Michael has a substance that he puts in container 1. The substance has a volume of 5 cubic meters. He then puts it in container 2 and it now has a volume of 10 cubic meters. In which phases(s) is the substance?
Do you know how large a cubic metre is? The substance is CLEARLY in the gaseous phase.......
On the other hand, solids, and liquids, are largely incompressible, and have definite volumes and densities.
Here, the volume of the substance GREATLY expanded, i.e. twofold. The stuff must be a gas.