Columbia Encyclopedia

(Encyclopedia) Murcia, city (1990 pop. 322,911), capital of the autonomous community and coextensive prov. of Murcia, SE Spain, on the Segura River. The city lies in one of the finest irrigated garden regions in Spa...

(Encyclopedia) Akita äˈkētä [key], city, capital of Akita prefecture, NW Honshu, Japan, on the Sea of Japan. A producer of petroleum products and chemicals, Akito city also has a lar...

(Encyclopedia) Manabe, Syukuro, 1931– , Japanese climatologist and meteorologist, D.Sc. University of Tokyo, 1958. Manabe has been instrumental in the development of...

(Encyclopedia) calcium carbonate, CaCO3, white chemical compound that is the most common nonsiliceous mineral. It occurs in two crystal forms: calcite, which is hexagonal, and aragonite, which is rhombohedral. Calci...

(Encyclopedia) water gas, colorless poisonous gas that burns with an intensely hot, bluish (nearly colorless) flame. The gas is a mixture of carbon monoxide and hydrogen with very small amounts of other gases, e.g.,...

(Encyclopedia) polymorphism, of minerals, property of crystallizing in two or more distinct forms. Calcium carbonate is dimorphous (two forms), crystallizing as calcite or aragonite. Titanium dioxide is trimorphous;...

(Encyclopedia) uranium yo͞orāˈnēəm [key], radioactive metallic chemical element; symbol U; at. no. 92; mass number of most stable isotope 238; m.p. 1,132℃; b.p. 3,818℃; sp. gr. 19.1 at 25℃; valence +3, +4...

(Encyclopedia) diffusion, in chemistry, the spontaneous migration of substances from regions where their concentration is high to regions where their concentration is low. Diffusion is important in many life process...

(Encyclopedia) Fischer-Tropsch process fĭshˈər-trōpsh [key], method for the synthesis of hydrocarbons and other aliphatic compounds. Synthesis gas, a mixture of hydrogen and carbon monoxide, is reacted in the pr...

(Encyclopedia) food preservation, methods of preparing food so that it can be stored for future use. Because most foods remain edible for only a brief period of time, people since the earliest ages have experimented...