Basic information, atomic structure, and isotopes.

Atomic structure, chemical and physical properties, and table of nuclides.

Basic physical and historical information.

Sources, uses, properties, and isotopes.

Physical data, chemical properties, and health effects.

Data tables and historic information.

Full text of the monograph by William T. Mullins and G. W. Leddicotte (Oak Ridge National Laboratory, Oak Ridge, Tennessee). [PDF]

Image, animation, source, uses, physical information, and key isotopes.

Extensive information on history, uses, occurrence, compounds, and properties of the element.

Properties of the element, including its history, applications, and characteristics.