Briefly answer the following question:
 
Why is the formation of steam during boiling not considered a chemical change?
 
Boiling water is considered a because only the of water changes from liquid to gas. The steam formed is still in gaseous form and no is produced. The chemical composition of water remains the same before and after boiling. This change is also  because steam can cool and become liquid water again. Therefore, boiling water is classified as a physical change.