Question

Suggest three reasons why you think air is a mixture and water is a compound

Answer 1

Air is a mixture because:
1) Its components vary from place to place
2) Its components continue to vary
3) Its components can be seperated by physical means

Water is a compound because:
1) Its components are bound together chemically
2) Its components always occur in a fixed proportion -- be it tap water, sea water, etc.
3) Its components cannot be seperated by physical means