Basic information, atomic structure, and isotopes.

Basic properties, compounds, brief history, information about production processes.

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

Basic physical and historical information.

Basic information and history.

Physical data, chemical properties, health and environmental effects.

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

Data tables and historic information.

Statistics and information on the worldwide supply, demand, and flow of the element (PDF format).

Image, general and physical information, source, uses, key isotopes, and ionisation energies.

Extensive information on history, uses, occurrence, compounds, and properties.

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