alkaline-earth element
111Valence (chemistry) — For other uses, see Valence (disambiguation). In chemistry, valence, also known as valency or valence number, is a measure of the number of bonds formed by an atom of a given element. Valence can be defined as the number of valence bonds[1] a… …
112Uranium — (pronEng|jʊˈreɪniəm) is a silvery gray metallic chemical element in the actinide series of the periodic table that has the symbol U and atomic number 92. It has 92 protons and 92 electrons, 6 of them valence electrons. It can have between 141 and …
113barium — /bair ee euhm, bar /, n. Chem. a whitish, malleable, active, divalent, metallic element, occurring in combination chiefly as barite or as witherite. Symbol: Ba; at. wt.: 137.34; at. no.: 56; sp. gr.: 3.5 at 20°C. [1800 10; BAR(YTES) + IUM] * * *… …
114magnesium — /mag nee zee euhm, zheuhm, shee euhm/, n. Chem. a light, ductile, silver white, metallic element that burns with a dazzling white light, used in lightweight alloys, flares, fireworks, in the manufacture of flashbulbs, optical mirrors, and… …
115nitride — /nuy truyd, trid/, n. Chem. a compound, containing two elements only, of which the more electronegative one is nitrogen. [1840 50; NITR + IDE] * * * ▪ chemical compound Introduction any of a class of chemical compounds in which nitrogen is… …
116Lutetium — (pronEng|ljuːˈtiːʃiəm) is a chemical element with the symbol Lu and atomic number 71. A silvery white rare metal, lutetium is the heaviest member of the rare earth group.Parker, Sybil P., ed. Dictionary of Scientific and Technical Terms. 3rd ed.… …
117barium — A metallic, alkaline, divalent earth element; atomic no. 56, atomic wt. 137.327. Insoluble salts are often used in radiology as contrast media. [G. barys, heavy] b. chloride …
118strontium — strontic /stron tik/, adj. /stron shee euhm, sheuhm, tee euhm/, n. Chem. a bivalent, metallic element whose compounds resemble those of calcium, found in nature only in the combined state, as in strontianite: used in fireworks, flares, and tracer …
119ion-exchange reaction — ▪ chemical reaction Introduction any of a class of chemical reactions between two substances (each consisting of positively and negatively charged species called ions (ion)) that involves an exchange of one or more ionic components.… …
120Calcium — A mineral found mainly in the hard part of bones. Bones serve as a storage area for calcium. Calcium is added to bones by cells called osteoblasts. It is removed from bones by cells called osteoclasts. When children consume calcium, they absorb… …
