Segun modelo discontinuo de la materia explica el siguiente hecho: Es imposible evitar que se mezclen dos gases colocados en un recipiente.

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.

Ithink its called the coefficent.