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Selenium (Se): Fun Facts and Information About the Element


What is the symbol? Se
What is the atomic number? 34
What is the atomic weight? 78.96
What is the melting point in Celsius? 217
What is the boiling point in Celsius? 685
What is the density (g/cm3)? 4.79
What year was it discovered? 1817
Who discovered the element? Jöns Jacob Berzelius
What group is the element in? 16
What is the electron configuration? [Ar] 3d10 4s2 4p4
What is the ionization energy? 9.7524
What element category is it in? Other Nonmetals

Where is Selenium Found?

Selenium is found in a few rare minerals such as crooksite and clausthalite. In years past it has been obtained from flue dusts remaining from processing copper sulfide ores, but the anode metal from electrolytic copper refineries now provide the source of most of the world’s selenium. Selenium is recovered by roasting the mud with soda or sulfuric acid, or by smelting them with soda and niter.

What is Selenium Used For?

Selenium is used in Xerography for reproducing and copying documents, letters, etc. It is used by the glass industry to decolorize glass and to make ruby-colored glasses and enamels. It is also used as a photographic toner, and as an additive to stainless steel.