Facts about the Classification of the Element Thulium
Thulium is classified as an element in the Lanthanide series as one of the "Rare Earth Elements" which can located in Group 3 elements of the Periodic Table and in the 6th and 7th periods. The Rare Earth Elements are divided into the Lanthanide and Actinide series. The elements in the Lanthanide series closely resemble lanthanum, and one another, in their chemical and physical properties. Their compounds are used as catalysts in the production of petroleum and synthetic products.

Brief Facts about the Discovery and History of the Element Thulium
Thulium was discovered by Per Teodor Cleve in Sweden in 1879

Occurrence of the element Thulium
Found in small quantities in minerals with other rare earths - gadolinite, euxenite, xenotime

Common Uses of Thulium
Lasers
Power for portable x-ray machines

The Properties of the Element Thulium

Name of Element : Thulium
Symbol of Element : Tm
Atomic Number: 69
Atomic Mass: 168.9342 amu
Melting Point: 1545.0 °C - 1818.15 °K
Boiling Point: 1727.0 °C - 2000.15 °K
Number of Protons/Electrons: 69
Number of Neutrons: 100
Crystal Structure: Hexagonal
Density @ 293 K: 9.321 g/cm3
Color: silverish