Question

If there were no atmosphere around the earth, the temperature of the earth will ________
A. Increasing
B. go on decreasing
C. increase during day and decrease during night
D. be unaffected

Answer 1

Hint: Due to absence of atmosphere in the moon, it has a temperature range from $ - {190^ \circ }C$ to ${110^ \circ }C$. So, there is no possibility of life on the moon.

Complete answer:
To solve this question we need to know about the atmosphere that surrounds the earth.
The earth is surrounded by a layer of a gas called atmosphere. The atmosphere contains different layers, with variable density and temperature. Density is highest when it is near the surface of the earth and it decreases with increasing altitude.
Atmosphere is divided into five concentric layers of air or regions, depending upon the temperature conditions. These layers are:
1. Troposphere – It is the lowest region of atmosphere in which the human beings along with their organisms lives are called the troposphere. It extended up to the height of 8 to 18 km from sea level. It contains more than 90% of gas.
Troposphere contains dust particles, water vapor, storms, clouds and rain, all changes in climate take place in this layer. In this layer temperature decreases with height. It is the most important layer for all biological activities.
2. Stratosphere - It extends 50km above the sea level and lies in the stratosphere. It contains dinitrogen, dioxygen, ozone and little water vapor. At the height of 15-30 km, a thin layer of ozone is present in the stratosphere.
3. Mesosphere - It extended up to an altitude of 50 -85km that shows a decrease of temperature with the height. Minimum temperature of it is 92°C.
4. Ionosphere - It extends up to 85-500 km. In this region gases are ionized due to high temperature (up to 1200°C). The Ionosphere protects from the cosmic rays and site of wireless communication.
5. Exosphere - It is outer space.
As per the above description of atmosphere and its layer, we can easily understand that the atmosphere has an average temperature for day and night. If there were no atmosphere around the earth, the temperature would get affected. In the absence of atmosphere, there would be no life, no rains, no winds, no fires and also no ozone layer that would be used as a protection layer against harmful radiations. The earth was becoming like a moon that had temperatures ranging from $ - {190^ \circ }C$ to ${110^ \circ }C$.

So, the correct answer is option C, increase during day and decrease during night.

Note: If there is no atmosphere in the earth, then there will be no production of sound as the sound waves require a medium. The sky will become black in color, because it is the atmosphere that gives blue color to the sky.