Cationi

Cationi is the plural form of cation in several languages and is often encountered in discussions of ionic chemistry. A cation is a positively charged ion produced when an atom or molecule loses electrons. In solution, cations migrate toward the negative electrode and contribute to electrical conductivity. Monoatomic cations arise from single elements, such as Na+, K+, Ca2+, and Fe3+. Polyatomic cations consist of a group of atoms with an overall positive charge, with ammonium (NH4+) as a common example.

Cations form by oxidation, protonation, or complexation, and their charge and ionic radius influence hydration, lattice energies of salts, and mobility in solution. Higher charge and smaller radius yield higher charge density, leading to stronger interactions with solvent and neighboring ions.

Cations are essential in salts, minerals, and biological systems. In biology, key cations include sodium, potassium, calcium, magnesium, and ammonium. In coordination chemistry, metal cations form complexes with ligands, affecting color, reactivity, and catalysis. In electrochemical and geochemical contexts, cation exchange and ion migration are important processes.

Naming and notation: Cations are usually named as the element name followed by "ion" (for example, sodium ion, calcium ion), or with oxidation state in parentheses for transition metals (iron(II) ion). Polyatomic cations have fixed names such as ammonium. The term "cationi" appears as a plural form in some languages.