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    He

    Helium

    Noble Gas

    Atomic Number: 2 • Atomic Mass: 4.0026 u • Period: 1 • Group: 18

    Electron Configuration: 1s²
    Phase: Gas
    Electronegativity: 0
    Hydrogen (H)Lithium (Li)
    OverviewPropertiesAtomic StructureOccurrenceApplicationsHistory

    Occurrence

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

    • Second most abundant element in the universe (23% by mass)
    • Created in stars through nuclear fusion
    • On Earth, found in natural gas deposits (up to 7%)
    • Produced by radioactive decay of elements like uranium and thorium