In my last post I discussed matter and its physical and chemical properties very generally. In this post I will get a little deeper into what matter is and probably repeat something we all know but wouldn't hurt to be reminded of, which is how matter is classified. As we learned in some of our earliest science classes, there are three main, basic phases of matter. The reason why I say "main, basic" phases is because these three phases are phases that we all know and are familiar with; however, matter has a number of other phases, a fourth of which many know to be plasma. Further, the other phases I am referring to are abundant when considering "modern" phases of matter, as opposed to the "classical" states that we will be discussing. If you don't know what I mean by this, don't worry about it because it isn't important for the time being.
This post will be relatively short because it is a simple review of a very simple concept, and we will be moving on to more intricate things for the next post. The three phases of matter that we are all familiar with are solid, liquid, and gas. Though it's easy to repeat these phases off of the top of our heads, it is more important that we know what makes each phase its own phase, i.e. what differentiates each phase from the next one. A solid is a phase of matter that has a fixed shape as well as a fixed volume. A liquid, on the other hand, does not have the same fixed shape that a solid does, but its volume is fixed. And finally, a gas does not have a fixed shape and also does not have a fixed volume (Masterton and Hurley 2015).
Before ending this post so soon, it's helpful to know that matter is also commonly classified in another way. Matter can be broken down also by composition, a term we discussed earlier, synonymous with "constituents." When broken down in this particular way, there are two groups used in the classification of matter. First, there are pure substances. Pure substances each have a composition that is fixed; as well, they have properties that are unique. Pure substances are made of either elements or compounds, which we will discuss in an upcoming post. And secondly, there are mixtures, which are composed of more than a single substance. Mixtures can be either heterogenous or homogenous, two terms which will also be defined in an upcoming post, but whose definition you can probably already infer from the prefixes "hetero" and "homo" (Masterton and Hurley 2015).
Understandably, there is not too much to study in this post as the information is very basic. If you find this to be true for you, let this post serve as a reminder to you of something that you must take note of for the MCAT. Yes, it is simple stuff, but remember also that the MCAT is a difficult test and the only way to do well is to know and understand each concept precisely.
A prospective medical student, looking to help others succeed.