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formula, in chemistry

(Encyclopedia)formula, in chemistry, an expression showing the chemical composition of a compound. Formulas of compounds are used in writing the equations (see chemical equations) that represent chemical reactions....

ether, in chemistry

(Encyclopedia)CE5 Ethers ether, any of a number of organic compounds whose molecules contain two hydrocarbon groups joined by single bonds to an oxygen atom. The most common of these compounds is ethyl ether, C...

valence, in chemistry

(Encyclopedia)valence, combining capacity of an atom expressed as the number of single bonds the atom can form or the number of electrons an element gives up or accepts when reacting to form a compound. Atoms are c...

ion, in chemistry

(Encyclopedia)ion, atom or group of atoms having a net electric charge. Ionization has many applications. Vapor lamps and fluorescent lamps take advantage of the light given off when positive ions recombine with ...

emanation, in chemistry

(Encyclopedia)emanation: see radon.

sublimation, in chemistry

(Encyclopedia)sublimation sŭblĭmāˈshən [key], change of a solid substance directly to a vapor without first passing through the liquid state. The term is also used to describe the reverse process of the gas ch...

sleet

(Encyclopedia)sleet, precipitation of small, partially melted grains of ice. As raindrops fall from clouds, they pass through layers of air at different temperatures. If they pass through a layer with a temperature...

mixture

(Encyclopedia)mixture, in chemistry, a physical combination of two or more pure substances (i.e., elements or compounds). A mixture is distinguished from a compound, which is formed by the chemical combination of t...

powder

(Encyclopedia)powder, any mass of fine particles or dust prepared by various mechanical means, e.g., grinding of solid substances, or by chemical means, e.g., precipitation from solutions. In a special sense, the w...

Svedberg, Theodor

(Encyclopedia)Svedberg, Theodor or The tāˈōdôr svādˈbĕryə, tā [key], 1884–1971, Swedish chemist. He was professor of physical chemistry from 1912 to 1949 at the Univ. of Uppsala. For his fundamental rese...