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    Tm

    Thulium

    Lanthanide

    Atomic Number: 69 • Atomic Mass: 168.9300 u • Period: 6 • Group: 101

    Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹³
    Phase: Solid
    Electronegativity: 1.25
    Erbium (Er)Ytterbium (Yb)
    OverviewPropertiesAtomic StructureOccurrenceApplicationsHistory

    Overview

    Thulium is the chemical element with the symbol Tm and atomic number 69. It belongs to the Lanthanide group and is located in period 6 of the periodic table. It exists as a solid under standard conditions.

    Basic Information

    • Symbol:Tm
    • Atomic Number:69
    • Atomic Mass:168.9300 u
    • Group:101
    • Period:6
    • Category:Lanthanide
    • Phase at STP:Solid
    • Electronegativity:1.25 (Pauling scale)

    Key Facts

    Fun Fact #1

    Named after Thule, mythical northern land

    Fun Fact #2

    Least abundant naturally occurring lanthanide

    Common Uses

    • Portable X-ray machines
    • Lasers
    • Ceramic magnetic materials