chapter 15 air
Post on 22-Feb-2016
35 Views
Preview:
DESCRIPTION
TRANSCRIPT
CHAPTER 15 AIRCLASS VI
AIR IS PRESENT EVERY WHERE AROUND US.
• MOVING AIR IS CALLED WIND.
• ACTIVITY:• An empty bottle is inverted and dipped under
water. • Water does not enter inside bottle because the
space inside the bottle is filled with air.• On tilting, air goes out of the bottle.Now water
enters the bottle. • AIR OCCUPIES SPACE
PROPERTIES OF AIR• AIR HAS NO COLOUR. IT IS TRANSPARENT.• THE ENVELOPE OF AIR AROUND EARTH IS
CALLED ATMOSPHERE.
ATMOSPHERE
• As we go higher and higher, above the suface of earth, the thickness of air becomes less .
• At the top of high mountains, oxygen is less.
• Mountaineers carry oxygen cylinders with them.
• AIR IS A MIXTURE OF GASES.
COMPOSITION OF AIR - * NITROGEN -78% * OXYGEN -21% * CARBONDIOXIDE - 0.04% * WATER VAPOUR * DUST &SMOKE
OTHER S
WATER VAPOURWATER VAPOUR IN AIR IS AN IMPORTANT PART
OF WATER CYCLE
OXYGEN
• HELPS IN BURNING • ESSENTIAL FOR BREATHING
• ACTIVITY:• TAKE WATER IN A CONTAINER
AND HEAT IT.
WE OBSERVE TINY BUBBLES ON THE SURFACE OF VESSEL , AFTER SOME TIME.
THESE BUBBLES COME FROM AIR DISSOLVED IN WATER.
• OXYGEN DISSOLVED IN WATER IS USED BY AQUATIC ORGANISMS
• OXYGEN PRESENT IN AIR IN BETWEEN SOIL PARTICLES IS USED BY SOIL ORGANISMS.
• EARTHWORMS COME OUT OF THEIR BURROWS DURING RAIN .
WATER occupis all spce in between the soil particles ,replacing air.Eatrh worms find it difficult to breath.
AIR IS ESSENTIAL FOR BURNINGACTIVITY:
NITROGEN
• NITROGEN DOES NOT SUPPORT BURNING.• IT IS AN IMPORTANT PLANT NUTRIENT.
CARBONDIOXIDE
• RELEASED IN THE ATMOSPHERE DURING RESPIRATION ,BURNING, DECOMPOSITION etc.
CARBONDIOXIDE• USED BY PLANTS FOR PHOTOSYNTHESIS.
CARBONDIOXIDE• IT CAN EXTINGUISH FIRE.
DUST
• DUST PARTICLES ARE PRESENT IN AIR.
• Hairs present in nasal cavity prevent the dust particles from entering into the respiratory system.
SMOKE
• RELEASED BY VEHICLES, FACTORIES, KITCHEN BURNING OF OTHER MATERIALS.• CONTAIN HARMFUL GASES LIKE , OXIDES OF
NITROGEN, SULPHUR, CARBON etc.
• LONG CHIMNEYS OF FACTORIES TAKES THIS SMOKE AWAY FROM US BUT BRING IT CLOSER TO THE BIRDS.
OXYGEN CYCLE
PHOTOSYNTHESISRESPIRATION
[OXYGEN][CARBONDIOXIDE]
USES of AIR
FILL IN THE BLANKS• 1.AIR IS A ----------------------OF GASES.• 2.THE ENVELOPE OF AIR AROUND EARTH IS--------------.• 3.THE MAJOR CONTENT OF AIR IS -----------------GAS.• 4. --------------------GAS IS ESSENTIAL FOR BURNING.• 5. THE GAS USED FOR PHOTOSYNTHESIS IS -----------------.• 6.EARTH WORM BREATH AIR PRESENT IN ------------• 7.FISHES BREATH OXYGEN PRESENT IN --------------.• 8.---------------------------GAS CAN EXTINGUISH FIRE.
MIXTURE ATMOSPHERE
NITROGENOXYGEN
CARBONDIOXIDE
SOIL
WATERCARBONDIOXIDE
SAY TRUE OR FALSE• 1.MOVING AIR IS CALLED WIND.• 2.AIR DOES NOT NEED SPCE TO OCCUPY.• 3.CARBONDIOXIDE SUPPORTS BURNING . 4. EARTHWORMS BREATHE AIR PRESENT IN SOIL.
• 5. PLANTS AND ANIMALS DEPEND ON EACH
OTHER FOR EXCHANGE OF OXYGEN AND CARBONDIOXIDE FROM AIR.
6.HAIRS INSIDE THE NASALCAVITY FILTER CARBONDIOXIDE PRESENT IN AIR.
TRUEFALSE
FALSE
FALSE
TRUE
TRUE
top related