SELENIUM

The selenium is a chemical element of the periodic table which symbol is and his atomic number is 34.
The selenium (of the Greek σελήνιον, radiance of the Moon) it was discovered in 1817 by Jöns Jacob Berzelius. On having visited the factory of Gripsholm's sulphuric acid it observed a dun reddish liquid that warmed to the blowpipe was detaching a stinking smell that was considered to be at the time typically and exclusive of the tellurium, in fact his name derives from his relation with this element since tellurium comes from the Latin Tellus, the Earth.
The selenium is very distributed in the terrestrial bark in the majority of the rocks and soils. It is possible to find in several allotropic forms.

Information obtained of www.wikipedia.org and www.lennetech.es