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Thulium at Chemical Elements.com
Basic Information | Atomic Structure | Isotopes | Related Links | Citing This Page

Basic Information

Name: Thulium
Symbol: Tm
Atomic Number: 69
Atomic Mass: 168.9342 amu
Melting Point: 1545.0 °C (1818.15 K, 2813.0 °F)
Boiling Point: 1727.0 °C (2000.15 K, 3140.6 °F)
Number of Protons/Electrons: 69
Number of Neutrons: 100
Classification: Rare Earth
Crystal Structure: Hexagonal
Density @ 293 K: 9.321 g/cm3
Color: silverish

Atomic Structure

[Bohr Model of Thulium]  
Number of Energy Levels: 6

    First Energy Level: 2
    Second Energy Level: 8
    Third Energy Level: 18
    Fourth Energy Level: 31
    Fifth Energy Level: 8
    Sixth Energy Level: 2


Isotope Half Life
Tm-16893.1 days
Tm-170128.6 days
Tm-1711.92 years
Tm-1722.65 days


Date of Discovery: 1879
Discoverer: Per Theodor Cleve
Name Origin: From Thule (ancient name of Scandinavia)
Uses: power for portable x-ray machines
Obtained From: gadolinite, euxenite, xenotime

Related Links

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MLA Format for Citing This Page

Bentor, Yinon. Chemical Element.com - Thulium. <http://www.chemicalelements.com/elements/tm.html>.

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