ChemicalElements.com: Barium (Popularity: )

Basic information, atomic structure, and isotopes.

Lenntech: Barium (Popularity: )

Physical data, chemical properties, health and environmental effects.

EnvironmentalChemistry.com: Barium (Popularity: )

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

WebElements: Barium (Popularity: )

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

Visual Elements: Barium (Popularity: )

Image, appearance, source, uses, key isotopes, and ionisation energies.

Wikipedia: Barium (Popularity: )

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

It's Elemental: Barium (Popularity: )

Basic physical and historical information.