thulium

Từ điển Oxford Learners Wordfinder Dictionary

noun

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
• Hypernyms:
metallic element, metal
• Substance Holonyms:
apatite, monazite, xenotime