Astatine

See also:

Britannica Nobel Prize: Astatine - Overview and basic data.
ChemGlobe: Astatine - Electronic, thermal, and steric data, along with a table of isotopes.
Chemical Elements.com: Astatine - Basic information, atomic structure, and table of isotopes.
EnvironmentalChemistry.com: Astatine - Atomic structure, chemical and physical properties, and table of nuclides.
It's Elemental: Astatine - Basic physical and historical information.
LANL: Astatine - History, uses, production, and properties.
Lenntech: Astatine - Physical data, chemical properties, and health effects.
Visual Elements: Astatine - General and physical information, source, key isotopes, and ionisation energies.
WebElements: Astatine - Extensive information on history and properties.
Wikipedia: Astatine - Properties of the element, including its history, applications, and characteristics.
Radiochemistry of Astatine - Full text of the monograph by Evan H. Appelman (Argonne National Laboratory, Lemont, Illinois). [PDF] (March, 1960)