Etymology
Advertisement
valence (n.)
early 15c., "extract, preparation," from Latin valentia "strength, capacity," from valentem (nominative valens) "strong, stout, vigorous, powerful," present participle of valere "be strong" (from PIE root *wal- "to be strong"). Chemistry sense of "relative combining capacity of an element with other atoms when forming compounds or molecules" is recorded from 1884, from German Valenz (1868), from the Latin word. Related: Valency.
Related entries & more 
Advertisement
multivalent (adj.)

1869, originally in chemistry, "having more than one degree of valency," from multi- "many" + -valent (see valence in the chemistry sense). Related Multivalence.

Related entries & more 
bivalent (adj.)
1864, of chemicals, 1899, of chromosomes, from bi- + -valent (see valence in the chemistry sense).
Related entries & more 
covalent (adj.)

1927, from covalence "the linking of two atoms by a shared pair of electrons" (1919), from co- + valence.

Related entries & more 
polyvalent (adj.)

"capable of combining partly with one element, partly with another," 1881, from poly- + -valent (see valence in the chemistry sense). Coined by German chemist Emil Erlenmeyer, who also designed the flask that bears his name.

Related entries & more 
Advertisement
valance (n.)
piece of hanging, decorative drapery, mid-15c., of uncertain origin, probably from Anglo-French *valaunce, valence, from valer "go down, let down," variant of Old French avaler "descend, go down;" or possibly from the plural of Old French avalant, from present participle of avaler "go down." The notion is of something "hanging down." Not now considered to be from the name of Valence in southwestern France, which is from the Roman personal name Valentius. Related: Valenced.
Related entries & more 
ferric (adj.)
1799, "pertaining to or extracted from iron," from Latin ferrum "iron" (see ferro-) + -ic. Especially of iron with a valence of three.
Related entries & more 
plumbous (adj.)

1680s, "leaden;" 1854 in the chemistry sense of "containing lead" (especially in a low valence), from Latin plumbosus "full of lead," from plumbum (see plumb (n.)).

Related entries & more 
ferrous (adj.)
"pertaining to or containing iron," 1865, from Latin ferreus "made of iron," from ferrum "iron" (see ferro-). In chemistry, "containing iron," especially with a valence of two. Contrasted with ferric.
Related entries & more 
nitrous (adj.)

c. 1600, "of nitre, pertaining to nitre," from Latin nitrosus, from nitrum (see nitre). The more precise use in chemistry (designating a compound in which the nitrogen has a lower valence than the corresponding nitric compound) is from 1780s. Middle English had nitrose "nitrous in quality; bitter, sour" (early 15c.). Nitrous oxide "laughing gas" is attested from 1800.

When inhaled it produces unconsciousness and insensibility to pain; hence it is used as an anesthetic during short surgical operations. When it is breathed diluted with air an exhilarating or intoxicating effect is produced under the influence of which the inhaler is irresistibly impelled to do all kinds of silly and extravagant acts; hence the old name of laughing-gas. [Century Dictionary, 1895]
Related entries & more