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    Ar

    Argon

    Noble Gas

    Atomic Number: 18 • Atomic Mass: 39.9480 u • Period: 3 • Group: 18

    Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶
    Phase: Gas
    Electronegativity: 0
    Chlorine (Cl)Potassium (K)
    OverviewPropertiesAtomic StructureOccurrenceApplicationsHistory

    Occurrence

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

    • Most abundant noble gas in Earth's atmosphere (0.934%)
    • Third most abundant gas in the atmosphere after nitrogen and oxygen
    • Small amounts dissolved in water
    • Present in some rocks and minerals from radioactive potassium decay