What would happen if you put a balloon on earth And brought it to the moon with lower atmospheric pressure it would do what? 1: Expand
2: Shrink
3: Stay the same size with the same internal pressure
4: Stay the same size but with a different internal pressure

Well to my expert knowledge and my exquisite calculations i think the the negative ion # 412 is the key to sucess

It is a mixture. simply put, a compound must be pure, that is, of only one chemical structure and composition. a mixture is made of different chemical substances (i.e. elements, molecules, compounds) that are not chemically bonded to each other, but instead physically grouped together, as in the case of gasoline (a homogeneous solution).