Question

Atmosphere consists of
A. Lithosphere and hydrosphere
B. Lithosphere, stratosphere and hydrosphere
C. Troposphere, stratosphere and ionosphere
D. None of the above

Answer 1

Hint: The earth’s atmosphere is divided based on chemical composition into two broad layers: the heterosphere and the homosphere. Earth’s atmosphere is composed of about 78% nitrogen, 21% oxygen, and 0.93% argon. It is also composed of trace gases of about less than 0.1% such as water vapour, carbon dioxide, and ozone. One of the gases essential for all life forms on earth is oxygen, which is required for the respiration by all animal life forms, from humans to bacteria.

Step by step answer:The earth’s atmosphere consists of all of these gases that have important effects on the earth’s climate. Based on the way temperature changes with altitude, the atmosphere can be divided into vertical layers. The layer closest to the surface is the troposphere, which contains nearly all the water vapour and over 80% of the atmospheric mass. Above the stratosphere are the mesosphere and thermosphere.
-Lithosphere: The lithosphere is the coolest part of the earth. It is the rocky and rigid outer part of the Earth. It comprises of the brittle crust and the top portion of the upper mantle.
-Hydrosphere: A hydrosphere constitutes the total amount of water on a planet. The water present on the surface of the planet, underground, and in the air is the hydrosphere. A planet's hydrosphere can be present either in the form of liquid, vapour, or ice. Earth’s hydrosphere consists of water in liquid form. It exists on the surface in the form of oceans, lakes, and rivers.
-Troposphere: The atmospheric layer closest to the earth’s surface is the troposphere and it is considered as the most-dense part of the atmosphere. This region includes almost all weather. The troposphere extends up to 14.5 kilometers high (9 miles).
-Stratosphere: The stratosphere layer starts just above the troposphere layer and extends to 50 kilometers (31 miles) high. The ozone layer is present in this layer and it absorbs and scatters the solar ultraviolet radiation.
-Mesosphere: The mesosphere is the third highest layer and extends to 85 kilometers (53 miles) high. At the lowest level of the mesosphere, the temperature is warm and it gets colder at higher levels. Meteors burn up in this layer due to friction with the wind.
-Thermosphere: The thermosphere layer starts just above the mesosphere atmospheric layer and extends up to 600 kilometers (372 miles). Satellites are present in this layer.
-Ionosphere: This layer overlaps into the mesosphere and thermosphere atmospheric layers and has an abundance of electrons, ionized atoms, and molecules. This region is significant for radio communications because the radio waves can bounce off the layer and travel great distances.
-Exosphere: This is the uppermost limit of the earth's atmosphere.
Hence.the correct answer is C. Troposphere, stratosphere and ionosphere.

Note: Ozone is vital to life forms on earth because it absorbs most of the high-energy radiation from the sun that is harmful to plants and animals. The sun radiates energy which lies in the ultraviolet region. The shorter wavelength radiation causes potential harm to cells, resulting in skin cancer. At lower altitudes, ozone gas is irritating to the eyes and skin. It chemically attacks rubber and plant tissue.