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agronomy

(Encyclopedia)agronomy əgrŏnˈəmē [key], branch of agriculture dealing with various physical and biological factors—including soil management, tillage, crop rotation, breeding, weed control, and climate—rel...

hematite

(Encyclopedia)hematite hĕmˈətīt [key], mineral, an oxide of iron, Fe2O3, containing about 70% metal, occurring in nature in red to reddish-brown earthy masses and in steel-gray to black crystalline forms. Hemat...

chloroprene

(Encyclopedia)chloroprene klōrˈəprēnˌ [key] or 2-chloro-1,3-butadiene, colorless liquid organic compound used in the synthesis of neoprene and certain other rubbers. The structure of the chloroprene molecule i...

iridescence

(Encyclopedia)iridescence ĭrˌədĕsˈəns [key], exhibition of rainbowlike colors on a surface. It usually results from interference when light composed of different wavelengths is reflected from the superficial ...

solvent

(Encyclopedia)solvent, constituent of a solution that acts as a dissolving agent. In solutions of solids or gases in a liquid, the liquid is the solvent. In all other solutions (i.e., liquids in liquids or solids i...

ambergris

(Encyclopedia)ambergris ămˈbərgrēs [key], waxlike substance originating as a morbid concretion in the intestine of the sperm whale. Lighter than water, it is found floating on tropical seas or cast up on the sh...

sodium thiosulfate

(Encyclopedia)sodium thiosulfate, Na2S2O3, colorless crystalline compound that is more familiar as the pentahydrate, Na2S2O3·5H2O, an efflorescent, monoclinic crystalline substance also called sodium hyposulfite o...

inorganic chemistry

(Encyclopedia)inorganic chemistry, the study of all the elements and their compounds with the exception of carbon and its compounds, which fall under the category of organic chemistry. Inorganic chemistry investiga...

anglesite

(Encyclopedia)anglesite ăngˈgləsīt [key], pale green, blue, yellow-to-white, or colorless mineral, a sulfate of lead, PbSO4, that is formed by oxidation of galena, crystallizing in the orthorhombic system and o...

Garden, Alexander

(Encyclopedia)Garden, Alexander, c.1730–1791, Scottish-American naturalist and physician, b. Aberdeenshire, Scotland. He settled in Charleston, S.C., where he collected mineral, plant, and animal specimens and di...