Yksiarvoisia

Yksiarvoisia is Finnish plural adjective form of yksiarvoinen, meaning having a single value. The term is used in science and mathematics to describe entities that possess only one value or valence. Grammatically, yksiarvoisia is the partitive plural form and can modify plural nouns, for example yksiarvoisia ioneja.

In chemistry, yksiarvoisia refers to monovalent ions or atoms with valence one. Typical examples include H+, Na+, K+ (positive monovalent ions) and Cl− (negative monovalent ion). Monovalent species tend to form one bond or participate in one electron-transfer step in ionic compounds, such as NaCl or HCl. The concept is contrasted with kaksiarvoisia (divalent) or kolmiarvoisia (trivalent) species, which have valences of two or three, respectively.

In mathematics, yksiarvoisia describes single-valued functions—functions that assign exactly one output to each input. This usage helps distinguish from multivalued relations or inverse mappings. For example, the function f(x) = x^2 is single-valued; its inverse relation is multivalued, since x = ±√y yields two possible inputs for certain outputs.

Etymology and grammar: the term combines yksi (“one”) and arvoinen (“valued”/having value). The suffix -isia marks the plural partitive form in Finnish adjectives. The related noun forms include yksiarvoisuus (monovalency or single-valuedness) and yksiarvoinen (monovalent, univalent).

See also: valenssi (valence), yksiarvoisuus, monovalentti.