It's Elemental: Arsenic - Basic physical and historical information. ChemicalElements.com: Arsenic - Basic information, atomic structure, and isotopes. USGS - Minerals Information: Arsenic - Overview and a number of publications in PDF format. EnvironmentalChemistry.com: Arsenic - Atomic structure, chemical and physical properties, and table of nuclides. Lenntech: Arsenic - Physical data, chemical properties, health and environmental effects. Wikipedia: Arsenic - Details the properties of the element, including its history, applications, and characteristics. Radiochemistry of Arsenic - Full text of the monograph by J. G. Cuninghame (Atomic Energy Research Establishment, Harwell, Didcot, Berkshire, England). WebElements: Arsenic - Extensive information on history, uses, occurrence, compounds, and properties of the element.