Columbia Encyclopedia

(Encyclopedia) Grignard reagent grēnyärdˈ rēāˈjənt [key], any of an important class of extremely reactive chemical compounds used in the synthesis of hydrocarbons, alcohols, carboxylic acids, and other compou...

(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...

(Encyclopedia) Hidalgo ēᵺälˈgō [key], state, 8,058 sq mi (20,870 sq km), central Mexico. Pachuca de Soto is the capital. Cross...

(Encyclopedia) gunpowder, explosive mixture; its most common formula, called “black powder,” is a combination of saltpeter, sulfur, and carbon in the form of charcoal. Historically, the relative amounts of the c...

(Encyclopedia) calcium oxide, chemical compound, CaO, a colorless, cubic crystalline or white amorphous substance. It is also called lime, quicklime, or caustic lime, but commercial lime often contains impurities, e...

(Encyclopedia) manganese măngˈgənēs, mănˈ– [key] [Lat.,=magnet], metallic chemical element; symbol Mn; at. no. 25; at. wt. 54.93805; m.p. about 1,244℃; b.p. about 1,962℃; sp. gr. 7.2 to 7.45, depending o...

(Encyclopedia) Narbonne närbônˈ [key], city (1990 pop. 47,086), Aude dept., S France, near the Mediterranean coast. It is the commercial center of a wine-growing region and an industrial city producing sulfur, co...

(Encyclopedia) club moss, name generally used for the living species of the class Lycopodiopsida, a primitive subdivision of vascular plants. The Lycopodiopsida were a dominant plant group in the Carboniferous perio...

(Encyclopedia) Helwan wänˈ [key], town (1989 est. pop. 230,000), N Egypt, on the Nile River, opposite the ruins of Memphis; a suburb of Cairo. Manufactures include iron and steel, cement, and textiles; there is a ...

(Encyclopedia) calcium hydroxide, Ca(OH)2, colorless crystal or white powder. It is prepared by reacting calcium oxide (lime) with water, a process called slaking, and is also known as hydrated lime or slaked lime. ...