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    Lr

    Lawrencium

    Actinide

    Atomic Number: 103 • Atomic Mass: 266.0000 u • Period: 7 • Group: 103

    Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f¹⁴ 7p¹
    Phase: Solid
    Electronegativity: 1.3
    Nobelium (No)Rutherfordium (Rf)
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    Physical & Chemical Properties

    Physical Properties

    • •Presumed to be metallic
    • •Highly radioactive
    • •Properties largely predicted from periodic trends
    Melting Point

    1900 K (1626.85 °C, 2960.33 °F)

    Boiling Point

    1900.15 K (1627.00 °C, 2960.60 °F)

    Density

    15.6 g/cm³

    Electronegativity

    1.3 (Pauling scale)

    Chemical Properties

    • •Forms +3 oxidation state
    • •Likely similar to lutetium chemically
    • •First actinide to have an electron in p orbital

    Electron Configuration

    1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f¹⁴ 7p¹

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