Thulium was discovered by Per Theodore Cleve (Sweden) in 1879. Named after Thule, an ancient name for Scandinavia. It is soft, malleable, ductile, silvery metal. Tarnishes in air. Reacts with water. Flammable dust. Thulium is found with other rare earths in the minerals gadolinite, euxenite, xenotime and monazite. Radioactive thulium is used to power portable X-ray machines, eliminating the need for electrical equipment.
Generalic, Eni. "Thulium." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. {Date of access}. <https://glossary.periodni.com>.
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