Basic information, atomic structure, and table of isotopes.

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

Data tables and historic information.

Basic physical and historical information.

History, sources, uses, properties, and isotopes.

Physical data, chemical properties, health and environmental effects.

Full text of the monograph by Jacob Kleinberg (University of California, Los Alamos Scientific Laboratory, Los Alamos, New Mexico and University of Kansas, Lawrence, Kansas). [PDF]

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

General and physical information, source, uses, biological role, key isotopes, and ionisation energies.

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

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