Selenium meaning

sĭ-lē'nē-əm
A nonmetallic element, red in powder form, black in vitreous form, and metallic gray in stable crystalline form, resembling sulfur and found as an impurity in pyrites or obtained as a byproduct of electrolytic copper refining. It is widely used in rectifiers, as a semiconductor, and in xerography. Its photovoltaic and photoconductive actions make it useful in photocells, photographic exposure meters, and solar cells. Atomic number 34; atomic weight 78.96; melting point (gray) 221°C; boiling point (gray) 685°C; specific gravity (gray) 4.79; (vitreous) 4.28; valence 2, 4, or 6.
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A nonmetallic chemical element with several allotropic forms, used in photoelectric devices because its electrical conductivity varies with the intensity of light: also used in rectifiers, in certain electrostatic copying processes, etc.: symbol, Se; at. no. 34
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A nonmetallic element that occurs in a gray crystalline form, as a red powder, or as a black glassy material. It is highly photosensitive and can be used to convert light into electricity. Its ability to conduct electricity also increases with higher exposure to light. For these reasons selenium is used in photocopying technology, photography, and solar cells. Atomic number 34; atomic weight 78.96; melting point 217°C; boiling point 684.9°C; specific gravity (gray) 4.79; (red) 4.5; (black) 4.28; valence 2, 4, or 6.
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A gray, non-metallic element, selenium is 34 on the periodic table of elements and has an atomic weight of 78.96. Selenium usually is obtained as a by-product of lead, copper, and nickel refining, and is used in photoelectric cells, TV cameras, light meters, copy machines, and anti-dandruff shampoos, as well as to color glass red and to give black and white silver prints greater image stability. Although toxic to humans in excess, selenium is considered to be an essential mineral in small amounts. See also photophone.
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A nonmetallic chemical element (symbol Se) with an atomic number of 34.
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Origin of selenium

  • Greek selēnē moon (from selas light, brightness) –ium
    From American Heritage Dictionary of the English Language, 5th Edition
  • A New Latin word derived by Swedish chemist Berzelius in 1818, from Ancient Greek Σελήνη (selēnē, "moon").
    From Wiktionary