Chemical Elements.com - Plutonium (Pu)
Information on the chemical properties of plutonium, as well as its electron cloud diagram.
EnvironmentalChemistry.com: Plutonium
Atomic structure, chemical and physical properties, and table of nuclides.
Lenntech: Plutonium
Physical data, chemical properties, health and environmental effects.
Radiochemistry of Plutonium
Full text of the monograph by George H. Coleman (University of California, Lawrence Radiation Laboratory, Livermore, California). [PDF]
Superconductor: Plutonium
Describes the way that scientists found a way to use plutonium as a supercondutor.
Webelements : Plutonium
Gives extensive information concerning Plutonium, including its compounds, history, and properties.