Calculate the mass in grams of 0.0420 moles of copper

4.2 grams i think i hope this helps

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.