At

    Astatine

    Halogen

    Atomic Number: 85 • Atomic Mass: 210.0000 u • Period: 6 • Group: 17

    Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁵
    Phase: Solid
    Electronegativity: 2.2

    Atomic Structure

    Electron Configuration

    1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁵

    The electron configuration represents the distribution of electrons in atomic orbitals, showing how they are arranged in energy levels and subshells.

    Subatomic Particles

    Protons

    85

    Positive charge

    Neutrons

    125

    No charge

    Electrons

    85

    Negative charge

    Atomic Number & Mass Number

    The atomic number (85) represents the number of protons in the nucleus.

    The mass number (210) is the sum of protons and neutrons in the nucleus.

    Isotopes

    Isotopes are variants of an element that have the same number of protons but different numbers of neutrons.

    At-210

    At-211

    Stability & Half-Life

    Half-Life Information

    At-210: 8.1 hours; At-211: 7.2 hours

    Half-life is the time required for half of the atoms of a radioactive isotope to decay.

    Periodic Table Location

    Period: 6

    Group: 17

    Category: Halogen

    The period indicates the main energy level, while the group suggests similar chemical properties.