Lawrencium

103

nobelium ← lawrencium → rutherfordium


Lu
↑
Lr
↓
(Upt)




periodic table




General


Name, Symbol, Number

lawrencium, Lr, 103


Chemical series
actinides


Group, Period, Block

n/a, 7, d


Appearance
unknown, probably silvery
white or metallic gray


Atomic mass
(262) g/mol


Electron configuration
probably [Rn] 5f14 7s2 6d1


Electrons per shell
2, 8, 18, 32, 32, 8, 3


Physical properties


Phase
presumably a solid


Melting point
1900 K
(1627 °C, 2961 °F)


Atomic properties


Oxidation states
3


Electronegativity
1.3 (Pauling scale)


Ionization energies

1st: 470 kJ/mol


Miscellaneous


CAS registry number
22537-19-5


Notable isotopes




Main article: Isotopes of lawrencium


iso

NA

half-life

DM

DE (MeV)

DP


262Lr

syn

~4 h








Lawrencium (chemical symbol Lr, atomic number 103), once known as eka-lutetium, is a radioactive synthetic element in the periodic table. Its most stable isotope is 262Lr, with a half-life of approximately four hours. It is synthesized from californium and is of interest mainly for research purposes. It has no practical applications at this time.

Contents

1 Etymology
2 History
3 Notable characteristics
4 See also
5 Notes
6 References
7 External links
8 Credits



Etymology
The origin of the name, preferred by the American Chemical Society, is in reference to Ernest O. Lawrence, inventor of the cyclotron. The symbol Lw was originally used but in 1963 it was changed to Lr. In August 1997, the International Union of Pure and Applied Chemistry (IUPAC) ratified the name lawrencium and symbol Lr during a meeting in Geneva. Unniltrium was sometimes used as a temporary, systematic element name until that time.

History
Lawrencium was discovered by Albert Ghiorso, Torbjørn Sikkeland, Almon Larsh and Robert M. Latimer on February 14, 1961, at the Berkeley Radiation Laboratory (now called Lawrence Berkeley National Laboratory) on the University of California, Berkeley campus. It was produced by bombarding a three milligram target composed of three isotopes of californium with boron-10 and boron-11 ions in the Heavy Ion Linear Accelerator (HILAC).
The transmutation nuclei became electrically charged, recoiled with a helium atmosphere and were collected on a thin copper conveyor tape. This tape was then moved in order to place the collected atoms in front of a series of solid-state detectors. The Berkeley team reported that the isotope 257103 was detected in this manner and decayed by emitting an 8.6 MeV alpha particle with a half-life of 4.2 seconds.
In 1967, researchers in Dubna, Russia reported that they were not able to confirm an alpha emitter with a half-life of 4.2 seconds as 257103. This assignment has since been changed to 258Lr or 259Lr. Eleven isotopes of element 103 have been synthesized with 262Lr being the longest lived, with a half-life of 216 minutes (it decays into 256No). The isotopes of lawrencium decay via alpha emission, spontaneous fission, and electron capture (in order of most to least common types).

Notable characteristics
If one were to follow a strict correlation between periodic table blocks and chemical series for neutral atoms, lawrencium would be described as a transition metal because it is in the d-block. The International Union of Pure and Applied Chemistry (IUPAC), however, recommends that it be classified as an actinide.[1]
The appearance of this element is unknown, but it is likely to be silvery-white or gray and metallic. If sufficient amounts of lawrencium were produced, it would pose a radiation hazard. Very little is known about the chemical properties of this element, but some preliminary work on a few atoms has indicated that it behaves in a manner similar to other actinides.

See also
Chemical element
Inner transition metal
Metal
Periodic table
Radioactive decay
Notes

↑  Nomenclature of Inorganic Chemistry IUPAC Chemical Nomenclature and Structure Representation Division. Retrieved September 24, 2007.


ReferencesISBN links support NWE through referral fees
Emsley, John. Nature's Building Blocks: An A–Z Guide to the Elements. Oxford: Oxford Univ. Press, 2001. ISBN 0198503407
Greenwood, N.N., and A. Earnshaw. Chemistry of the Elements, 2nd ed. Oxford, UK; Burlington, MA: Butterworth-Heinemann, 1998. ISBN 0750633654 Online version Retrieved September 24, 2007.
Hampel, Clifford A. The Encyclopedia of the Chemical Elements. New York: Reinhold Book Corp, 1968. ISBN 0442155980
Morss, Lester R., Norman M. Edelstein, and Jean Fuger, eds. The Chemistry of the Actinide and Transactinide Elements. 3rd ed. 5 vols. Joseph J. Katz, adapter. Dordrecht: Springer, 2006. ISBN 1402035551
Stwertka, Albert. Guide to the Elements. Rev. ed. Oxford: Oxford University Press, 1998. ISBN 0-19-508083-1
External links
All links retrieved October 25, 2022.

Lawrencium WebElements.

Credits
New World Encyclopedia writers and editors rewrote and completed the Wikipedia article
in accordance with New World Encyclopedia standards. This article abides by terms of the Creative Commons CC-by-sa 3.0 License (CC-by-sa), which may be used and disseminated with proper attribution. Credit is due under the terms of this license that can reference both the New World Encyclopedia contributors and the selfless volunteer contributors of the Wikimedia Foundation. To cite this article click here for a list of acceptable citing formats.The history of earlier contributions by wikipedians is accessible to researchers here:

Lawrencium  history
The history of this article since it was imported to New World Encyclopedia:

History of "Lawrencium"
Note: Some restrictions may apply to use of individual images which are separately licensed.