|
Valence Cathedrale 2004-08-31 003
Valence or valency may refer to: Science * Valence (chemistry), a measure of an element's combining power with other atoms * Degree (graph theory), also called the valency of a vertex in graph theory * Valency (linguistics), aspect of verbs relative to other parts of speech * Valence (psychology) or hedonic tone, the (emotional) value associated with an event, object or situation Places France * Valence, Charente, a commune in the Charente department * Valence, Drôme, Drôme, a commune and prefecture of the Drôme department ** University of Valence, a medieval university * Valence, Tarn-et-Garonne, a commune in the Tarn-et-Garonne department * Canton of Valence, Tarn-et-Garonne department * Arrondissement of Valence, Drôme department * Roman Catholic Diocese of Valence * Valence-d'Albigeois, in the Tarn department * Valence-en-Brie, in the Seine-et-Marne department * Valence-sur-Baïse, in the Gers department * Bourg-lès-Valence, in the Drôme department England * Rive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valence (chemistry)
In chemistry, the valence (US spelling) or valency (British spelling) of an element is the measure of its combining capacity with other atoms when it forms chemical compounds or molecules. Description The combining capacity, or affinity of an atom of a given element is determined by the number of hydrogen atoms that it combines with. In methane, carbon has a valence of 4; in ammonia, nitrogen has a valence of 3; in water, oxygen has a valence of 2; and in hydrogen chloride, chlorine has a valence of 1. Chlorine, as it has a valence of one, can be substituted for hydrogen. Phosphorus has a valence of 5 in phosphorus pentachloride, . Valence diagrams of a compound represent the connectivity of the elements, with lines drawn between two elements, sometimes called bonds, representing a saturated valency for each element. The two tables below show some examples of different compounds, their valence diagrams, and the valences for each element of the compound. Modern definitions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
