Question

The fifth layer of Earth’s atmosphere is____.
A)Exosphere
B)Mesosphere
C)Thermosphere
D)Troposphere

Answer 1

Hint: The blanket of air that surrounds our earth is called atmosphere. The earth’s atmosphere is composed of gases like nitrogen, oxygen ,argon, carbon dioxide, water vapour etc.

Complete answer: The earth’s atmosphere stretches from the surface of the planet to 10000km above the planet. Based on temperature, Earth’s atmosphere is divided into five layers. The layers are called troposphere, stratosphere,mesosphere, thermosphere and exosphere.
Let us look at the options given to us-
Option A- Exosphere is the fifth layer of atmosphere. It is the layer that fades into space. It is an extremely thin layer and has gases like hydrogen and helium. The exosphere starts at about 500km above earth’s surface and goes upto 10000km.
Option B-Mesosphere is the third layer of atmosphere and reaches about 85km above earth. The temperature here decreases with altitude and the atmosphere is thin but thick enough to burn up the meteors as they pass through it.
Option C-Thermosphere is the fourth layer of atmosphere and here temperature increases with altitude .
Option D- Troposphere is the first layer in the atmosphere and reaches till about 15km from earth’s surface. Temperature here decreases with altitude and this is the layer which has clouds and water vapour.

Therefore, The correct answer is option (A).

Note: The Stratosphere is the second layer in the atmosphere and it extends to 50km above earth’s surface. It is the layer in which the ozone layer is present. Commercial airplanes fly in the lower stratosphere.