Tick the correct answer.
Which of the following gases protects us from harmful sun rays?
- Carbon dioxide
- Nitrogen
- Ozone
The most important layer of the atmosphere is
- Troposphere
- Thermosphere
- Mesosphere
Which of the following layers of the atmosphere is free from clouds?
- Troposphere
- Stratosphere
- Mesosphere
As we go up the layers of the atmosphere, the pressure
- Increases
- Decreases
- Remains the same
When precipitation comes down to the earth in the liquid form, it is called
- Cloud
- Rain
- Snow
Match the following
| Trade Winds | Incoming solar energy |
| Loo | Seasonal wind |
| Monsoon | The horizontal movement of Air |
| Wind | Layer of ozone gas |
| Permanent wind | |
| Local wind |
Class 7 Geography Chapter 4 Air Notes
Nitrogen is the most plentiful gas in the air.
Green plants produce oxygen during photosynthesis.
Our atmosphere is divided into five layers starting from the earth’s surface. These are Troposphere, Stratosphere, Mesosphere, Thermosphere, and Exosphere
The degree of hotness and coldness of the air is known as temperature.
An important factor that influences the distribution of temperature is insolation.
The movement of air from a high-pressure areas to low-pressure areas is called wind.
A wind is named after the direction from which it blows, e.g. the wind blowing from the west is called westerly.
Winds can be broadly divided into three types.
Permanent winds – The trade winds, westerlies, and easterlies are the permanent winds.
Seasonal winds – These winds change their direction in different seasons.
Local winds – These blow only during a particular period of the day or year in a small area. For example, land and sea breeze.
Moisture in the air at any time is known as humidity.
Precipitation that comes down to the earth in liquid form is called rain.