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    Se

    Selenium

    Nonmetal

    Atomic Number: 34 • Atomic Mass: 78.9710 u • Period: 4 • Group: 16

    Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁴
    Phase: Solid
    Electronegativity: 2.55
    Arsenic (As)Bromine (Br)
    OverviewPropertiesAtomic StructureOccurrenceApplicationsHistory

    Overview

    Selenium is the chemical element with the symbol Se and atomic number 34. It belongs to the Nonmetal group and is located in period 4 of the periodic table. It exists as a solid under standard conditions.

    Basic Information

    • Symbol:Se
    • Atomic Number:34
    • Atomic Mass:78.9710 u
    • Group:16
    • Period:4
    • Category:Nonmetal
    • Phase at STP:Solid
    • Electronegativity:2.55 (Pauling scale)

    Key Facts

    Fun Fact #1

    Named after the moon

    Fun Fact #2

    Essential nutrient for humans

    Common Uses

    • Glass production
    • Photocopiers
    • Nutritional supplements