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ore

(Encyclopedia)ore, metal-bearing mineral mass that can be profitably mined. Nearly all rock deposits contain some metallic minerals, but in many cases the concentration of metal is too low to justify mining the ore...

darmstadtium

(Encyclopedia)darmstadtium, artificially produced radioactive chemical element; symbol Ds; at. no. 110; mass number of most stable isotope 281; m.p., b.p., sp. gr., and valence unknown. Situated in Group 10 of the ...

meitnerium

(Encyclopedia)meitnerium mītnĭrˈēəm [key], artificially produced radioactive chemical element; symbol Mt; at. no. 109; mass number of most stable isotope 276; m.p., b.p., sp. gr., and valence unknown. Situated...

meristem

(Encyclopedia)meristem mĕrˈistĕmˌ [key], a specialized section of plant tissue characterized by cell division and growth. Much of the mature plant's growth is provided by meristems. Apical meristems found at th...

nobelium

(Encyclopedia)nobelium nōbēˈlēəm [key], artificially produced radioactive chemical element; symbol No; at. no. 102; mass no. of most stable isotope 259; m.p. 827℃; b.p. and density unknown; valence +2, +3. I...

Carol II

(Encyclopedia)Carol II, 1893–1953, king of Romania, son of King Ferdinand and Queen Marie. While crown prince, he contracted a morganatic marriage with Zizi Labrino but divorced her to marry (1921) Princess Helen...

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...

atmosphere

(Encyclopedia)CE5 Atmosphere atmosphere [Gr.,=sphere of air], the mixture of gases surrounding a celestial body with sufficient gravity to maintain it. Although some details about the atmospheres of other plane...

Andrée, Salomon August

(Encyclopedia)Andrée, Salomon August säˈlo͞omôn ouˈgəst ändrāˈ [key], 1854–97, Swedish polar explorer, grad. Royal Inst. of Technology, Stockholm. An aeronautical engineer and head of the Swedish patent...

Freon

(Encyclopedia)Freon frēˈŏn [key] [trade name], any one of a special class of chemical compounds that are used as refrigerants, aerosol propellants, and solvents. These compounds are haloalkanes, i.e., halogen de...