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gram-atomic weight

(Encyclopedia)gram-atomic weight, amount of an atomic substance whose weight, in grams, is numerically equal to the atomic weight of that substance. For example, 1 gram-atomic weight of atomic oxygen, O (atomic wei...

Gerhardt, Charles Frédéric

(Encyclopedia)Gerhardt, Charles Frédéric shärl frādārēkˈ zhārärˈ [key], 1816–56, French chemist, b. Strasbourg. He revived the theory of acid radicals, which he called the theory of residues, and did va...

Chagai

(Encyclopedia)Chagai chäˈgī [key], town, W Pakistan, near the border with Afghanistan, on the trade route to Afghanistan and Iran. Pastoral Baluchi and Brahui inhabit the region, which is noted for its Oriental ...

carbon tetrachloride

(Encyclopedia)carbon tetrachloride tĕˌtrəklôrˌəmĕthˈān [key], CCl4, colorless, poisonous, liquid organic compound that boils at 76.8℃. It is toxic when absorbed through the skin or when inhaled. It react...

boron

(Encyclopedia)boron bōrˈŏn [key] [New Gr. from borax], chemical element; symbol B; at. no. 5; interval in which at. wt. ranges 10.806–10.821; m.p. about 2,300℃; sublimation point about 2,550℃; sp. gr. 2.3 ...

mimosa, in botany

(Encyclopedia)mimosa mĭmōˈsə [key], any tree, shrub, or herb of the genus Mimosa of the family Leguminosae (pulse family), chiefly tropical plants. They usually have feathery foliage and rounded clusters of fra...

mountain ash, in botany

(Encyclopedia)mountain ash, name for any species of the genus Sorbus of the family Rosaceae (rose family), hardy ornamental trees and shrubs native to the Northern Hemisphere, not related to the true ashes. They ar...

everlasting

(Encyclopedia)everlasting or immortelle ĭmˌôrtĕlˈ [key], names for numerous plants characterized by papery or chaffy flowers that retain their form and often their color when dried and are used for winter bouq...

drongo

(Encyclopedia)drongo drŏngˈgō [key], any of the insect-eating Old World birds of the family Dicruridae. Most species have black plumage with an iridescent purple or green shimmer and long, deeply forked tails. T...

freezing

(Encyclopedia)freezing, change of a substance from the liquid to the solid state. The temperature at which freezing occurs for a pure crystalline solid is called the freezing point and is a characteristic of the pa...