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tin

(Encyclopedia)tin, metallic chemical element; symbol Sn [Lat. stannum]; at. no. 50; at. wt. 118.710; m.p. 231.9681℃; b.p. 2,270℃; sp. gr. 5.75 (gray), 7.3 (white); valence +2 or +4. Tin exhibits allotropy; abov...

hydrazine

(Encyclopedia)hydrazine hīˈdrəzēnˌ [key], chemical compound, formula NH2NH2, m.p. 1.4℃, b.p. 113.5℃, specific gravity 1.011 at 15℃. It is very soluble in water and soluble in alcohol. At ordinary tempera...

bleaching powder

(Encyclopedia)bleaching powder, white or nearly white powder that is usually a mixture of calcium chloride hypochlorite, CaCl(OCl); calcium hypochlorite, Ca(OCl)2; and calcium chloride, CaCl2. Sometimes called chlo...

Periodic Table of the Elements: Sodium

(Encyclopedia)Periodic Table of the Elements: Sodium ...

aqua regia

(Encyclopedia)aqua regia rēˈjēə [key] [Lat.,=royal water], corrosive, fuming yellow liquid prepared by mixing one volume of concentrated nitric acid with three to four volumes of concentrated hydrochloric acid....

beryllium

(Encyclopedia)beryllium bərĭlˈēəm [key] [from beryl ], metallic chemical element; symbol Be; at. no. 4; at. wt. 9.01218; m.p. about 1,278℃; b.p. 2,970℃ (estimated); sp. gr. 1.85 at 20℃; valence +2. Ber...

ammonium group

(Encyclopedia)ammonium group, in chemistry, a positively charged nitrogen atom joined by single bonds to four other atoms or groups. The simplest ammonium group, NH4+, is formed by protonation of ammonia, NH3, e.g....

bleaching

(Encyclopedia)bleaching, process of whitening by chemicals or by exposure to sun and air, commonly applied to textiles, paper pulp, wheat flour, petroleum products, oils and fats, straw, hair, feathers, and wood. C...

acids and bases

(Encyclopedia)acids and bases, two related classes of chemicals; the members of each class have a number of common properties when dissolved in a solvent, usually water. Another theory that provides a very broad ...

lithium

(Encyclopedia)lithium lÄ­thˈēəm [key] [Gr.,=stone], metallic chemical element; symbol Li; at. no. 3; interval in which at. wt. ranges 6.938–6.997; m.p. about 180.54℃; b.p. about 1,342℃; sp. gr. .534 at 20â...