To determine the number of protons an element has what do you look at on the periodic table?

D. most models represent a real world object in a simpler way

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.