Thulium

Thulium was discovered in 1879 by the Swedish chemist Per Teodor Cleve. Cleve isolated the element from a sample of ytterbite, a mineral containing several rare earth elements, through a process of fractional crystallization. He named the element after Thule, a term used in classical literature to describe a distant northern land, which reflects the origins of the rare earth minerals found in Scandinavia. Although thulium is not as well known as some of its lanthanide relatives, it played a crucial role in the development of rare earth chemistry. Its discovery contributed to the understanding of the lanthanide series and how these elements behave chemically and physically.

Thulium is relatively rare in the Earth's crust, with an abundance estimated at about 0.5 parts per million. It is typically found in minerals such as monazite and xenotime, along with other rare earth elements. Thulium can be extracted from these minerals through chemical processes involving ion exchange and solvent extraction. Notably, thulium does not occur in significant quantities in the Earth's surface compared to other elements, which is why it is classified as a rare earth element. The element is primarily mined in China, which produces a significant portion of the world's supply of rare earths.

Thulium does not have a known essential biological role in living organisms. However, studies have indicated that certain lanthanides, including thulium, may exhibit low levels of toxicity and could potentially impact enzyme activity or cellular processes if ingested in large quantities. Its compounds and oxides have been researched for possible biological applications, particularly in the fields of medical imaging and therapeutic techniques. As research continues, the potential interactions of thulium with biological systems may reveal new insights into its biological relevance.

Thulium is a relatively soft metal, ranking 3 on the Mohs hardness scale. It has a melting point of approximately 1,545 °C and a boiling point of 1,545 °C as well. Thulium is known for its strong magnetic properties, making it a material of interest in various electronic applications. Chemically, thulium exhibits oxidation states of +3 and +2, with the +3 state being the more stable. Thulium reacts with oxygen and moisture in the air, forming a layer of oxide that protects the metal from further oxidation. The element is also soluble in acids such as hydrochloric acid, forming thulium salts.

Thulium has a variety of applications, primarily due to its unique properties. One of its most notable uses is in portable medical and veterinary lasers, particularly for soft tissue surgery, due to its ability to generate specific wavelengths of light that can be absorbed efficiently by biological tissues. Additionally, thulium is used in solid-state lasers and is a key component in the production of high-temperature superconductors. The element's compounds are also employed in phosphors for color television tubes and in ceramics to enhance resistance and durability. Furthermore, thulium-doped materials have potential applications in telecommunications and nuclear reactors, showcasing its importance in various scientific and industrial fields.

• Thulium is the only lanthanide that is safe to handle in a powder form due to its low toxicity.
• The isotope thulium-169 is the most stable and is used in radiation therapy for cancer treatment.
• Thulium is utilized in the production of high-powered, high-efficiency lasers due to its ability to absorb and emit light effectively.