a town in SE France, on the River Rhône. Pop: 64 260 (1999)
Valence in American English
(vaˈlɑ̃s)
city in SE France: pop. 63,000
valence in American English
(ˈveɪləns)
Word forms: pluralˈvalencies
noun Chemistry
1.
the capacity of an element or radical to combine with another to form molecules, as measured by the number of hydrogen or chlorine atoms which one radical or one atom of the element will combine with or replace (e.g.: oxygen has a valence of two, i.e., one atom of oxygen combines with two hydrogen atoms to form the watermolecule, H2O)
2.
any of the units of valence which a particular element may have
Also ˈvalencyWord forms: pluralˈvalencies
Word origin
LL valentia, worth, capacity < L, vigor < valens, prp. of valere, to be strong: see value
All related terms of 'valence'
valency
a property of atoms or groups, equal to the number of atoms of hydrogen that the atom or group could combine with or displace in forming compounds
valence band
a range of energies associated with the quantum states of electrons in a crystalline solid . In a semiconductor or an insulator there is a valence band containing many states, most of which are occupied . Above this is a forbidden band with only a few isolated states caused by impurities . Above this is a conduction band containing many states most of which are empty . In a metal there is a continuous valence-conduction band
valence electrons
the orbital electrons in the outermost shell of an atom which largely determine its properties
valence-conduction band
a range of energies associated with the quantum states of electrons in a crystalline solid. In a semiconductor or an insulator there is a valence band containing many states, most of which are occupied . Above this is a forbidden band with only a few isolated states caused by impurities . Above this is a conduction band containing many states most of which are empty . In a metal there is a continuous valence-conduction band
coordination complex
one of a number of complex compounds in which an atom or group of atoms is bound to the central atom by a shared pair of electrons supplied by the coordinated group and not by the central atom