Thulium (Tm) – Periodic Table [Element Information & More]

Thulium element (Tm) is in period 6 of a periodic table. Thulium is in the f-block and it is classified as a lanthanide on the periodic table.

There is a lot more information related to thulium which is mentioned in the Information Table given below.

So let’s dive right into it!

Table of contents

• Thulium element (Information Table)
• Thulium element in Periodic table
• Facts about Thulium
• Properties of Thulium
• Uses of Thulium

Thulium Element (Information Table)

The important data related to thulium element is given in the table below.

Appearance of thulium	Silvery white metallic appearance
Atomic number of thulium	69
Symbol of thulium	Tm
Atomic mass of thulium	168.93 u
Protons, Neutrons & Electrons in thulium	Protons: 69, Neutrons: 100, Electrons: 69
State of thulium (at STP)	Solid
Period number of thulium in periodic table	6
Block of thulium in periodic table	f-block
Category of thulium	Inner transition metals
Bohr model or Electrons per shell or Electrons arrangement in thulium	2, 8, 18, 31, 8, 2
Electron configuration of thulium	[Xe] 4f13 6s2
Orbital diagram of thulium
Electronegativity of thulium (on pauling scale)	1.25
Atomic radius of thulium (van der Waals radius)	227 picometers
Density of thulium	9.32 g/cm3
1st ionization energy of thulium	6.184 eV
Main isotope of thulium	169Tm
Melting point of thulium	1818 K or 1545 °C or 2813 °F
Boiling point of thulium	2223 K or 1950 °C or 3542 °F
Crystal structure of thulium	Hexagonal Close Packed (HCP)
Discovery of thulium	By Per Teodor Cleve in 1803

Also see: Interactive Periodic Table (It has rotating bohr models as well as many other details of all the 118 elements in a single periodic table).

Thulium element in Periodic table

The Thulium element (Tm) has the atomic number 69 and is located in period 6. Thulium is a metal and it is classified as a lanthanide group element.

Click on above elements in the periodic table to see their information.

Facts about thulium

Here are a few interesting facts about thulium element.

1. Per Teodor Cleve discovered thulium in the year 1879.
2. Thulium was given its name from the region “Thule”. This is the earliest name of Scandinavia (which is a region in North Europe).
3. Thulium is only 0.5 ppm by weight in the earth’s crust.
4. Thulium is the rarest of the rare earth metals present on the periodic table.
5. Majority of thulium is obtained from the ores like monazite, gadolinite and xenotime.

Properties of thulium

Here is a list of some physical properties and chemical properties of thulium.

Physical properties of thulium

• Thulium metal has a silvery white appearance.
• Thulium is soft and it can even be cut with a knife.
• Thulium has a density of 9.32 g/cm³ and its atomic mass is 168.93 amu.
• The melting point and boiling point of thulium is 1818 K and 2223 K respectively.

Chemical properties of thulium

• Thulium tarnishes easily when it is kept open in the air.
• Thulium also reacts with water and forms hydroxide. During this reaction, it liberates hydrogen gas.
• Thulium is reactive metal and because of this it is always found with other compounds from the earth’s crust.
• Thulium is present as a Tm³⁺ ion in its compounds.

Uses of thulium

Here are some uses of the thulium element.

• Thulium is used as an alloying metal with other metals to get the improved properties.
• Thulium is used for doping the fiber lasers.
• Thulium is also used in eurocurrency notes to detect the fake notes.

External resources:

1. Atomic Weight of Thulium | Commission on Isotopic Abundances and Atomic Weights. (n.d.). Atomic Weight of Thulium | Commission on Isotopic Abundances and Atomic Weights. https://ciaaw.org/thulium.htm
2. Atomic Data for Thulium (Tm). (n.d.). Atomic Data for Thulium (Tm). https://physics.nist.gov/PhysRefData/Handbook/Tables/thuliumtable1.htm
3. Thulium | Tm | ChemSpider. (n.d.). Thulium | Tm | ChemSpider. http://www.chemspider.com/Chemical-Structure.22400.html?rid=5090ea24-e9ca-4faa-a074-e26b0d53340f&page_num=0
4. P. (n.d.). Thulium | Tm (Element) – PubChem. Thulium | Tm (Element) – PubChem. https://pubchem.ncbi.nlm.nih.gov/element/Thulium
5. It’s Elemental – The Element Thulium. (n.d.). It’s Elemental – the Element Thulium. https://education.jlab.org/itselemental/ele069.html
6. Thulium – Wikipedia. (2009, June 6). Thulium – Wikipedia. https://en.wikipedia.org/wiki/Thulium
7. Prohaska, T., et al. (2022, May 1). Standard atomic weights of the elements 2021 (IUPAC Technical Report). Pure and Applied Chemistry, 94(5), 573–600. https://doi.org/10.1515/pac-2019-0603
8. Haynes, W. M. (Ed.). (2014, June 4). CRC Handbook of Chemistry and Physics. https://doi.org/10.1201/b17118
9. Kaye, G W.C., & Laby, T H. Tables of physical and chemical constants. 15th Edition. United States.
10. Sansonetti, J. E., & Martin, W. C. (2005, December). Handbook of Basic Atomic Spectroscopic Data. Journal of Physical and Chemical Reference Data, 34(4), 1559–2259. https://doi.org/10.1063/1.1800011
11. Bondi, A. (1964, March). van der Waals Volumes and Radii. The Journal of Physical Chemistry, 68(3), 441–451. https://doi.org/10.1021/j100785a001
12. Holden, et al. (2018, December 1). IUPAC Periodic Table of the Elements and Isotopes (IPTEI) for the Education Community (IUPAC Technical Report). Pure and Applied Chemistry, 90(12), 1833–2092. https://doi.org/10.1515/pac-2015-0703
13. Zhang, et al. (2011, January 11). Corrected Values for Boiling Points and Enthalpies of Vaporization of Elements in Handbooks. Journal of Chemical & Engineering Data, 56(2), 328–337. https://doi.org/10.1021/je1011086
14. Thulium – Element information, properties and uses | Periodic Table. (n.d.). Thulium – Element Information, Properties and Uses | Periodic Table. https://www.rsc.org/periodic-table/element/69/thulium
15. C&EN: IT’S ELEMENTAL: THE PERIODIC TABLE – THE LANTHANIDES. (n.d.). C&EN: IT’S ELEMENTAL: THE PERIODIC TABLE – THE LANTHANIDES. https://pubsapp.acs.org/cen/80th/lanthanides.html?