RBSE Solutions for Class 7 Social Science Geography Chapter 4 Air

Rajasthan Board RBSE Solutions for Class 7 Social Science Geography Chapter 4 Air Textbook Exercise Questions and Answers.

RBSE Class 7 Social Science Solutions Geography Chapter4 Air

RBSE Class 7 Social Science Air InText Questions and Answers

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Question 1. 
Do you know that the air we take in while breathing is actually a mixture of many gases?
Answer:
Air protects us from harmful rays of the sun and consists of nitrogen 78%, oxygen 21%, 0.03% carbon dioxide, helium,
0. 93% argon and water vapours. Nitrogen is essential for plants. Oxygen is essential for humans and animals.

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Question 2. 
For 10 days note down weather report from a local newspaper and observe the changes occurring in the weather?
Answer:
The students need to do the activity on their own.
Hint: 
Students can take help of newspaper or news channels to note the daily weather condition in a tabular format and later observe the changes.

RBSE Class 7 Social Science Air Textbook Questions and Answers  

Question 1. 
Answer the following questions
(i) What is atmosphere?
Answer:
Our earth is surrounded by a huge blanket of air called atmosphere. So, this mass of air has made the temperature on the earth livable.

(ii) Which two gases make the bulk of the atmosphere?
Answer:
Nitrogen (78%) and oxygen (21%) are the two main gases of the atmosphere.

(iii) Which gas creates green house effect in the atmosphere?
Answer:
Carbon dioxide creates green house effect in the atmosphere.

(iv) What is weather?
Answer:
Weather is hour to hour and day to day condition of the atmosphere.

(v) Name three types of rainfall? 
Answer:
Three types of rainfall are:
(a) Convectional rainfall,
(b) Orographic rainfall,
(c) Cyclonic rainfall.

(vi) What is air pressure?
Answer:
The pressure exerted by the weight of air on the earth’s surface is called air pressure.

Question 2. 
Tick the correct answer :
(i) Which of the following gases protects us from harmful sun rays?
(a) Carbon dioxide 
(b) Nitrogen 
(c) Ozone
Answer:
(c) Ozone

(ii) The most important layers of the atmosphere is
(a) Troposphere 
(b) Thermosphere
(c) Mesosphere
Answer:
(a) Troposphere 

(iii) Which of the following layers of the atmosphere is free from clouds?
(a) Troposphere 
(b) Stratosphere
(c) Thermosphere
Answer:
(b) Stratosphere

(iv) As we go up the layers of the atmosphere, the pressure:
(a) Increases 
(b) Decreases
(c) Remains the same
Answer:
(b) Decreases

(v) When Precipitation coines down to the Earth in the liquid form, it is called:
(a) Cloud 
(b)Rain
(c) Snow.
Answer:
(b)Rain

Question 3. 
Match the following

Answer:

Question 4. 
Give Reasons
(i) Wet clothes take longer time to dry on a humid day.
Answer:
When water evaporates from land 
and different water bodies, it becomes water vapour. Moisture in the air at any time, is known as humidity. When the air is full of water vapour we call it a humid day. As the air gets warmer, its capacity to hold the water vapour increases, and so it becomes more arid more humid and that is why wet clothes take longer time to dry on a humid day.

(ii) Amount of insolation decreases from equator towards poles.
Answer:
Insolation is heat of the sun received by the earth. Sun’s rays fall vertically on 0° equator so it receives more solar radiation thus more insolation. Towards poles the sun rays are slanting so they receive less amount of insolation