Bismuth

WebElements: Calcium WebElements: Calcium- Extensive information on history, uses, occurrence, compounds, and properties of the element. Wikipedia: Calcium Wikipedia: Calcium- Properties of the element, including its history, applications, and characteristics. EnvironmentalChemistry.com: Calcium EnvironmentalChemistry.com: Calcium- Atomic structure, chemical and physical properties, and table of nuclides. ChemicalElements.com: Calcium ChemicalElements.com: Calcium- Basic information, atomic structure, and isotopes. It's Elemental: Calcium It's Elemental: Calcium- Basic physical and historical information.