Explain the convection cycle that takes place within Earth's layers. Describe the source of thermal energy, the direction of energy and matter flow, and the role of gravity in the process.

The answer would be

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.

The answer for this is a