• WordNet 3.6
    • n 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)
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Webster's Revised Unabridged Dictionary
    • n Selenium (Chem) A nonmetallic element of the sulphur group of atomic number 34, analogous to sulphur in its compounds. It is found in small quantities with sulphur and some sulphur ores, and obtained in the free state as a dark reddish powder or crystalline mass, or as a dark metallic-looking substance. It exhibits under the action of light a remarkable variation in electric conductivity, and is used in certain electric apparatus. Symbol Se. Atomic weight 78.96.
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Century Dictionary and Cyclopedia
    • n selenium Chemical symbol, Se; atomic weight, 79.5. A non-metallic element extracted from the pyrite of Fahlun in Sweden, and discovered in 1818 by Berzelius. In its general chemical analogies it is related to sulphur and tellurium. It is found in combination with native tellurium, as in selen-tellurium, with sulphur in selen-sulphur; also in very small quantity in some of the varieties of iron pyrites, and in several rare selenides, as clausthalite, or lead selenide, etc. When precipitated it appears as a red powder, which melts when heated, and on cooling forms a brittle mass, nearly black, but transmitting red light when in thin plates. When heated in the air it takes fire, burns with a blue flame, and produces a gaseous compound, oxid of selenium, which has a most penetrating and characteristic odor of putrid horse-radish. Selenium undergoes a remarkable change in electrical resistance under the action of light: hence the use of selenium-cells. See resistance, 3, and photophone.
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Chambers's Twentieth Century Dictionary
    • n Selenium sē-lē′ni-um an element discovered by Berzelius in the refuse of a sulphuric-acid factory in 1817
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Webster's Revised Unabridged Dictionary
NL., from Gr. selh`nh the moon. So called because of its chemical analogy to tellurium,from L. tellus, the earth), being, as it were, a companion to it
Chambers's Twentieth Century Dictionary
Gr. sēlēne, the moon.


In literature:

I must try a different solution of selenium on the metal plate.
"Tom Swift and his Photo Telephone" by Victor Appleton
C. Contacts connected to insulated wires from selenium.
"Scientific American Supplement No. 275" by Various
My form of cell is a radical departure from all previous methods of employing selenium, in all of these respects.
"Scientific American Supplement, No. 492, June 6, 1885" by Various
The selenium then presents a grayish appearance, and is ready for use.
"Scientific American Supplement, No. 484, April 11, 1885" by Various
Selenium and tellurium behave similarly, but form crystalline solid fluorides.
"Scientific American Supplement, No. 832, December 12, 1891" by Various
When heated to redness in the air it becomes converted into silicon dioxide and free selenium.
"Scientific American Supplement, No. 841, February 13, 1892" by Various
Such substances are selenium, sulphur, arsenic, antimony, and tellurium.
"A System of Instruction in the Practical Use of the Blowpipe" by Anonymous
Selenium is thrown down at first of a fine brownish red, which gradually becomes darker.
"Scientific American Supplement, No. 441, June 14, 1884." by Various
Another pair of groups show the same tetrahedral form: magnesium, zinc and cadmium, positive; sulphur, selenium and tellurium, negative.
"Occult Chemistry" by Annie Besant and Charles W. Leadbeater
Selenium produces orange and red colors in glass.
"Artificial Light" by M. Luckiesh

In news:

Turkey is a notable source of selenium.
A deal that might have helped bankrupt Patriot Coal manage its huge liability for cleaning up selenium pollution from mountaintop removal mining operations has fallen through, federal court records have revealed.
Coping with two-headed fish and other effects of selenium .
Deformities in trout caused by selenium .
Scientific review blasts Simplot's selenium report IDAHO FALLS, Idaho — The J.R.
Alpha Natural Resources will have to clean up selenium pollution at three of the mountaintop removal mines it bought from Massey Energy, under a legal settlement with environmental groups announced Monday.
No Link Between Selenium , Lower Lung Cancer Risk.
Sauce Labs released Sauce Builder, a Web-application-testing tool based on Selenium .
Sauce Labs Delivers Selenium -based Sauce Builder.
Three environmental groups sued coal operator ICG Eastern in federal court Wednesday over a Webster County surface mine they say has been discharging toxic selenium into streams for years.
Selenium Doubles Up In Proteins.
The essential trace mineral, selenium , is of fundamental importance to human health.
A federal judge ruled Monday that Patriot Coal continues to violate water-quality limits on selenium, and scheduled a hearing for early August to consider steps to stop the company's delays in cleaning up the illegal pollution.
Coping with two-headed fish and other effects of selenium.
UMWA statement on selenium agreement between Patriot and environmental groups.

In science:

On the other hand, to our knowledge, the only experimental work assessing the two separate contributions to excess entropy has been made on a very simple material, elemental selenium .
Can experiments select the configurational component of excess entropy?
These results astonishingly agree with the value found for Sc /Sexc (0.69) in selenium , where the configurational entropy was calculated from neutron scattering data.
Can experiments select the configurational component of excess entropy?
Among other elements, these molecules contain sulfur or selenium atoms.
Route to Room-Temperature Superconductivity from a Practical Point of View
Villa, “Infrared refract ive indexes of silicon germanium and modified selenium glass, ” J.
Temperature dependent refractive index of silicon and germanium
Regarding the s-process elements, Sterling & Dinerstein (2008) found that the mean abundance of selenium and krypton in stars suspected of being binaries (though none of the stars in their list has been confirmed) is indeed smaller than for the average of other stars.
The Origin and Shaping of Planetary Nebulae: Putting the Binary Hypothesis to the Test