ChemGlobe: Palladium: Electronic, thermal, and steric data along with an isotope table.
ChemicalElements.com: Palladium: Basic information, atomic structure, and isotopes.
EnvironmentalChemistry.com: Palladium: Atomic structure, chemical and physical properties, and table of nuclides.
It's Elemental: Palladium: Basic physical and historical information.
LANL: Palladium: History, sources, properties, and uses.
Lenntech: Palladium: Physical data, chemical properties, health and environmental effects.
Palladium: Data tables and historic information.
Stillwater Palladium: All aspects of palladium with its extensive history, production, and uses.
Visual Elements: Palladium: Image, source, uses, physical information, and ionisation energies.
WebElements: Palladium: Extensive information on history, uses, occurrence, compounds, and properties.
Wikipedia: Palladium: Properties of the element, including its history, applications, and characteristics.