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    I

    Iodine

    Halogen

    Atomic Number: 53 • Atomic Mass: 126.9000 u • Period: 5 • Group: 17

    Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁵
    Phase: Solid
    Electronegativity: 2.66
    Tellurium (Te)Xenon (Xe)
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    Occurrence

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

    • 60th most abundant element in Earth's crust (0.45 ppm)
    • Never found as free element in nature
    • Concentrated in seawater, seaweeds, and brine wells
    • Present in minerals such as caliche (sodium iodate)
    • Essential trace element for living organisms