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Holocaust

(Encyclopedia)Holocaust hŏlˈəkôstˌ, hōˈlə– [key], name given to the period of persecution and extermination of European Jews by Nazi Germany. Romani (Gypsies), homosexuals, Jehovah's Witnesses, the disabl...

coal gas

(Encyclopedia)coal gas, gas obtained in the destructive distillation of soft coal, as a byproduct in the preparation of coke. Its composition varies, but in general it is made up largely of hydrogen and methane wit...

erythema

(Encyclopedia)erythema ĕrˌəthēˈmə [key], more or less diffuse redness of the skin due to concentration of an abnormally large amount of blood within the small vessels of the skin (hyperemia), as in burns. Ery...

heparin

(Encyclopedia)heparin hĕpˈərĭn [key], anticoagulant produced by cells in many animals. A polysaccharide, heparin is found in the human body and occurs in greatest concentration in the tissues surrounding the ca...

cream of tartar

(Encyclopedia)cream of tartar, white crystalline powder. Chemically it is potassium hydrogen tartrate, KC4H5O6, the acidic potassium salt of tartaric acid. It is used as the leavening agent in baking powders. An im...

interstellar matter

(Encyclopedia)interstellar matter, matter in a galaxy between the stars, known also as the interstellar medium. The interstellar gas, which constitutes about 99% of the interstellar matter, consists mostly of hyd...

photosynthesis

(Encyclopedia)photosynthesis fōˌtōsĭnˈthəsĭs [key], process in which green plants, algae, and cyanobacteria utilize the energy of sunlight to manufacture carbohydrates from carbon dioxide and water in the pr...

oxidation and reduction

(Encyclopedia)oxidation and reduction, complementary chemical reactions characterized by the loss or gain, respectively, of one or more electrons by an atom or molecule. Originally the term oxidation was used to re...

electrolyte

(Encyclopedia)electrolyte ĭlĕkˈtrəlītˌ [key], electrical conductor in which current is carried by ions rather than by free electrons (as in a metal). Electrolytes include water solutions of acids, bases, or s...

chelating agents

(Encyclopedia)chelating agents kēˈlātĭng [key]. Certain organic compounds are capable of forming coordinate bonds (see chemical bond) with metals through two or more atoms of the organic compound; such organic ...