Columbia Encyclopedia

Search results

437 results found

metal

(Encyclopedia)metal, chemical element displaying certain properties by which it is normally distinguished from a nonmetal, notably its metallic luster, the capacity to lose electrons and form a positive ion, and th...

fire fighting

(Encyclopedia)fire fighting, the use of strategy, personnel, and apparatus to extinguish, to confine, or to escape from fire. Ancient Rome is known to have had a fire department consisting by the 1st cent. of app...

fluorine

(Encyclopedia)fluorine flo͞oˈərēn, –rĭn [key], gaseous chemical element; symbol F; at. no. 9; at. wt. 18.9984; m.p. −219.6℃; b.p. −188.14℃; density 1.696 grams per liter at STP; valence −1. Fluorin...

food preservation

(Encyclopedia)food preservation, methods of preparing food so that it can be stored for future use. Because most foods remain edible for only a brief period of time, people since the earliest ages have experimented...

electric circuit

(Encyclopedia)CE5 A. Series circuit: Current is the same through each resistance; voltage divides in direct proportion to each resistance. B. Parallel circuit: Voltage drop is the same over each resistance; curr...

earth, in geology and astronomy

(Encyclopedia)CE5 A. Cross section of the earth, showing its shells B. Detailed cross section of the crust and upper mantle: The lithosphere consists of the hard rock in the crust and upper mantle, lying above t...

Miami, cities, United States

(Encyclopedia)Miami mīămˈē, –ə [key]. 1 City (1990 pop. 358,548), seat of Dade co., SE Fla., on Biscayne Bay at the mouth of the Miami River; inc. 1896. The region of Greater Miami encompasses all of Dade co...

sacrifice

(Encyclopedia)sacrifice [Lat. sacrificare=to make holy], a type of religious offering, or gift to a superior or supreme being, in which the offering is consecrated through its destruction. The Paleolithic evidenc...

explosive

(Encyclopedia)explosive, substance that undergoes decomposition or combustion with great rapidity, evolving much heat and producing a large volume of gas. The reaction products fill a much greater volume than that ...

electrolysis

(Encyclopedia)CE5 Electrolysis: In a typical reaction electrodes are placed in a solution of hydrogen chloride, HCl, which contains both hydrogen and chlorine ions. The battery removes electrons from the anode, ...