What is the chemical symbol lanthanum


Lanthanum - chemical symbol La, atomic number 57 - is a silver-white, ductile chemical element of the scandium group, the initial member of the lanthanoids and a heavy metal from the group of rare earth metals, occurring in three modifications.


Overview: General data on lanthanum


The La atom - and thus the chemical element lanthanum - is clearly defined by the 57 positively charged protons in the atomic nucleus. The same number of electrons ensures the electrical balance in the uncharged lanthanum atom.

The nuclear building blocks of the neutrons ensure that there are differences between the atomic nuclei. These types of atoms are under the term Lanthanum isotopes summarized (isotope data: see there).

The earthly lanthanum deposits consist of a mixture of two lanthanum isotopes of different mass; the relative atomic mass of lanthanum is given as 138.90547 (7) u.


Electron configuration

symbolOZshort form1s2s2p3s3p3d4s4p4d4f5s5p5d5f6s6p6d6f
La57[Xe] 5d1 6s2226261026102612


Ionization energies

The following table lists the binding energies or the ionization energies IE of the lanthanum, i.e. the energy required in electron volts (eV) to separate a specific electron from a La atom.

1. IE: 5.5769 eV2. IE: 11.059 eV3. IE: 19.1774 eV4. IE: 49.95 eV5. IE: 61.6 eV6. IE: eV


Electron binding energy

The following table lists the electron binding energies of the individual lanthanum electrons in the respective orbitals. The values ​​are given in electron volts (eV).









Further data


Spectral lines of the lanthanum

The following figure shows an emission spectrum of the lanthanum with the characteristic spectral lines in the visible wavelength range between 400 and 700 nm:



Chemical data


Standard potentials

Normal potential of the lanthanum:

E.0 (V)NoxName Ox.Ox.e-Red.Name Red.Nox
-2,9+ IIILanthanum hydroxideLa (OH)3+ 3 e-La (s) + 3 OH-Lanthanum0
-2,379+ IIILanthanum (III) cationLa3++ 3 e-Read)Lanthanum0


Material and physical properties of lanthanum

The following table lists some physical data and material properties of the pure metallic lanthanum.



[1] - C. G. Mosander:
About cerium, lanthanum and didymium, as well as ytter earth, erbium and terbium.
In: Justus Lebig's Annals of Chemistry, 1843, DOI 10.1002 / jlac.18430480218.

[2] - C. G. Mosander:
About the new metals lanthanium and didymium accompanying the cerium, as well as about the new metals erbium and terbium occurring with the ytterede.
In: Annals of Physics, 1843, DOI 10.1002 / andp.18431361008.

[3] - C. G. Mosander:
About cerium, lanthanium and didymium.
In: Pharmacy Archives, 1844, DOI 10.1002 / ardp.18440870127.

[4] - Jörg Wittig:
The electronic structure of lanthanum and cerium.
In: Physical sheets, 1977, DOI 10.1002 / phbl. 19770330305, open access.


External information offers

Group items - information

Lanthanoid separation
Extraction and separation of lanthanides. FH Münster - Format: PDF

Lecture materials: chemistry of metals. University of Freiburg

Discovery of the lanthanoids; Peculiarities of the lanthanoids; Electron configurations; Ion exchange process; Lanthanide contraction; Oxidation states; Use. University of Bayreuth

General, separation, extraction, properties, 4f orbitals etc. Bielefeld University

Scandium group
Lecture notes: Chemistry of Metals. University of Freiburg

Individual connections

Lanthanum and lanthanum compounds
Chemical database: physical and chemical properties, safety data sheets, commercially available substances and compounds; various search criteria including structure search

Synthesis, manufacture, production

Analysis and determination

Organometallic chemistry and reagents

Geochemistry and biogeochemistry

Minerals containing lanthanum
Information on lanthanum and the lanthanum minerals. Minerals Atlas

Rare earth minerals
List and percentage composition of the individual rare earths contained in nature occurring minerals


Lanthanum complexes
Complexes of zinc, cadmium, lanthanum, cerium and samarium. Dissertation, 2005. University of Kaiserslautern

Lanthanide-labeled peptides and nucleic acids
Synthesis and bioanalytical application of lanthanide-labeled peptides and nucleic acids. University of Heidelberg, 2009

Lanthanide metal surfaces
Scanning tunnel spectroscopy on lanthanide metal surfaces. Correlated electronic structure and dynamics of excited states. Dissertation, 2004. FU Berlin

Lanthanoid alkyl aluminates
Dissertation, 2001. Technical University of Munich - Format: PDF

Oxide and hydroxide phases
Representation of oxide and hydroxide phases containing lanthanides: new concepts for controlling morphology and functional properties. Saarland University, 2009

Polyfunctional ligand systems
Syntheses and structures of new lanthanide and mercury complexes with polyfunctional ligand systems. University of Göttingen, 2003

Sigma-linked ligands
Synthesis and characterization of compounds of the lanthanoids with sigma-bound ligands. University of Göttingen, 2008

Articles and reports

Fair exchange
Lanthanum chloride catalyzes hydrogen-chlorine exchange between chlorinated hydrocarbons. Article, June 2008


Category: Chemical elements

Updated on 24.02.2020.

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