What volume (L) of O2 gas is necessary to produce 12.3L of CO2?

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.

Dsolubility let me know if you have any other questions for chemistry

12 is probably the typical age for a first kiss but i think its to young.