lanthanum

[ lan-thuh-nuhm ]

/ ˈlæn θə nəm /

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noun Chemistry.

a rare-earth, trivalent, metallic element, allied to aluminum, found in certain minerals, as monazite. Symbol: La; atomic weight: 138.91; atomic number: 57; specific gravity: 6.15 at 20°C.

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Origin of lanthanum

<New Latin (1841), equivalent to lanthan- (<Greek lanthánein to escape notice; referring to its position on the periodic table) + -um, variant of -ium-ium

Words nearby lanthanum

lantern ring, lantern slide, lantern wheel, lanthanide, lanthanide series, lanthanum, lanthorn, Lantsang, lanuginose, lanugo, Lanús

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use lanthanum in a sentence

Later in the decade, physicists began turning to other elements such as rubidium and lanthanum.
We finally have a working supersolid. Here’s why that matters.|Claire Maldarelli|August 23, 2021|Popular-Science
The chemical structure is similar to that of the 2018 superconductor made of lanthanum and hydrogen, where a cage of hydrogen atoms surrounds a lanthanum atom.
Can room-temperature superconductors work without extreme pressure?|Emily Conover|March 19, 2021|Science News
By adding in another element, such as lanthanum or yttrium, scientists have created superconductors that function similar to the elusive metallic hydrogen, but at lower pressures.
Can room-temperature superconductors work without extreme pressure?|Emily Conover|March 19, 2021|Science News
A few years later, two groups, one led by Eremets and another involving Hemley and physicist Maddury Somayazulu, studied a high-pressure compound of lanthanum and hydrogen.
The first room-temperature superconductor has finally been found|Emily Conover|October 14, 2020|Science News

Not to mention rare elements such as lanthanum, cerium, and neodymium, essential to modern technology and commanding high prices.
Afghanistan’s Mineral Wealth Could Be a Bonanza—or Lead to Disaster|Dr. Cheryl Benard|July 4, 2012|DAILY BEAST
Lanthanum sulphide, La2S3, is a yellow powder, obtained when the oxide is heated in the vapour of carbon bisulphide.
Encyclopaedia Britannica, 11th Edition, Volume 16, Slice 2|Various
Lanthanum hydroxide, La(OH)3, is a white amorphous powder formed by precipitating lanthanum salts by potassium hydroxide.
Encyclopaedia Britannica, 11th Edition, Volume 16, Slice 2|Various
Lanthanum, lan′tha-num, n. a metal discovered in 1839 in cerite, a hydrated silicate of cerium.
Chambers's Twentieth Century Dictionary (part 2 of 4: E-M)|Various
During an absence of several days, the inventor left a mantle of lanthanum oxide locked up in his laboratory.
Inventors at Work|George Iles
Didymium, a rare metallic element, occurring along with lanthanum in the mineral cerite as discovered by Mosander in 1842.
The New Gresham Encyclopedia|Various

British Dictionary definitions for lanthanum

lanthanum

/ (ˈlænθənəm) /

noun

a silvery-white ductile metallic element of the lanthanide series, occurring principally in bastnaesite and monazite: used in pyrophoric alloys, electronic devices, and in glass manufacture. Symbol: La; atomic no: 57; atomic wt: 138.9055; valency: 3; relative density: 6.145; melting pt: 918°C; boiling pt: 3464°C

Word Origin for lanthanum

C19: New Latin, from Greek lanthanein to lie unseen

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for lanthanum

lanthanum

[ lăn′thə-nəm ]

A soft, malleable, silvery-white metallic element of the lanthanide series. It is used to make glass for lenses and lights for movie and television studios. Atomic number 57; atomic weight 138.91; melting point 920°C; boiling point 3,469°C; specific gravity 5.98 to 6.186; valence 3. See Periodic Table.