Answer: Ionization is a chemical reaction itself. In chemistry and physics, ionization is a process where electrically neutral atoms become charged atoms by gaining or losing an electron. If an atom (or molecule) loses an electron, it becomes positively charged (aka a cation). Conversely, if an atom gains an electron, it becomes negatively charged (aka an anion). In either case, the electrical balance changes within an atom.
Explanation: A classic example of this would be sodium and chlorine combining to create salt. In this reaction, the sodium atom gives up one electron (making it positively charged) and the chlorine atom receives the electron (making it negatively charged).