phase+diagrams

A phase diagram, sometimes called a PT diagram, is a graph of pressure versus temperature that depicts the transitions between solid, liquid, and gas phases of a material.



There are two important points on a phase diagram:


 * __triple point__: this is a specific temperature and pressure where all three phases of matter can co-exist and will be in equilibrium.
 * __critical point__: this point is where the substance becomes a //supercritical fluid//, meaning the gas and liquid phases are indistinguishable.

Here is a sample phase diagram for carbon dioxide.

Go here for a periodic table of phase diagrams.