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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)
    OverviewPropertiesAtomic StructureOccurrenceApplicationsHistory

    Overview

    Iodine is the chemical element with the symbol I and atomic number 53. It belongs to the Halogen group and is located in period 5 of the periodic table. It exists as a solid under standard conditions.

    Basic Information

    • Symbol:I
    • Atomic Number:53
    • Atomic Mass:126.9000 u
    • Group:17
    • Period:5
    • Category:Halogen
    • Phase at STP:Solid
    • Electronegativity:2.66 (Pauling scale)

    Key Facts

    Fun Fact #1

    Essential for thyroid function

    Fun Fact #2

    Produces violet vapor when heated

    Common Uses

    • Medical disinfectant
    • Photography
    • Table salt additive