When making a guess and Retesting This information, a model or may be formed which explains why something has occurred or what it may look like.

Aphysical change is one that you can put in and remove like a ham sandwich. the stuff you put in there can be changem its not permanet. a chemical change is on that can't be change thats permanet. like when you make a cake and bake it. you can't get those ingredients back.

Carbon based or cells?