In the field of chemistry and of the physical the concept of ion to name an atom or a group of atoms that gets an electric charge by winning or losing one or more electrons .
To understand what an ion is, it is convenient to focus earlier on the definition of other terms. It is important to know, first of all, that a atom it is a particle that cannot be divided by chemical methods, which has a nucleus that is surrounded by electrons (elementary particles that have a negative electrical charge).
An atom, in this way, presents a nucleus with electrons around it. When, when adding or releasing an electron, the atom acquires an electric charge, it is called an ion. The ions, therefore, are electrically charged particles .
Is called ionization to the process that develops an atom or a molecule when transformed into an ion. This change occurs when, starting from a neutral state, the atom gains or loses electrons.
It is possible to differentiate between two types of ions: cations and the anions . A cation It is an ion that has a positive electrical charge (for having lost electrons), while a anion It is an ion that has a negative electrical charge (since it gained electrons).
Ions are also classified according to the amount of atoms they have. When the ion has a single atom, it is a monoatomic ion . However, if the ion has at least two atoms, it is called polyatomic ion .