An electron has a mass of 1) 1 amu 2) -1 amu 3) 0 amu

Electron has a mass of about 9.10938215 × 10 - 31 kg

I will assume 2

Coal i believe hope this

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.