Back to Elements
    P

    Phosphorus

    Nonmetal

    Atomic Number: 15 • Atomic Mass: 30.9740 u • Period: 3 • Group: 15

    Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p³
    Phase: Solid
    Electronegativity: 2.19
    Silicon (Si)Sulfur (S)
    OverviewPropertiesAtomic StructureOccurrenceApplicationsHistory

    Physical & Chemical Properties

    Physical Properties

    • •Exists in several allotropes (white, red, black)
    • •White phosphorus glows in the dark (phosphorescence)
    • •Red phosphorus is amorphous, more stable than white
    • •Black phosphorus is the most thermodynamically stable form
    Melting Point

    317.3 K (44.15 °C, 111.47 °F)

    Boiling Point

    553.6 K (280.45 °C, 536.81 °F)

    Density

    1.82 g/cm³

    Electronegativity

    2.19 (Pauling scale)

    Chemical Properties

    • •White phosphorus is highly reactive and spontaneously flammable in air
    • •Forms oxides with various oxidation states (+3, +5)
    • •Essential component of biological molecules (DNA, RNA, ATP)
    • •Can form various acids (phosphoric acid most common)

    Electron Configuration

    1s² 2s² 2p⁶ 3s² 3p³

    Electron configuration describes how electrons are distributed in atomic orbitals, showing how they are arranged in energy levels and subshells.