The oxidation state or oxidation number is a number given to each based on the charge. It is the an atom would have if all shared were assigned to the with a attraction for those electrons.

Ithink it is quantity of plants

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 correct answer should be "electrons orbit the nucleus in circular motions exactly as shown on the classic bohr model."