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Stark, Johannes

(Encyclopedia)Stark, Johannes, 1874–1957, German physicist, Ph.D. Univ. of Munich, 1897. From 1900 until he retired in 1922, Stark served short stints on the faculties of several academic institutions, including ...

Spectral Classes for Main Sequence Stars (table)

(Encyclopedia)Characteristics of Spectral Classes for Main Sequence Stars ...

spectroheliograph

(Encyclopedia)spectroheliograph, device for photographing the surface of the sun in a single wavelength of light, usually one corresponding to a chief element contained in the sun, e.g., hydrogen or calcium; the re...

zinc oxide

(Encyclopedia)zinc oxide, chemical compound, ZnO, that is nearly insoluble in water but soluble in acids or alkalies. It occurs as white hexagonal crystals or a white powder commonly known as zinc white. Zinc white...

Le Châtelier's principle

(Encyclopedia)Le Châtelier's principle, chemical principle that states that if a system in equilibrium is disturbed by changes in determining factors, such as temperature, pressure, and concentration of components...

barium

(Encyclopedia)barium bârˈēəm [key] [Gr.,=heavy], metallic chemical element; symbol Ba; at. no. 56; at. wt. 137.327; m.p. 725℃; b.p. 1,640℃; sp. gr. 3.5 at 20℃; valence +2. Barium is a soft, silver-white, ...

bubble chamber

(Encyclopedia)bubble chamber, device for detecting charged particles and other radiation by means of tracks of bubbles left in a chamber filled with liquid hydrogen or other liquefied gas. It was invented in 1952 b...

Morley, Edward Williams

(Encyclopedia)Morley, Edward Williams, 1838–1923, American scientist, b. Newark, N.J., grad. Williams College, 1860. From 1869 to 1906 he was professor of chemistry at Western Reserve College (now Case Western Re...

Jovian planets

(Encyclopedia)Jovian planets, the planets Jupiter, Saturn, Uranus, and Neptune. They are all larger and more massive than the earth. Since they rotate faster, they are more flattened at the poles than are the terre...

deodorizer

(Encyclopedia)deodorizer or deodorant, substance used to absorb or eliminate offensive odors. Disinfectants such as hydrogen peroxide, chlorine, and chlorine compounds eliminate odors caused by microorganisms. Adso...