valence

(vāˈləns) also va·len·cy (-lən-sē)

1. Chemistry
   a. The combining capacity of an atom or radical determined by the number of electrons that it will lose, add, or share when it reacts with other atoms.
   b. A positive or negative integer used to represent this capacity: The valences of copper are 1 and 2.
2. The number of binding sites of a molecule, such as an antibody or antigen.
3. The ability of a substance to interact with another or to produce an effect.
4. Psychology The degree of attraction or aversion that an individual feels toward a specific object or event.
5. Linguistics The number of arguments that a lexical item, especially a verb, can combine with to make a syntactically well-formed sentence, often along with a description of the categories of those constituents. Intransitive verbs (appear, arrive) have a valence of one—the subject; some transitive verbs (paint, touch), two—the subject and direct object; other transitive verbs (ask, give), three—the subject, direct object, and indirect object.
6. The capacity of something to unite, react, or interact with something else: “I do not claim to know much more about novels than the writing of them, but I cannot imagine one set in the breathing world which lacks any moral valence” (Robert Stone).

(və-läɴsˈ, vă-)