7 Class.Geography.CW/HW.Chapter4.Air Around Us.

7 Class.Geography.CW/HW.

Chapter4.Air Around Us.
  

Keywords 

Global Warming : a gradual increase in the overall temperature of the earth's atmosphere.  

Immunity : amount of water vapors in the atmosphere

monsoons : seasonal reversal of the wind direction according to the change in the season 

photosynthesis : plants observes Co2 in the presence of sunlight and turn that  energy into food 
Something to Know 

Tick  the correct options 

1.in the normal lapse rate  temperature decreases at the rate of 1 degree with every 

(a) 165  m ascend 

(b) 175 m  ascend 

(c) 185 m ascend

(d) 195 m ascend  

2. Which layer is safe for flying air crafts 

(a) troposphere 

(b) stratosphere 

(c) mesosphere 

(d) thermosphere

3. The role of nonparticles in the atmosphere is to  

(e) absorb ultraviolet rays 

(b) enable wireless communication 

(c) burn metors 

(d) enable rainfall 

4. Which one of the following in the main cause of global warming? 

(a) air pollution 

(b) water pollution 

(c) sol pollution 

(d) land  degradation 

5. Smog causes 

(a) breathing problems 

(b) purification of air 

(c) heavy rainfall 

(d) reduction in temperature 

B. fill in the blanks 

1. Atmosphere is mainly composed of three major gases nitrogen.----------- and 

2. Gases like argon,  bellum, methane, et, are present in ----------amounts in the air 

3. All weather phenomena occur in the ----------

4. Amospheric conditions over a long period of time and on a larger area is called 

5. The normal air pressure to level is ------
 
C.  Match the following : 

1. Mono oxide gas a.  Weight or pressure exerted by the air 

2. Weather b.  Most harmful gas present in the atmosphere.

3. Barometer  c. The falling of water drops on the earth's surface.

4. Atmospheric Pressure    d.  An instrument to measure atmospheric pressure.

5. Rainfall e.  Atmospheric conditions for a specific place covering a short period of time, 

D. Answer the following questions in brief.  

1. Name the layers of the atmosphere. 

2. How do plants absorb nitrogen?  

3. What is the importance of water vapors in the atmosphere?  

2 .Name the different variables of atmosphere.  

5. What type of climate does India have?  

E. Answer the following questions.  

1. What is the importance of carbon dioxide and oxygen for living beings?  

2. Name three major sources of pollutants in the air.  Also state the ill - effects of these air pollutants.  

3. What is the importance of ozone gas?  Why is global warming a threat to life on the earth?  

4. How is rainfall caused?  Explain it with the help of a diagram.  

5. Write the difference between weather and climate.  

Value Based Question 

Global warming is threatening the life support system of the earth. 

How can we relate our life with it? Give examples in support of your answer. 

Explain any two measures to combat this problem.
Something To Do 1. Collect the weather report of the last week from the newspapers and write it in the following tabular form.  

Day Monday Tuesday Wednesday Thursday Friday Saturday Sunday 

Date 

Weather Report 

2. Make a PowerPoint presentation on the following topics and present it in the class.  

(a) Global warming (b) Air pollution 32
Chapter 6