The Greek word kathión came to English as cation, which in our language derived from cation. The term is used with reference to an ion that has a positive charge.
To understand precisely what a cation is, therefore, we must analyze the notions that are mentioned in its definition. A cation is a class of ion: an atom, or set of atoms, that gains electrical charge through the gain or loss of electrons.
Let us remember that atoms are those particles that cannot be divided through a chemical procedure and that are composed of electrons (elementary particles that have a negative electrical charge) that surround a nucleus.
The ion that has a positive electric charge when adding or losing electrons, in short, is a cation. When cations establish an ionic bond with anions (ions that have a negative electrical charge), they form a salt. These salts are usually the result of the chemical reaction that is generated between a base (which provides the cation) and an acid (which provides the anion).
The salt that is used to flavor food is an example of the product of this type of reactions that involve a cation and an anion. In this case, the sodium hydroxide base provides the cation by reacting with the hydrochloric acid, which adds the anion. The result is the product known as sodium chloride: table salt.
It is important to mention that cations are found in the human body through potassium, sodium and other elements that constitute ionized salts.
The science has documented the existence of a very large number of cations, each with its traditional (or name old), its symbol and its name IUPAC. The latter acronym corresponds to the International Union of Pure and Applied Chemistry, whose original name in English is International Union of Pure and Applied Chemistry; It is a group made up of national societies dedicated to chemistry, with the power to develop standards for naming chemical compounds.
By looking at the list of the most frequent cations, we can make a distinction between the simple ones and the polyatomic ones; in the first group are the following (according to the nomenclature recognized by the IUPAC): aluminum, barium, beryllium, calcium, chromium III, cobalt II, copper II, gallium, helium, hydrogen, lead, magnesium, lithium, manganese II, nickel II, potassium, silver, sodium, strontium, tin II and zinc.
According to DigoPaul, some of the most common polyatomic cations, for their part, are ammonium, hydronium, nitronium and mercury I; the only one of these that has a traditional name different from that provided by the IUPAC is the last one, which is known as the mercurous cation.
It is important to note that the nomenclature is one of the fundamental points of science, since it allows to standardize the names of the various discoveries to facilitate their study and dissemination internationally, as well as over time. In the case of cations, the IUPAC recommended in 2005 that all those that, according to their old or traditional nomenclature, had the ending “-ico” or “-oso” stop being used, with the sole exception of oxoacids.
In biology, cations have several important roles; for example, the transport of various organic molecules into cells is carried out through cell membranes whose electrochemical potentials are maintained by concentration gradients of various cations. On the other hand, they promote the transmission of nerve impulses and the contraction of muscles, and participate in catalytic functions since they are found in the active centers of many enzymes.