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

lanthanum

/ lăn′thə-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.
2. See Periodic Table

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

Word History and Origins

Origin of lanthanum¹

C19: New Latin, from Greek lanthanein to lie unseen

Example Sentences

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

From 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.

From 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.

From 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.

From Science News

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

From The Daily Beast

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

From Project Gutenberg

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

From Project Gutenberg

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

From Project Gutenberg

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

From Project Gutenberg

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

From Project Gutenberg