What is the only substance that is found in all three states in the atmosphere?

Answer 1

Water exists in all three states (gas, liquid, solid) in our atmosphere.

The gaseous state is pretty well recognized just as the humidity in the air.

Water, as individual H2O molecules, is dissolved in the air and so one of the component gasses of air along with oxygen, nitrogen and others. There are typically a few grams of water per cubic meter of air all over the world.

Liquid water is also known in several forms in the air. When one sees a mist, one is seeing tiny droplets of liquid water. Fog is the same. Steam is the same. Obviously, rain is an example of liquid water even the though we don't think of it as being there for very long. In fact, some of the lower clouds we see in the sky contain liquid water drops that are so small they are not falling as rain.

But, the subject of clouds brings us to the solid state of water in the air. As we know, snow is solid water and certainly comes to us through the atmosphere. Many people think that snow is water that has frozen on its trip down from the clouds. While that is possible, what is most common is that the clouds we see high in the atmosphere contain ice crystals. Temperature drops pretty rapidly as we go up in altitude and it does not take much height before water vapor condenses out and then turns into tiny ice crystals that appears to us as clouds.

The ice and liquid water in clouds is described nicely on Wikipedia.