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Chemical, physical and material properties and data of the chemical element Lawrencium.



Lawrencium - chemical symbol Lr, atomic number 103 - is a short-lived, radioactive, only artificially accessible, metallic, chemical element from the actinide group (transuranic element).

Lawrencium is an unstable element that was first synthesized in 1961 by bombarding Californium with Boron atoms:

25298Cf + 115B → 263103Lr* → 258103Lr + 5 10n.

Due to lawrencium's short lifespan and the high level of technical effort required to produce it, very little is known about its chemical and physical properties. For practical applications, the element has no meaning.


General Information about Lawrencium

Regular nameLawrenciumChemical symbolLrOther namesElement 103Systematic nameUnniltrium, Unt (obsolete)Historical namesLw: symbol used until 1997Name meaning, originErnest Orlando Lawrence, nuclear physicist, 1901 - 1958Discovery (year)1961 - Lawrence Berkeley National Laboratory (USA) and Joint Institute for Nuclear Research (Russia)OccurenceOnly artificially producible chemical element with no practical meaning.Position in the PSEGroup 3, period 7, p-blockGroup membershipActinide series, transuranium element, metals


Atomar Properties of Lawrencium

Atomic number Z103 = number of protonsStandard Atomic Weight266.11983 (56)


Electron configuration of Lawrencium


Abbreviated form: [Rn] 5f14 7s2 7p1.


Ionization Energies of Lawrencium

The following table lists the ionization energies IE (ionization potentials); the IE is the energy required in electron volts (eV) per atom to separate a given electron from an Lawrencium atom.

The first ionization energy of lawrencium was determined experimentally for the first time in 2015 [9].



Isotopic Data of Lawrencium

An overview of the nuclides as well as the isotopic data and properties are listed on the following page: Lawrencium isotopes.


Chemistry of Lawrencium

Little is known about the chemical behavior of lawrencium. On the one hand, this is due to the considerable production costs and the instability and high radioactivity of the metal and its compounds. The element occurs in lawrencium compounds exclusively in the +III oxidation state; accordingly, it occurs in aqueous solution as the Lr3+ ion and has three valence electrons.


Valence electrons3Oxidation states+IIIElectronegativity1.3 (Pauling original)
1.30 (Pauling)
Electron affinity-0.31 eV
-30.04 kJ mol-1


Standard Electrode Potential

E0 (V)SymbolNoxName Ox.
Name Red.
-1.96Lr+ III
Lawrencium(III) cation
⇄ Lr (s)
+ 3 e-


Material and Physical Properties

The table below lists some physical data and material properties of pure lawrencium. Due to the poor availability, these are forecasts.

Melting point1627 °CDensity14.4 g cm-3 (20 °C)


External Data, Identifiers

CAS registry number22537-19-5InChI =1S/LrInChIKeyCNQCVBJFEGMYDW-UHFFFAOYSA-NPubChem ID31192


Literature Sources and References

[1] - Albert Ghiorso, Torbjørn Sikkeland, Almon E. Larsh, Robert M. Latimer:
New Element, Lawrencium, Atomic Number 103.
In: Physical Review Letters, (1961), DOI 10.1103/PhysRevLett.6.473.

[2] - Kari Eskola, Pirkko Eskola, Matti Nurmia, Albert Ghiorso:
Studies of Lawrencium Isotopes with Mass Numbers 255 Through 260.
In: Physical Review C, (1971), DOI 10.1103/PhysRevC.4.632.

[3] - L. J. Nugent et al.:
Electronic configuration in the ground state of atomic lawrencium.
In: Physical Review A, (1974), DOI 10.1103/PhysRevA.9.2270.

[4] - Ephraim Eliav et al.:
Transition energies of ytterbium, lutetium, and lawrencium by the relativistic coupled-cluster method.
In: Physical Review A, (1995), DOI 10.1103/PhysRevA.52.291.

[5] - Yu Zou, C. Froese Fischer:
Resonance Transition Energies and Oscillator Strengths in Lutetium and Lawrencium.
In: Physical Review Letters, (2002), DOI 10.1103/PhysRevLett.88.183001.

[6] - Robert J. Silva:
Fermium, Mendelevium, Nobelium, and Lawrencium.
In: The Chemistry of the Actinide and Transactinide Elements, (2006), DOI 10.1007/1-4020-3598-5_13.

[7] - A. Borschevsky et al.:
Transition energies of atomic lawrencium.
In: EPJD, (2007), DOI 10.1140/epjd/e2007-00130-9.

[8] - Andreas Türler:
Lawrencium bridges a knowledge gap.
In: Nature, (2015), DOI 10.1038/520166a.

[9] - T. K. Sato, M. Asai, A. Borschevsky, T. Stora et al.:
Measurement of the first ionization potential of lawrencium, element 103.
In: Nature, (2015), DOI 10.1038/nature14342.

[10] - Wen-Hua Xuab, Pekka Pyykkö:
Is the chemistry of lawrencium peculiar?.
In: PCCP - Physical Chemistry Chemical Physics, (2016), DOI 10.1039/C6CP02706G.

[11] - Jeffrey T. Kwarsick, Jennifer L. Pore, Jacklyn M. Gates et al.:
Assessment of the Second-Ionization Potential of Lawrencium: Investigating the End of the Actinide Series with a One-Atom-at-a-Time Gas-Phase Ion Chemistry Technique.
In: The Journal of Physical Chemistry A, (2021), DOI 10.1021/acs.jpca.1c01961.

[12] - E. V. Kahl, S. Raeder, E. Eliav, A. Borschevsky, J. C. Berengut:
Ab initio calculations of the spectrum of lawrencium.
In: Physical Review A, (2021), DOI 10.1103/PhysRevA.104.052810.


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Last update: 2022-11-30

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