6th Standard Science ( Air Around Us )

   Class 6 Science Air Around Us

 

I. Fill in the blanks:

1.The layer of air around the earth is known as Atmosphere

2.The component of air used by green plant to make their food is Carbon dioxide. 

 

II. Answer the following:

1.What is the composition of air?
Ans:Air contains some gases mainly nitrogen, oxygen, small amount of carbon dioxide, water vapour and dust particles

 

2.Which gas in the atmosphere is essential for respiration?
Ans:Oxygen gas is essential for respiration.

 

3. How will you prove that air support burning?
Ans: Step 1: Two shallow containers are taken and burning candles are fitted into it.
step 2: Now, water is filled in the container at two different levels.
Step 3: Both the candles are then covered with glass.
Step 4: After sometime, we observe that the candles having less water in its container stops burning.
This happened because the container having more water contains more oxygen and therefore it bums for more time, Thus, it is proved that air support burning.

 

4. How will you show that air is dissolved in water?
Ans: Steps 1: Water is taken in a pan.
Steps 2: It is now boiled on a stove
Steps 3: We will observe tiny visible bubbles of water visible, coming out from the bottom of the pan. These tiny bubbles are coming due to the air dissolved in water Thus this proves that air is dissolved in water.

 

5. Why does a lump of cotton wool shrink in water?
Ans:The lump of cotton contains air in it, when it comes in contact with water, the air is pushed out from the vacant space and dissolved in water and thus a lump of cotton wool, shrinks in water.

6. List five activities that are possible due to the presence of air
Ans: a) Helps in seed dispersal and pollination
b) Sailing of ships
c) Flying of the birds and kites
d) Gives us oxygen to respire
e) Moving air helps in the rotation of wind mill

7. How do plants and animals help each other in the exchange of gases in the atmosphere?
Ans:Plants take in CO₂ in during photosynthesis and give out oxygen into the atmosphere, while animals take in oxygen and breathe out carbon dioxide during respiration, In this way, plants and animals help each other in the exchange of gases in the atmosphere.