6. Positive uses of radioactive decay used by humans would not include a. Cancer treatment.
b. Killing microbes.
c. Carbon dating artifacts.
d. All of the above are actually positive.

If you open the bottle of perfume then nothing but the smell will come out of it and yes it is a type of gas smell because it’s say it in english so i can understand better and you

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 answers is a nuclear changes