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lanthanum

[ lan-thuh-nuhm ]

noun

, Chemistry.
  1. a rare-earth, trivalent, metallic element, allied to aluminum, found in certain minerals, as monazite. : La; : 138.91; : 57; : 6.15 at 20°C.


lanthanum

/ ˈlænθənəm /

noun

  1. 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
“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


lanthanum

/ lănthə-nəm /

  1. 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.


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Word History and Origins

Origin of lanthanum1

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

Origin of lanthanum1

C19: New Latin, from Greek lanthanein to lie unseen
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Example Sentences

Later in the decade, physicists began turning to other elements such as rubidium and lanthanum.

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.

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.

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.

Not to mention rare elements such as lanthanum, cerium, and neodymium, essential to modern technology and commanding high prices.

Lanthanum sulphide, La2S3, is a yellow powder, obtained when the oxide is heated in the vapour of carbon bisulphide.

Lanthanum hydroxide, La(OH)3, is a white amorphous powder formed by precipitating lanthanum salts by potassium hydroxide.

Lanthanum, lan′tha-num, n. a metal discovered in 1839 in cerite, a hydrated silicate of cerium.

During an absence of several days, the inventor left a mantle of lanthanum oxide locked up in his laboratory.

Didymium, a rare metallic element, occurring along with lanthanum in the mineral cerite as discovered by Mosander in 1842.

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lanthanide serieslanthorn