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valence, in chemistry

(Encyclopedia)valence, combining capacity of an atom expressed as the number of single bonds the atom can form or the number of electrons an element gives up or accepts when reacting to form a compound. Atoms are c...

sodium chloride

(Encyclopedia)sodium chloride, NaCl, common salt. Salt is important in many ways. It is an essential part of the diet of both humans and animals and is a part of most animal fluids, such as blood, sweat, and te...

Pigalle, Jean Baptiste

(Encyclopedia)Pigalle, Jean Baptiste zhäN bätēstˈ pēgälˈ [key], 1714–85, French sculptor. His skill embraced a wide range, from small works appealing to the taste of the court to large and elaborate tombs....

Puy de Dôme

(Encyclopedia)Puy de Dôme, extinct volcano of the Massif Central and the second highest peak (4,806 ft/1,465 m) of the Auvergne Mts., central France, W of Clermont-Ferrand. Crops are raised on the lower slopes; th...

electromotive series

(Encyclopedia)electromotive series, list of metals whose order indicates the relative tendency to be oxidized, or to give up electrons (see oxidation and reduction); the list also includes the gas hydrogen. The ele...

sextant

(Encyclopedia)CE5 Sextant sextant, instrument for measuring the altitude of the sun or another celestial body; such measurements can then be used to determine the observer's geographical position or for other n...

halogen

(Encyclopedia)halogen hălˈəjĕn [key] [Gr.,=salt-bearing], any of the chemically active elements found in Group 17 of the periodic table; the name applies especially to fluorine (symbol F), chlorine (Cl), bromin...

Martin, Archer John Porter

(Encyclopedia)Martin, Archer John Porter, 1910–2002, English biochemist, educated at Cambridge. From 1938 to 1946 he carried on chemical research in the laboratories of the Wool Industries Association at Leeds, Y...

Franklin, Ann Smith

(Encyclopedia)Franklin, Ann Smith, 1696–1763, American printer; sister-in-law of Benjamin Franklin. After the death in 1735 of her husband, James Franklin, she carried on his commercial printing business, in Newp...