A solid to a liquid, the boiling of water, solid the water molecules vibrate condensed but as a liquid they are still isolated in a controlled area and also reflect off one another more, liquid to a gas they do not and move freely until condensation occurs
A scientific theory focuses on explaining a phenomenon, while a law will have a generalised statement about said phenomenon. Often times, we use laws to help us develop theories. =)
I think H would be one of them because it as a gas is H2
