how can Ethan BEST describe his conclusion

Question

Ethan is observing chemical and physical properties of a substance he heats a substance and observes that the substance turn from a brown solid to a black powder he refers to several chemistry journals that claim this represents a chemical reaction from his observations and research he concludes that the substance goes through a chemical change when heated how can Ethan best defend his conclusion

Answer 1

What are the properties of matter that are used to define it - what properties might change, and how would they change, if a substance went through a chemical reaction?  Without knowing anything more than that heat is involved in the suspected change, you (or Ethan) has to think of some physical tests on both the brown and black substances that would show whether or not a change has taken place.  

Hopefully, Ethan did more than just watch - I hope he took some notes, and watched the brown solid very closely as he heated it.  

 

From your understanding of chemistry, and what a chemical reaction is, and isn't -- you should be able to come up with a few things he can do to show whether or not the brown substance has undergone a chemical reaction, and how the black substance is different from the brown one.