Columbia Encyclopedia

Search results

500 results found

resistance, in electricity

(Encyclopedia)resistance, property of an electric conductor by which it opposes a flow of electricity and dissipates electrical energy away from the circuit, usually as heat. Optimum resistance is provided by a con...

resonance, in acoustics

(Encyclopedia)resonance, in acoustics: see vibration. ...

resonance, in chemistry

(Encyclopedia)resonance, in chemistry: see chemical bond. ...

restoration, in art

(Encyclopedia)restoration, in art: see art conservation and restoration. ...

Queenborough-in-Sheppey

(Encyclopedia)Queenborough-in-Sheppey, town (1991 pop. 33,362), on the Isle of Sheppey, Kent, SE England, at the confluence of the Medway and Thames rivers. Radios, furniture, glass, rubber products, and clothing a...

radical, in chemistry

(Encyclopedia)radical, in chemistry, group of atoms that are joined together in some particular spatial structure and that take part in most chemical reactions as a single unit. Important inorganic radicals include...

radical, in mathematics

(Encyclopedia)radical, in mathematics, symbol () placed over a number or expression, called the radicand, to indicate a root of the radicand. When used without a sign or index number, as in 4, it designates the pos...

ray, in zoology

(Encyclopedia)ray, extremely flat-bodied cartilaginous marine fish, related to the shark. The pectoral fins of most rays are developed into broad, flat, winglike appendages, attached all along the sides of the head...

ray, in physics

(Encyclopedia)ray, in physics, term denoting the straight line along which light or other form of radiation is propagated from its source. It generally refers to the line of propagation of waves but is also applied...

realism, in art

(Encyclopedia)realism, in art, the movement of the mid-19th cent. formed in reaction against the severely academic production of the French school. Realist painters sought to portray what they saw without idealizin...