Back to Elements
    O

    Oxygen

    Nonmetal

    Atomic Number: 8 • Atomic Mass: 15.9990 u • Period: 2 • Group: 16

    Electron Configuration: 1s² 2s² 2p⁴
    Phase: Gas
    Electronegativity: 3.44
    Nitrogen (N)Fluorine (F)
    OverviewPropertiesAtomic StructureOccurrenceApplicationsHistory

    Overview

    Oxygen is the chemical element with the symbol O and atomic number 8. It belongs to the Nonmetal group and is located in period 2 of the periodic table. It exists as a gas under standard conditions.

    Basic Information

    • Symbol:O
    • Atomic Number:8
    • Atomic Mass:15.9990 u
    • Group:16
    • Period:2
    • Category:Nonmetal
    • Phase at STP:Gas
    • Electronegativity:3.44 (Pauling scale)

    Key Facts

    Fun Fact #1

    Makes up 21% of Earth's atmosphere

    Fun Fact #2

    Essential for cellular respiration

    Common Uses

    • Medical applications
    • Combustion
    • Steel production