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selenium
(Encyclopedia)selenium səlēˈnēəm [key], nonmetallic chemical element; symbol Se; at. no. 34; at. wt. 78.96; m.p. 217℃; b.p. about 685℃; sp. gr. 4.81 at 20℃; valence −2, +4, or +6. Selenium is directly ...Periodic Table of the Elements: Selenium
(Encyclopedia)Periodic Table of the Elements: Selenium ...Se
(Encyclopedia)Se, symbol for the element selenium. ...Copperbelt
(Encyclopedia)Copperbelt, mining region, N central Zambia, central Africa. A natural extension of the mineral-rich region of SE Congo, the Copperbelt is one of the richest sources of copper in the world. Cobalt, se...dandruff
(Encyclopedia)dandruff, excessive flaking of skin from the scalp, apparent as dry or greasy diffuse scaling with variable itching. It is the sign of a skin disease, such as seborrhea or a fungal infection. Treatmen...poisonous plant
(Encyclopedia)poisonous plant, any plant possessing a property injurious to man or animal. Plants may be poisonous to the touch (e.g., poison ivy, poison sumac), or orally toxic (e.g., poison hemlock, deadly amanit...Berzelius, Jöns Jakob, Baron
(Encyclopedia)Berzelius, Jöns Jakob, Baron bərzēˈlēəs; Swed. yöns yäˈkôp bĕrsāˈlĭəs [key], 1779–1848, Swedish chemist, M.D. Univ. of Uppsala, 1802. He was noted for his work as teacher at the medic...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...nonmetal
(Encyclopedia)nonmetal, chemical element possessing certain properties by which it is distinguished from a metal. In general, this distinction is drawn on the basis that a nonmetal tends to accept electrons and for...antioxidant
(Encyclopedia)antioxidant, substance that prevents or slows the breakdown of another substance by oxygen. Synthetic and natural antioxidants are used to slow the deterioration of gasoline and rubber, and such antio...Browse by Subject
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