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acid rain

(Encyclopedia)acid rain or acid deposition, form of precipitation (rain, snow, sleet, or hail) containing high levels of sulfuric or nitric acids (pH below 5.5–5.6). Produced when sulfur dioxide and various nitro...

nitric acid

(Encyclopedia)nitric acid, chemical compound, HNO3, colorless, highly corrosive, poisonous liquid that gives off choking red or yellow fumes in moist air. It is miscible with water in all proportions. It forms an a...

tracer

(Encyclopedia)tracer, an identifiable substance used to follow the course of a physical, chemical, or biological process. In chemistry the ideal tracer has the same chemical properties as the molecule it replaces a...

organic chemistry

(Encyclopedia)organic chemistry, branch of chemistry dealing with the compounds of carbon. While it is only the fourteenth most common element on earth, carbon forms by far the greatest number of different compound...

amino acid

(Encyclopedia)CE5 General formula of an amino acid CE5 Peptide bond between two molecules of the amino acid alanine amino acid əmēˈnō [key], any one of a class of simple organic compounds containin...

cuttlefish

(Encyclopedia)cuttlefish, common name applied to cephalopod mollusks that have 10 tentacles, or arms, 8 of which have muscular suction cups on their inner surface and 2 that are longer and can shoot out for graspin...

lanthanum

(Encyclopedia)lanthanum lănˈthənəm [key] [Gr.,=to lie hidden], metallic chemical element; symbol La; at. no. 57; at. wt. 138.90547; m.p. about 920℃; b.p. about 3,460℃; sp. gr. 6.19 at 25℃; valence +3. Lan...

uric acid

(Encyclopedia)uric acid yo͝orˈĭk [key], white, odorless, tasteless crystalline substance formed as a result of purine degradation in man, other primates, dalmatians, birds, snakes, and lizards. The last three gr...

catalyst

(Encyclopedia)catalyst, substance that can cause a change in the rate of a chemical reaction without itself being consumed in the reaction; the changing of the reaction rate by use of a catalyst is called catalysis...

automobile

(Encyclopedia)CE5 Automobile chassis CE5 Two views of a six-cylinder automobile engine automobile, self-propelled vehicle used for travel on land. The term is commonly applied to a four-wheeled vehicle desig...