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Edison, Thomas Alva

(Encyclopedia)Edison, Thomas Alva, 1847–1931, American inventor, b. Milan, Ohio. A genius in the practical application of scientific principles, Edison was one of the greatest and most productive inventors of his...

rutherfordium

(Encyclopedia)rutherfordium rŭᵺˌərfôrˈdēəm [key], artificially produced radioactive chemical element; symbol Rf; at. no. 104; mass number of most stable isotope 265; m.p., b.p., and sp. gr. unknown; valenc...

smog

(Encyclopedia)smog smŏg [key] [smoke+fog], dense, visible air pollution. Smog is commonly of two types. The gray smog of older industrial cities like London and New York derives from the massive combustion of coal...

nitric oxide

(Encyclopedia)nitric oxide or nitrogen monoxide, a colorless gas formed by the combustion of nitrogen and oxygen as given by the reaction: energy + N2 + O2 → 2NO; m.p. −163.6℃; b.p. −151.8℃. Nitric oxide ...

ammonia

(Encyclopedia)ammonia, chemical compound, NH3, colorless gas that is about one half as dense as air at ordinary temperatures and pressures. It has a characteristic pungent, penetrating odor. Ammonia forms a minute ...

arc, in electricity

(Encyclopedia)arc, in electricity, highly luminous and intensely hot discharge of electricity between two electrodes. The arc was discovered early in the 19th cent. by the English scientist Sir Humphry Davy, who so...

methanol

(Encyclopedia)methanol, methyl alcohol, or wood alcohol, CH3OH, a colorless, flammable liquid that is miscible with water in all proportions. Methanol is a monohydric alcohol. It melts at −97.8℃ and boils at 6...

Heck, Richard Fred

(Encyclopedia)Heck, Richard Fred, 1931–2015, American chemist, b. Springfield, Mass., Ph.D. Univ. of California, Los Angeles, 1954. Heck was a researcher at the Hercules Corporation in Wilmington, Del., from 1957...

electrode

(Encyclopedia)electrode, terminal through which electric current passes between metallic and nonmetallic parts of an electric circuit. In most familiar circuits current is carried by metallic conductors, but in som...

dry cleaning

(Encyclopedia)dry cleaning, process of cleaning fabrics without water. Special solvents and soaps are used so as not to harm fabrics and dyes that will not withstand the effects of ordinary soap and water. Dry clea...