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spell

(Encyclopedia)spell, word, formula, or incantation believed to have magical powers. The spell can be used for evil or good ends; if evil, it is a technique of sorcery. Many authorities believe that the spell was th...

concentration

(Encyclopedia)concentration, in chemistry, measure of the relative proportions of two or more quantities in a mixture. The concentration of a solute is very important in studying chemical reactions because it deter...

gunpowder

(Encyclopedia)gunpowder, explosive mixture; its most common formula, called “black powder,” is a combination of saltpeter, sulfur, and carbon in the form of charcoal. Historically, the relative amounts of the c...

alkene

(Encyclopedia)CE5 Alkenes alkene ălˈkēn [key], any of a group of aliphatic hydrocarbons whose molecules contain one or more carbon-carbon double bonds (see chemical bond). Alkenes with only one double bond h...

alkyne

(Encyclopedia)CE5 Alkynes alkyne ălˈkīn [key], any of a group of aliphatic hydrocarbons whose molecules contain one or more carbon-carbon triple bonds (see chemical bond). Alkynes with one triple bond have t...

salt, chemical compound

(Encyclopedia)salt, chemical compound (other than water) formed by a chemical reaction between an acid and a base (see acids and bases). Salts are also prepared by methods other than neutralization. A metal can c...

butadiene

(Encyclopedia)butadiene byo͞otˌədīˈēn [key], colorless, gaseous hydrocarbon. There are two structural isomers of butadiene; they differ in the location of the two carbon-carbon double bonds in the butadiene m...

amulet

(Encyclopedia)amulet ămˈyəlĭt [key], object or formula that credulity and superstition have endowed with the power of warding off harmful influences. The use of the amulet to avert danger and to dispel evil has...

Werner, Alfred

(Encyclopedia)Werner, Alfred, 1866–1919, French-born Swiss chemist, Ph.D. Univ. of Zürich, 1890. Werner was a professor at the Univ. of Zürich from 1893 until his death in 1919. He was awarded the Nobel Prize i...

Arrhenius, Svante August

(Encyclopedia)Arrhenius, Svante August sfänˈtə, ärāˈnēəs [key], 1859–1927, Swedish chemist. He was a professor of physics in Stockholm in 1895 and became director of the Nobel Institute for Physical Chemi...