Identifying Chemical vs Physical Changes

[Maroc]

Homework Statement

How would you know wheather its a chemical change or physical change

Homework Equations

The Attempt at a Solution

 

[Borek]

What does your book say about?

 

[Maroc]

just says something about the physical apperance as for chemical a change in the gas happens...i don't get it

 

[Borek]

http://www.google.com/search?num=25&hl=en&q=difference+between+chemical+and+physical+change