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tellurium

(Encyclopedia)tellurium tĕlo͝orˈēəm [key] [Lat.,=earth], semimetallic chemical element; symbol Te; at. no. 52; at. wt. 127.60; m.p. 450℃; b.p. 990℃; sp. gr. 6.24 at 20℃; valence −2, +4, or +6. Telluriu...

methionine

(Encyclopedia)CE5 methionine mĕthīˈənēn [key], organic compound, one of the 20 amino acids commonly found in animal proteins. Only the L-stereoisomer appears in mammalian protein. It is one of the several e...

Khíos

(Encyclopedia)Khíos kīˈŏs [key], island (1991 pop. 51,060), c.350 sq mi (910 sq km), E Greece, in the Aegean Sea, just W of Asia Minor. It is mountainous and is famous for its scenic beauty and good climate. Th...

pollution allowance

(Encyclopedia)pollution allowance or emission rights, government-issued permit to emit a certain amount of a pollutant. The holder of the permit may use it to pollute legally, may trade permits, or may sell the per...

pyrite

(Encyclopedia)pyrite pīrīˈtēz, pə–, pīˈrīts [key], pale brass-yellow mineral, the bisulfide of iron, FeS2. It occurs most commonly in crystals (belonging to the isometric system and usually in the form of...

Paracelsus, Philippus Aureolus

(Encyclopedia)Paracelsus, Philippus Aureolus fĭlĭpˈəs ôrēōˈləs părəsĕlˈsəs [key], 1493?–1541, Swiss physician and alchemist. His original name Theophrastus Bombastus von Hohenheim. He traveled widel...

spraying

(Encyclopedia)spraying, horticultural practice of applying fungicides, insecticides, and herbicides, usually in solution, to plants. It may be accomplished by various means, e.g., the watering can, sprinkler attach...

copper, chemical element

(Encyclopedia)copper, metallic chemical element; symbol Cu [Lat. cuprum=copper]; at. no. 29; at. wt. 63.546; m.p. 1,083.4℃; b.p. 2,567℃; sp. gr. 8.96 at 20℃; valence +1 or +2. Copper and some of its alloys ha...

hafnium

(Encyclopedia)hafnium hăfˈnēəm [key], metallic chemical element; symbol Hf; at. no. 72; at. wt. 178.49; m.p. about 2,227℃; b.p. 4,602℃; sp. gr. 13.31 at 20℃; valence +4. Hafnium is a lustrous, ductile, si...

Guerrero

(Encyclopedia)Guerrero, state, 24,887 sq mi (64,457 sq km), S Mexico, on the Pacific Ocean. The capital is Chilpancingo. Dominated by the Sierra Madre del Sur, which ...