Meaning of VALENCE in English

VALENCE

ˈvālən(t)s noun

( -s )

Etymology: Late Latin valentia power, capacity, from Latin valent-, valens (present participle of valēre to be strong) + -ia -y — more at wield

1.

a. : the degree of combining power of an element or radical : the number of atoms of hydrogen, sodium, fluorine, or other univalent element with which an atom of the element or a molecule of the radical will combine by means of bonds or for which it can be substituted or with which it can be compared : the oxidation state of an element in a compound

potassium has a valence of one because a gram atom combines with a gram atom of hydrogen to form potassium hydride KH or with a gram atom of fluorine to form potassium fluoride KF

iron has a variable valence ; two in ferrous chloride FeCl 2 and three in ferric chloride FeCl 3

— see covalence , electrovalence ; compare coordinate bond , polar valence 2

b. : a unit of valence

the four valences of carbon

2.

a. : relative capacity to unite, react, or interact (as with antigens or a biological substrate)

b. : the degree of attractiveness an individual, activity, or object possesses as a behavioral goal

the group may have a positive valence for member A because he has friends in it — Neal Gross & W.E.Martin

Webster's New International English Dictionary.      Новый международный словарь английского языка Webster.