Back to Elements
    As

    Arsenic

    Metalloid

    Atomic Number: 33 • Atomic Mass: 74.9220 u • Period: 4 • Group: 15

    Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p³
    Phase: Solid
    Electronegativity: 2.18
    Germanium (Ge)Selenium (Se)
    OverviewPropertiesAtomic StructureOccurrenceApplicationsHistory

    History

    Arsenic has been known since ancient times

    Historical Timeline

    Compounds known since ancient times

    Element isolated by Albertus Magnus around 1250

    Used in both medicine and poisons throughout history