Question

what is difference between gas and air

Answer 1

Gas' is a one of the many states of matter. The other common/ non-exotic states of matter are 'solid', 'liquid' and 'plasma'. 'Air' as in the atmosphere we live in and breathe, on the Earth, is a mixture of various gases such as nitrogen, oxygen, carbon dioxide, and so on. Thus, air is gaseous.

Answer 2

Gas is the particular substance that in the form of gas.

but .....

Air is the mixture of so many substances