R. Boyd
2011
Citations
4
Influential Citations
63
Citations
Journal
Nature chemistry
Abstract
Element 34 was discovered in 1817 by Jöns Jacob Berzelius, the ‘father of Swedish chemistry’. While preparing sulfuric acid he noticed a residue, which he first thought was tellurium. Realizing it was a new element, he decided to name it after the Greek word for Moon, selènè, in a similar manner to tellurium, named two decades earlier by Martin Heinrich Klaproth after the Latin word for Earth, tellus. In nature, selenium is rarely found in its elemental form and only occurs in a few minerals — for example in sulfide ores such as pyrite, where it partially replaces sulfur. It exists as six naturally occurring isotopes with mass numbers 74, 76, 77, 78, 80 and 82; 80Se and 78Se are the most common, with natural abundances close to 50 and 24%, respectively. Selenium is a semi-metallic element that belongs to the family of chalcogens (group 15). Placed just between sulfur and tellurium in that column of the periodic table, it resembles both elements in some aspects. In particular, it has similar allotropic forms and compounds to those of sulfur — for example, red selenium is a Se8 macrocycle similar to the sulfur allotrope S8.