dioxide.
-In this way the balance of oxygen and carbon dioxide in the
atmosphere is maintained through respiration in plants and
animals and by photosynthesis in plants.
WINDMILL
-Windmill is used to draw water from tube wells and
to run flour mill.
- Windmill is also used to generate electricity.
USES OF AIR
WHAT YOU HAVE LEARNT
1. Air is found everywhere. We cannot see air but we can feel it
vapour , and a few other gases. Some dust particles may also be
present in it.
respiration.
8.Plants and animals depend on each other for exchange of
oxygen and carbon dioxide from air.
SOME USEFUL WEBSITE LINKS