Percent composition of potassium in K20?

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.

Answer ozone (o3) is made of three atoms of oxygen, it is a molecule;

The percentage of the rock record is 66%plz mark me brainliest! hope this !