Air Book Back Questions 6th Science Lesson 11
6th Science Lesson 11
11] Air
Book Back Questions with Answer and Do You Know Box Content
Do You Know?
A weathercock shows the direction in which the air is moving at a particular place. You can also make a wind sock to find the direction of the wind. Can you try it yourself?
When carbon-di-oxide is cooled to -57oC, it directly becomes a solid, without changing to its liquid state. It is called dry ice and is a good refrigerating agent. Dry ice is used in trucks or freight cars for refrigerating perishable items such as meat and fish while transporting them.
Choose the best answers:
1. __________________ is the percentage of nitrogen in air.
(a) 78%
(b) 21%
(c) 0.03%
(d) 1%
2. Gas exchange takes place in plants using _________________
(a) Stomata
(b) Chlorophyll
(c) Leaves
(d) Flowers
3. The constituent of air that supports combustion is ____________
(a) Nitrogen
(b) Carbon-di-oxide
(c) Oxygen
(d) Water vapour
4. Nitrogen is used in the food packaging industry because it _________________
(a) Provides colour to the food
(b) Provides oxygen to the food
(c) Adds proteins and minerals to the food
(d) Keeps the food fresh
5. _______________ and ____________ are the two gases, which when taken together make up about 99 percentage of air.
I. Nitrogen II. Carbon-di-oxide III. Noble gases IV. Oxygen
(a) I and II
(b) I and III
(c) II and IV
(d) I and IV
Fill in the blanks:
1. ____________________ is the active component of air.
2. The gas given out during photosynthesis is ____________
3. _________________ gas is given to the patients having breathing problems.
4. _____________ can be seen moving in a beam of sunlight in a dark room.
5. _____________ gas turns lime water milky.
State true or false. If false, correct the statement:
1. Inhaled air contains a large amount of carbon-di-oxide.
2. Planting trees help in decreasing global warming.
3. The composition of air is always exactly the same.
4. Whales come up to the water surface to breathe in oxygen.
5. The balance of oxygen in atmosphere is maintained through photosynthesis in animals and respiration in plants.
Match the following:
1. Moving Air – Photosynthesis
2. Layer in which we live – Troposphere
3. Stratosphere – Wind
4. Oxygen – Ozone layer
5. Carbon-di-oxide – Combustion
Complete the analogy:
1. Photosynthesis: _______________ :: Respiration: Oxygen
2. 78% of air: Does not support combustion :: _______________ : supports combustion
Answers:
Choose the correct answer:
1. 78% 2. Stomata 3. Oxygen 4. Keeps the food fresh 5. Nitrogen and Oxygen
Fill in the blanks:
1. Oxygen 2. Oxygen 3. Oxygen 4. Dust particles 5. Carbon-dioxide
Say True or False:
1. False
Correct Statement: Inhaled air contains large amount of oxygen.
2. True
3. False
Correct Statement: The composition of air varies from place to place.
4. True
5. False
Correct Statement: The balance of oxygen in atmosphere is maintained through photosynthesis in plants and respiration in animals.
Match the following:
1. Wind 2. Troposphere 3. Ozone layer 4. Combustion 5. Photosynthesis
Complete the analogy:
1.Carbon-dioxide 2. 21% of air