Which of the following is not a physical change?

dissolving salt in water

baking a cake

melting wax

freezing water

Most likely a is the answer - because  you generate   38 atp's but also consume an atp.   each atp gives approx. less than 4 kcal so probably a is the closest answer.

Ithink its solid. 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.

Ibelieve it is b. proton.hope my answer has you : )