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

    Occurrence

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

    • Earth's crust (30 parts per million)
    • Monazite sand
    • Bastnäsite mineral