bivalente

Bivalente is an adjective used in several scientific fields to describe something with a valence of two. In Romance languages such as Spanish and Portuguese, it corresponds to the English term divalent. The concept denotes a two-value capacity, typically relating to bonding, charge, or pairing, and is closely linked to ideas of valence, oxidation state, and coordination.

In chemistry, a bivalent element or ion has a valence of two and can form two chemical bonds. Examples include the oxide ion O2-, the calcium ion Ca2+, and many sulfur-containing species in divalent compounds. Some transition metals also commonly display a two-plus oxidation state, such as iron(II) Fe2+. The descriptor helps classify reactivity and bonding patterns in inorganic and organic compounds.

In biology, the term is used to describe the paired homologous chromosomes during the early stages of meiosis, specifically prophase I. A bivalent consists of two homologous chromosomes, each composed of two sister chromatids, held together by synapsis and chiasmata. The formation of bivalents enables crossing over and genetic recombination, contributing to genetic diversity in offspring.

Usage notes: the term can appear in linguistics to denote predicates with two obligatory arguments in some frameworks, though this usage is less universal. Etymology traces to Latin bi- meaning “two” and valere meaning “to be strong” or “to be worth,” reflecting the two-valued nature of the concept.