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    La

    Lanthanum

    Lanthanide

    Atomic Number: 57 • Atomic Mass: 138.9100 u • Period: 6 • Group: 3

    Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 5d¹
    Phase: Solid
    Electronegativity: 1.1
    Barium (Ba)Cerium (Ce)
    OverviewPropertiesAtomic StructureOccurrenceApplicationsHistory

    History

    Lanthanum has been known since ancient times

    Historical Timeline

    Extracted from cerium nitrate

    Initially confused with other rare earth elements