selenium

se·le·ni·um  (s-ln-m)

n. Symbol Se

A nonmetallic element, red in powder form, black in vitreous form, and metallic gray in crystalline form, resembling sulfur and obtained primarily 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 (of gray selenium) 217°C; boiling point (gray) 684.9°C; specific gravity (gray) 4.79; (vitreous) 4.28; valence 2, 4, or 6. See Table at element.

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[Greek seln, moon (from selas, light, brightness) + -ium.]

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selenium [sɪˈliːnɪəm]

n

(Chemistry / Elements & Compounds) a nonmetallic element that exists in several allotropic forms. It occurs free in volcanic areas and in sulphide ores, esp pyrite. The common form is a grey crystalline solid that is photoconductive, photovoltaic, and semiconducting: used in photocells, solar cells, and in xerography. Symbol: Se; atomic no.: 34; atomic wt.: 78.96; valency: -2, 4, or 6; relative density: 4.79 (grey); melting pt.: 221°C (grey); boiling pt.: 685°C (grey)

[from New Latin, from Greek selēnē moon; named by analogy to tellurium (from Latin tellus earth)]

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selenium  (s-ln-m)

Symbol Se

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. See Periodic Table.

Thesaurus

Noun

1.

selenium - a toxic nonmetallic element related to sulfur and tellurium; occurs in several allotropic forms; a stable grey metallike allotrope conducts electricity better in the light than in the dark and is used in photocells; occurs in sulfide ores (as pyrite) atomic number 34, Se chemical element, element - any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter fool's gold, iron pyrite, pyrite - a common mineral (iron disulfide) that has a pale yellow color antioxidant - substance that inhibits oxidation or inhibits reactions promoted by oxygen or peroxides

Translations

selenium [sɪˈliːnɪəm] N → selenio m

selenium

n → Selen nt