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    Tl

    Thallium

    Post Transition

    Atomic Number: 81 • Atomic Mass: 204.3800 u • Period: 6 • Group: 13

    Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p¹
    Phase: Solid
    Electronegativity: 1.62
    Mercury (Hg)Lead (Pb)
    OverviewPropertiesAtomic StructureOccurrenceApplicationsHistory

    Overview

    Thallium is the chemical element with the symbol Tl and atomic number 81. It belongs to the Post Transition group and is located in period 6 of the periodic table. It exists as a solid under standard conditions.

    Basic Information

    • Symbol:Tl
    • Atomic Number:81
    • Atomic Mass:204.3800 u
    • Group:13
    • Period:6
    • Category:Post Transition
    • Phase at STP:Solid
    • Electronegativity:1.62 (Pauling scale)

    Key Facts

    Fun Fact #1

    Name means 'green twig' in Greek

    Fun Fact #2

    Highly toxic

    Common Uses

    • Rat poison
    • Electronics
    • Medical imaging