What is Air?

What is Air?

The atmosphere is divided into four layers, the troposphere, stratosphere, mesosphere and thermosphere. [AM] {GC} {WW}
The troposphere contains all things which combine to make our weather.
The stratosphere contains a layer of ozone which absorbs some of the Sun's harmful rays, heating up the layer.
The mesosphere is coldest at the top at -100 degrees celcius, but the bottom warms up because of the warm stratosphere layer beneath.
The thermosphere contains gases which absorb some of the harmful solar radiation, which in turn heats the layer. [VH] {WC}