Elemenat iz grupe obojenih retkih zemalja, atomska težina 169.4, redni broj 69, znak Tm.
Sinonimi: Tm | atomic number 69
ETYM New Lat. Related to Thule.
Soft, silver-white, malleable and ductile, metallic element, of the lanthanide series, symbol Tm, atomic number 69, atomic weight 168.94. It is the least abundant of the rare-earth metals, and was first found in gadolinite and various other minerals. It is used in arc lighting.
The X-ray-emitting isotope Tm-170 is used in portable X-ray units. Thulium was named by French chemist Paul Lecoq de Boisbaudran 1886 after the northland, Thule.
A soft silvery metallic element of the rare earth group; isotope 170 emits X-rays and is used in small portable X-ray machines; it occurs in monazite and apatite and xenotime; SYN. Tm, atomic number 69.