Air is a mixture and water is a compound due to following reasons. 1) Air is formed by simple or physical mixing of different gases while water is formed by chemical combination of hydrogen and oxygen. 2) air does not have any chemical formula while water has chemical formula that is H2O.
- Components of air can be separated by ordinary physical means while water can not be separated into its components by ordinary physical methods.
- There is no fixed ratio of gases in air while in water hydrogen and oxygen has a fixed ratio by mass.