Columbia Encyclopedia

Search results

302 results found

battery, electric

(Encyclopedia)CE5 Lead storage cell: At the lead-dioxide electrode, electrons from the circuit combine with lead dioxide and sulfuric acid to form lead sulfate and water. At the spongy-lead electrode, lead react...

coenzyme

(Encyclopedia)coenzyme kō-ĕnˈzīm [key], any one of a group of relatively small organic molecules required for the catalytic function of certain enzymes. A coenzyme may either be attached by covalent bonds to a ...

hydrogen

(Encyclopedia)hydrogen hīˈdrəjən [key] [Gr.,=water forming], gaseous chemical element; symbol H; at. no. 1; interval in which at. wt. ranges 1.00784–1.00811; m.p. −259.14℃; b.p. −252.87℃; density 0.08...

airplane

(Encyclopedia)CE5 A. Side view of jet-propelled airplane B. Top view airplane, aeroplane, or aircraft, heavier-than-air vehicle, mechanically driven and fitted with fixed wings that support it in flight thro...

sulfuric acid

(Encyclopedia)sulfuric acid, chemical compound, H2SO4, colorless, odorless, extremely corrosive, oily liquid. It is sometimes called oil of vitriol. Although sulfuric acid is now one of the most widely used c...

mystery

(Encyclopedia)mystery or mystery story, literary genre in which the cause (or causes) of a mysterious happening, often a crime, is gradually revealed by the hero or heroine; this is accomplished through a mixture o...

Napoleon III

(Encyclopedia)Napoleon III (Louis Napoleon Bonaparte), 1808–73, emperor of the French (1852–70), son of Louis Bonaparte (see under Bonaparte, family), king of Holland. Napoleon III was a complex figure. H...

architecture

(Encyclopedia)architecture, the art of building in which human requirements and construction materials are related so as to furnish practical use as well as an aesthetic solution, thus differing from the pure utili...

light

(Encyclopedia)light, visible electromagnetic radiation. Of the entire electromagnetic spectrum, the human eye is sensitive to only a tiny part, the part that is called light. The wavelengths of visible light range ...

power, electric

(Encyclopedia)power, electric, energy dissipated in an electrical or electronic circuit or device per unit of time. The electrical energy supplied by a current to an appliance enables it to do work or provide some ...