|Group||Lanthanides||Melting point||1545°C, 2813°F, 1818 K|
|Period||6||Boiling point||1950°C, 3542°F, 2223 K|
|Block||f||Density (g cm−3)||9.32|
|Atomic number||69||Relative atomic mass||168.934|
|State at 20°C||Solid||Key isotopes||169Tm|
|Electron configuration||[Xe] 4f136s2||CAS number||7440-30-4|
|ChemSpider ID||22400||ChemSpider is a free chemical structure database|
- Thulium is a chemical element having an atomic number 69 with the symbol Tm, discovered by Theodor Cleve in the year 1879.
- It is the thirteenth element in the lanthanide series in the periodic table.
- The element is barely traced purely in nature but it is traced in minute amounts in minerals with other rare earth metals.
- It is used for laser manufacturing and for surgical purposes.
- Thulium is used as a source of radiation from portable X-ray devices and in nuclear reactions.
- Despite being slightly expensive, superconductors of high temperature use thulium.
- It is used for manufacturing ferrites, ceramic magnetic materials for microwave items.
- The element is the second least abundant element in the lanthanide series.
- It would tarnish once exposed to air due to its malleability and ductility.
- The element contains one natural isotope, 169Tm which has a half-life of 1.92 years.
- The remaining isotopes of the element have a half-life that ranges from 2 minutes to 64 hours.
- Natural thulium in ceramic magnetic materials is used in microwave equipment and are useful for doping fiber lasers.
- Once used for bombarding in a nuclear reactor, thulium could be employed as a radiation source in portable X-ray equipment.
- Unlike the other lanthanides, thulium has a low-to-moderate acute toxic rating.