Question

This layer of the Earth's atmosphere contains the fewest molecules of the layers shown, and the low density of gas leads to very few molecules transferring heat to an object. In this layer, ultraviolet radiation causes photodissociation of molecules, creating ions.

a) troposphere
b) stratosphere c) mesosphere
d) thermosphere

Answer 1

The correct answer is (c) mesosphere.

The mesosphere is the layer of the Earth's atmosphere that contains the fewest molecules compared to the other layers. Due to its low density of gas, there are very few molecules transferring heat to an object in this layer.

In the mesosphere, ultraviolet radiation from the sun causes photodissociation of molecules. Photodissociation is the process where molecules are broken apart into ions or smaller particles due to the energy from UV radiation. This leads to the creation of ions in the mesosphere.

To summarize, the mesosphere is the layer of the Earth's atmosphere with the fewest molecules, and its low density of gas results in minimal heat transfer. Ultraviolet radiation in this layer causes photodissociation of molecules, creating ions.