Arsenic is a chemical element that has the symbol As and atomic number 33. Its Atomic Mass is 74.92. Its Ionic Charge is (3-). This is a notoriously poisonous metalloid that has many allotropic forms: yellow (molecular non-metallic) and several black and gray forms (metalloids) are a few that are seen. Three metalloidal forms of arsenic with different crystal structures are found free in nature (the minerals arsenic sensu strictu and the much rarer arsenolamprite and pararsenolamprite), but it is more commonly found as arsenide and arsenate compounds. Several hundred such mineral species are known. Arsenic and its compounds are used as pesticides, herbicides, insecticides and various alloys.

The most common oxidation states for arsenic are -3 (arsenides: usually alloy-like intermetallic compounds), +3 (arsenates(III) or arsenites, and most organoarsenic compounds), and +5 (arsenates(V): the most stable inorganic arsenic oxycompounds). Arsenic also bonds readily to itself, forming, for instance, As-As pairs in the red sulfide realgar and square As43- ions in the arsenide skutterudite. In the +3 oxidation state, the stereochemistry of arsenic is affected by possession of a lone pair of electrons.

The term "arsenic" was found in the following pages:

Conflict raised in chicken arsenic debate | EVISA's News
2004 Winter Conference on Plasma Spectroscopy | EVISA's Agenda of Events
Link database: FDA: Elemental Analysis Manual: Section 4.11: Arsenic Speciation in Rice and Rice Products Using High Performance Liquid Chromatography-Inductively Coupled Plasma-Mass Spectrometric Determination
Material database: RECIPE Chemicals + Instruments GmbH - ClinCal 9982 Serum calibrator lyophilised for trace elements: LOT 538
Link database: Blacksmith Institute: Arsenic in Groundwater - Arsenic Pollution
Arsenolipids in Fish Oil | EVISA's News
Two new Thio-Arsenosugars found in Scallops | EVISA's News
Directory of scientists: Marie Vahter
Material database: Food Analysis Performance Assessment Scheme (FAPAS) - Test Material T07101 (Soft Drink)
Material database: RECIPE Chemicals + Instruments GmbH - ClinChek 8883 Control blood plasma, lyophilised, trace elements level I: LOT 129
Arsenic species in rice: A new Australian reference material | EVISA's News
Susceptibility to arsenic toxicity influenced by genes | EVISA's News
Instrument database: TraceDetect - ArsenicGuard™ Online Arsenic Analyzer
Link database: CBI: The Netherlands legislation: Wood preserved with arsenic and chromium
New insights on arsenic cycling | EVISA's News
Material database: Strem Chemicals, Inc. - Dimethylarsinic acid (Cacodylic acid)
Material database: National Analysis Center for Iron & Steel (NACIS) - NCS ZC73012 - Trace Elements in Cabbage (NIM-GBW10014)
Plant uptake of trimethylantimony from contaminated soils | EVISA's News
Link database: CBI: Norway legislation: Wood preserved with arsenic and chromium
Accurate determination of arsenic and its species by internal standardization for quantification by ICP-MS | EVISA's News