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    Fr

    Francium

    Alkali Metal

    Atomic Number: 87 • Atomic Mass: 223.0000 u • Period: 7 • Group: 1

    Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s¹
    Phase: Solid
    Electronegativity: 0.7
    Radon (Rn)Radium (Ra)
    OverviewPropertiesAtomic StructureOccurrenceApplicationsHistory

    Occurrence

    Francium is found in various natural sources, including minerals, rocks, and the Earth's crust.

    • Extremely rare in nature
    • Trace amounts in uranium minerals
    • Produced in decay of actinium