Question

In which of the following, ionized gases are the main constituents?
A.Troposphere
B.Stratosphere
C.Mesosphere
D.Thermosphere

Answer 1

We know that Earth's atmosphere contains a series of layers, each with its own particular traits. From ground level on moving upward, these layers are named as the troposphere, stratosphere, mesosphere, thermosphere and exosphere. The exosphere gradually fades away into the interplanetary space.

Complete step by step answer:
We can say the troposphere is the lowest layer of our atmosphere. Beginning at ground level, it extends upward to about 10 km above sea level. We humans reside in the troposphere, and all weather changes take place in this lowest layer. Most clouds are found here, because 99% of the water vapor in the atmosphere is seen in the troposphere. Therefore, option (A) is incorrect.
The next layer up after the troposphere is known as the stratosphere. The ozone layer is seen inside the stratosphere. In the lower stratosphere, commercial passenger jets fly, because the stratosphere is a less-turbulent layer that offers a smoother ride. The stratosphere gets warmer as we move higher.
Therefore, Option (B) is incorrect.
Above the stratosphere, is the next layer known as mesosphere. It extends upward to a height of about 85 km above Earth. Several meteors burn up in the mesosphere. As we go up through the mesosphere, the temperature gets colder.
Therefore, Option (C) is incorrect.
The layer of the Earth's atmosphere directly above the mesosphere and directly below the exosphere is known as the thermosphere. Within this layer, ionization is caused by ultraviolet radiation. The thermosphere starts about 85 kilometres above the Earth. At these high altitudes, the residual atmospheric gases sort into strata based on molecular mass. Thermospheric temperatures rise with altitude because of highly energetic solar radiation absorption. The part of the thermosphere between the altitudes of 50 km and 100 km is known as the ionosphere. In this region, high concentrations of ions and electrons are found. Therefore, Option (D) is correct.

So, the correct answer is Option D .

Note:
We must remember that the ionosphere is not a separate layer like the other layers. Ionosphere is a chain of areas in measures of the mesosphere and thermosphere. In ionosphere, high-energy radiation from the Sun has hit electrons loose from their parent atoms and molecules. The electrically charged atoms and molecules produced are called ions. The ionosphere is because of the formation of ions and donating this region with certain unique properties.