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    Th

    Thorium

    Actinide

    Atomic Number: 90 • Atomic Mass: 232.0400 u • Period: 7 • Group: 102

    Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 6d²
    Phase: Solid
    Electronegativity: 1.3
    Actinium (Ac)Protactinium (Pa)
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    Physical & Chemical Properties

    Physical Properties

    • •Silvery-white metal
    • •Soft and malleable
    • •High melting point
    Melting Point

    2115 K (1841.85 °C, 3347.33 °F)

    Boiling Point

    5061 K (4787.85 °C, 8650.13 °F)

    Density

    11.724 g/cm³

    Electronegativity

    1.3 (Pauling scale)

    Chemical Properties

    • •Forms primarily Th⁴⁺ ions
    • •Reacts slowly with water
    • •Slightly radioactive

    Electron Configuration

    1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 6d²

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