Need help reading those phase diagrams given in chemistry class? This video module provides a good review of how to read the diagrams which show the different states of matter and when they transition to another state according to temperature and pressure. Knowing how to read the diagram can tell you whether dealing with solid, liquid or gas. Understand how water may exists in different states according to the geographic location. Also explained is a supercritical fluid which is a combination of liquid and gas. [12:36]