lutetium

American  

[loo-tee-shee-uhm] / luˈti ʃi əm /

Or lutecium

noun

Chemistry.

1. a trivalent rare-earth element. Lu; 174.97; 71.

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lutetium British  

/ lʊˈtiːʃɪəm /

noun

1. a silvery-white metallic element of the lanthanide series, occurring in monazite and used as a catalyst in cracking, alkylation, and polymerization. Symbol: Lu; atomic no: 71; atomic wt: 174.967; valency: 3; relative density: 9.841; melting pt: 1663°C; boiling pt: 3402°C

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lutetium Scientific  

/ lo̅o̅-tē′shē-əm /

1. A silvery-white metallic element of the lanthanide series that is used in nuclear technology. Its radioactive isotope is used in determining the age of meteorites. Atomic number 71; atomic weight 174.97; melting point 1,663°C; boiling point 3,395°C; specific gravity 9.840 (at 25°C); valence 3.

2. See Periodic Table

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Etymology

Origin of lutetium

1905–10; < Latin Lūtēt ( ia ) Paris + -ium

Example Sentences

Heavy rare-earth elements include dysprosium, terbium, holmium, erbium, thulium, ytterbium, lutetium, and yttrium.

From Barron's • Nov. 13, 2025

This unusual imbalance suggested that liquid water had once seeped through the rocks, effectively leaching lutetium out of them.

From Science Daily • Oct. 16, 2025

For instance, the material described in the paper was supposed to have around three hydrogen atoms for every lutetium atom.

From Scientific American • Nov. 8, 2023

The 17 elements are: lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium.

From Reuters • Jul. 5, 2023

Dr. Dias’s material is made of lutetium, a silvery-white rare earth metal, along with hydrogen and a little bit of nitrogen.

From New York Times • Jun. 23, 2023