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The Element Thulium


"The Atom"

Definition of the Thulium Element
A bright, silvery rare-earth element and can be cut by a knife. It slowly tarnishes in air, but is more resistant to oxidation than most rare-earth elements. It also has some corrosion resistance in dry air and good ductility. It is obtained commercially from monazite, having an x-ray emitting isotope that is used in small portable medical x-ray units. The Atomic Number of this element is 69 and the Element Symbol is Tm.

Properties of the Thulium Element
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  

Periodic Table Group and Classification of the of the Thulium Element
Elements can be classified based on their physical states (States of Matter) e.g. gas, solid or liquid. This element is a solid. Thulium 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. Nearly 75% of all the elements in the Periodic Table are classified as metals which are detailed in the List of Metals.

Origin / Meaning of the name Thulium
Named after Thule, an ancient Roman name for a mythical country in the far north, possibly Scandinavia.

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

History of the Periodic Table
Check out the brief History of the Periodic Table which details dates and the names of famous scientists and chemists who contributed to the development of the Periodic Table.

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

Abundances of the element in different environments
% in Universe 110-8%
% in Sun 210-8%
% in Meteorites 2.910-6%
% in Earth's Crust 0.000045%
% in Oceans 210-11%
% in Humans N/A

Associated Uses of Thulium
Power for portable x-ray machines

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Rare Earth Elements
Atomic Number
Periodic Table

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