The notion of system in chemistry

Abstract

One of the first things that comes to mind when thinking about chemistry is probably the idea of a chemical reaction. In simple terms, one can imagine a process in which two species (atoms or molecules) react giving rise to a third one completely different. Despite the specificity of the chemical nature of these processes, generally speaking, reductionist laws or traditional Cartesian approaches used in physics remain valid in certain chemical processes.

In most cases, however, chemical processes present a so called complex behavior under certain conditions. To this end, the systems must be open to the exchange of information, matter and energy with the environment, so that this exchange will allow them to be kept outside the state of thermodynamic equilibrium (basically the state in which "things happen"). Out of equilibrium, open systems dynamic is usually described by non-linear terms. Therefore, the possibility of multiple states or paths by which the system can evolve becomes a key feature. In other words, there is a change of focus from being to becoming, using prigoginian words.