Back to Elements
    Th

    Thorium

    Actinide

    Atomic Number: 90 • Atomic Mass: 232.0400 u • Period: 7 • Group: 102

    Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 6d²
    Phase: Solid
    Electronegativity: 1.3
    Actinium (Ac)Protactinium (Pa)
    OverviewPropertiesAtomic StructureOccurrenceApplicationsHistory

    Overview

    Thorium is the chemical element with the symbol Th and atomic number 90. It belongs to the Actinide group and is located in period 7 of the periodic table. It exists as a solid under standard conditions.

    Basic Information

    • Symbol:Th
    • Atomic Number:90
    • Atomic Mass:232.0400 u
    • Group:102
    • Period:7
    • Category:Actinide
    • Phase at STP:Solid
    • Electronegativity:1.3 (Pauling scale)

    Key Facts

    Fun Fact #1

    Named after Thor, Norse god

    Fun Fact #2

    Can be used as nuclear fuel alternative to uranium

    Common Uses

    • Nuclear fuel
    • Gas mantles
    • Heat-resistant ceramics