Arsenic Properties

Description

Arsenic is a metalloid. It occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. It was first documented by Albertus Magnus in 1250. The main use of metallic arsenic is for strengthening alloys of copper and especially lead. It is a common n-type dopant in semiconductor electronic devices, and the optoelectronic compound gallium arsenide is the most common semiconductor in use after doped silicon. Arsenic and its compounds, especially the trioxide, are used in the production of pesticides, herbicides, and insecticides. These applications are declining, however, as many of these compounds are being phased out. Arsenic poisoning from naturally occurring arsenic compounds in drinking water remains a problem in many parts of the world. During the 18th, 19th, and 20th centuries, a number of arsenic compounds have been used as medicines, including arsphenamine and arsenic trioxide. Arsphenamine as well as neosalvarsan was indicated for syphilis and trypanosomiasis, but has been superseded by modern antibiotics. Arsenic trioxide has been used in a variety of ways over the past 500 years, but most commonly in the treatment of cancer. Arsenic is also used in bronzing and pyrotechnics and for taxonomic sample preservation.