CHAPTER 15 AIR CLASS 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 VAPOUR WATER 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 PRESENT IN AIR IN BETWEEN SOIL PARTICLES IS USED BY SOIL ORGANISMS. OXYGEN DISSOLVED IN WATER IS USED BY AQUATIC 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 BURNING ACTIVITY:

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 PHOTOSYNTHESIS RESPIRATION [CARBONDIOXIDE] [OXYGEN]

USES of AIR

FILL IN THE BLANKS MIXTURE ATMOSPHERE NITROGEN 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. ATMOSPHERE NITROGEN OXYGEN CARBONDIOXIDE SOIL WATER CARBONDIOXIDE

SAY TRUE OR FALSE TRUE 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. TRUE FALSE FALSE TRUE TRUE FALSE