A soft, silvery-white, malleable, ductile, metallic rare-earth element, obtained chiefly from monazite and bastnaesite and used in glass manufacture and with other rare earths in carbon lights for movie and television studio lighting. Atomic number 57; atomic weight 138.91; melting point 920°C; boiling point 3,464°C; specific gravity 6.145 (at 25°C); valence 2, 3.
A soft, malleable, silvery chemical element, one of the rare-earth elements and the first member of the lanthanide series: symbol, La; at. no. 57
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.
New Latin from Greek lanthaneinto escape notice (from the finding of the element hidden in oxide of cerium)
Soc., 1901, 17, p. 63) by ignition of lanthanum sulphate at 500Ã‚° C., the value obtained being 139 (O =16).
of yttria, Y203, and 42.75 of the oxides of erbium, cerium, didymium, lanthanum, iron, beryllium, calcium, magnesium and sodium.
In 1841 Mosander, having in 1839 discovered a new element lanthanum in the mineral cerite, isolated this element and also a hitherto unrecognized substance, didymia, from crude yttria, and two years later he announced the determination of two fresh constituents of the same earth, naming them erbia and terbia.
LANTHANUM [[[symbol]] La, atomic weight 139.0 (0=16)] one of the metals of the cerium group of rare earths.
For details of the complex process for the separation of the lanthanum salts from cerite, see R.