anionico

Anionico is a term used in several Romance languages to describe matters related to anions, negatively charged ions. In English, the corresponding adjective is anionic. The concept derives from anions, atoms or molecules that carry a net negative electric charge. Anions form when atoms gain electrons or when acids dissociate to release their conjugate bases.

In chemical systems, anions are key participants in acid-base chemistry, salts, and electrolyte solutions. Their negative charge causes attraction to cations and influences their behavior in solution, hydration, and coordination with metals and solvents. Common inorganic anions include chloride (Cl−), sulfate (SO4^2−), nitrate (NO3−), and phosphate (PO4^3−); organic examples include acetate (CH3COO−) and benzoate (C6H5COO−).

Applications of anionic species are widespread. Anionic surfactants, such as sodium lauryl sulfate, are used in detergents and personal care products. Anionic exchange resins are employed to remove unwanted anions in water treatment and food processing. In polymer chemistry, anionic polymerization is a method for making polymers with controlled molecular weight distributions. In biology and medicine, anions participate in signaling, electrolyte balance, and various metabolic processes.

The term is often used descriptively for materials or processes that bear negative charge or interact with anions, such as anionic membranes or anionic catalysts.