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    Cl

    Chlorine

    Halogen

    Atomic Number: 17 • Atomic Mass: 35.4500 u • Period: 3 • Group: 17

    Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁵
    Phase: Gas
    Electronegativity: 3.16
    Sulfur (S)Argon (Ar)
    OverviewPropertiesAtomic StructureOccurrenceApplicationsHistory

    Overview

    Chlorine is the chemical element with the symbol Cl and atomic number 17. It belongs to the Halogen group and is located in period 3 of the periodic table. It exists as a gas under standard conditions.

    Basic Information

    • Symbol:Cl
    • Atomic Number:17
    • Atomic Mass:35.4500 u
    • Group:17
    • Period:3
    • Category:Halogen
    • Phase at STP:Gas
    • Electronegativity:3.16 (Pauling scale)

    Key Facts

    Fun Fact #1

    Yellowish-green gas at room temperature

    Fun Fact #2

    Used as chemical weapon in World War I

    Common Uses

    • Water purification
    • Disinfectants
    • PVC production