See also:

• Science: Chemistry: Elements: Lanthanides  (2)

ChemGlobe: Promethium - - Electronic, thermal, and steric data along with an isotope table.

ChemicalElements.com: Promethium - - Basic information, atomic structure, and isotopes.

EnvironmentalChemistry.com: Promethium - - Atomic structure, chemical and physical properties, and table of nuclides.

It's Elemental: Promethium - - Basic physical and historical information.

LANL: Promethium - - History, sources, uses, and properties.

Lenntech: Promethium - - Physical data, chemical properties, health and environmental effects.

Visual Elements: Promethium - - Image, animation, source, uses, and ionisation energies.

WebElements: Promethium - - Extensive information on history, uses, occurrence, compounds, and properties.

Wikipedia: Promethium - - Properties of the element, including its history, applications, and characteristics.