Astatine
Links
Radiochemistry of Astatine
http://lib-www.lanl.gov/cgi-bin/getfile?rc000018.pdf
Full text of the monograph by Evan H. Appelman (Argonne National Laboratory, Lemont, Illinois). [PDF]
It's Elemental: Astatine
http://education.jlab.org/itselemental/ele085.html
Basic physical and historical information.
Chemical Elements.com: Astatine
http://www.chemicalelements.com/elements/at.html
Basic information, atomic structure, and table of isotopes.
Astatine
http://www.scescape.net/~woods/elements/astatine.html
Data tables and historic information.
Visual Elements: Astatine
http://www.chemsoc.org/viselements/pages/astatine.html
General and physical information, source, key isotopes, and ionisation energies.
Wikipedia: Astatine
http://www.wikipedia.org/wiki/Astatine
Properties of the element, including its history, applications, and charateristics.
EnvironmentalChemistry.com: Astatine
http://environmentalchemistry.com/yogi/periodic/At.html
Atomic structure, chemical and physical properties, and table of nuclides.
WebElements: Astatine
http://www.webelements.com/webelements/elements/text/At/key.html
Extensive information on history and properties.
Lenntech: Astatine
http://www.lenntech.com/Periodic-chart-elements/At-en.htm
Physical data, chemical properties, and health effects.