What are some different careers available for people that want to study atoms and molecules?

Copper, silver, aluminum, cobalt, chromium, mercury 

The real answer is keeping the world healthy so we won’t die

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.