Is the sky a solid liquid or gas

Gas.
The sky is not solid, not liquid but of gas. It is also called the atmosphere, one of the important spheres on earth that influences the climate –temperature, humidity, precipitation, atmospheric pressure, and the biotic community as a whole. The atmosphere or the sky is composed of many layers and is responsible to protecting the living organisms of the earth against the deadly ultraviolet rays and other strong radiation coming from the sun.

Any photo? or something