the element magnesium, Mg, has three common isotopes: 24Mg, 25Mg,26Mg. The difference between these three isotopes is

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 is 4 i don't know if its right let me see.