Back to Elements
    Pm

    Promethium

    Lanthanide

    Atomic Number: 61 • Atomic Mass: 145.0000 u • Period: 6 • Group: 101

    Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f⁵
    Phase: Solid
    Electronegativity: 1.13
    Neodymium (Nd)Samarium (Sm)
    OverviewPropertiesAtomic StructureOccurrenceApplicationsHistory

    Physical & Chemical Properties

    Physical Properties

    • •Silvery-white metal
    • •Radioactive
    • •Emits beta particles
    Melting Point

    1315 K (1041.85 °C, 1907.33 °F)

    Boiling Point

    3273 K (2999.85 °C, 5431.73 °F)

    Density

    7.26 g/cm³

    Electronegativity

    1.13 (Pauling scale)

    Chemical Properties

    • •Forms trivalent ions
    • •Similar to other lanthanides
    • •Radioactive decay

    Electron Configuration

    1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f⁵

    Electron configuration describes how electrons are distributed in atomic orbitals, showing how they are arranged in energy levels and subshells.