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

    History

    Francium has been known since ancient times

    Historical Timeline

    Discovered as decay product of actinium

    Last naturally occurring element discovered