It's Elemental: Technetium - Basic physical and historical information. ChemicalElements.com: Technetium - Basic information, atomic structure, and isotopes. EnvironmentalChemistry.com: Technetium - Atomic structure, chemical and physical properties, and table of nuclides. Wikipedia: Technetium - Properties of the element, including its history, applications, and characteristics. Radiochemistry of Technetium - Full text of the monograph by Edward Anders (Enrico Fermi Institute and Dept. of Chemistry, University of Chicago, Chicago, Illinois). WebElements: Technetium - Extensive information on history, uses, occurrence, compounds, and properties.