Overview of The States of Matter
Matter is made up of minuscule particles which, governed by the thermodynamic conditions, will interact to form one of several possible macroscopic phases: solid, liquid or gas. Although technically, the phases of matter may also include such variations as plasmas and Bose-Einstein condensates among others, in general chemistry our discussion will be concerned with the three phases common on the earth. Solids have a fixed volume and shape. Liquids have a fixed volume but take the shape of the portion of the container they occupy, and gases assume the shape and volume of the container they occupy. Our concern will be with the intrinsic properties of each phase and the thermodynamic factors underlying the transformation of one state of matter to another in phase change processes.
The States of Matter on the MCATPhase equilibria diagrams, the behavior of real gases, and the vapor pressure related phenomena are perenial MCAT favorites. With liquids, surface tension and capillary action have both shown up on many exams. Occasionally, an MCAT will expect students at least to be familiar with the terminology of crystal structure in solids. In other words, as core general chemistry knowledge, you should expect to see questions from this material on your exam.