Lawrencium

103

262

About Lawrencium

Lawrencium, the last element of the actinide series, was first synthesized at the Lawrence Berkeley National Laboratory in 1961 by the nuclear-physics team headed by Albert Ghiorso. The synthesis was achieved by bombarding a californium target with boron-10 and boron-11 from the heavy ion linear accelerator. This team was responsible for the element being named in honor of Ernest O. Lawrence, who built the first working cyclotron. However, the initial experiments by the Berkeley team did not produce all the data ideally desired to prove an element's existence--this data came from later Berkeley experiments as well as from work by the Russian Joint Institute for Nuclear Research. IUPAC officially recognized both teams as co-discoverers of the element in 1992.

Because only a few atoms have ever been created, and the isotopes have very short half-lives, scientists have not had sufficient opportunity to study the element in detail. Consequently, it has no commercial applications and little is known about its characteristics.

Lawrencium Properties

Lawrencium Bohr Model Lawrencium is a Block D, Group 3, Period 7 element. The number of electrons in each of lawrencium's shells is 2, 8, 18, 32, 32, 8, 3, and its electron configuration is [Rn] 5f¹⁴7s²7p. The lawrencium atom has a Van der Waals radius of 246.pm. In its elemental form, lawrencium's CAS number is 22537-19-5. Lawrencium behaves differently from dipositive nobelium and more like the tripositive elements found earlier in the actinide series. Lawrencium is radioactive and therefore considered toxic. Lawrencium was discovered by Albert Ghiorso, Torbjorn Sikkeland, Almon E. Larsh and Robert M. Latimer at the Lawrence Berkeley National Laboratory in 1961. It was named after Earnest O. Lawrence the inventor of the cyclotron particle accelerator. The symbol for Lawrencium was originally Lw; however, the International Union of Pure and Applied Chemistry (IUPAC) changed the symbol from Lw to Lr in August, 1997.

Lawrencium information, including technical data, properties, and other useful facts are discussed below. Scientific facts such as the atomic structure, ionization energy, abundance on Earth, conductivity and thermal properties are included.

General Properties

Symbol:	Lr
Atomic Number:	103
Atomic Weight:	262
Element Category:	Actinide
Group, Period, Block:	n/a, 7, f
Color:	unknown (presumably metallic/ silvery white/ gray)
Other Names:	Laurenzio, Laurêncio

Physical Properties

Melting Point:	1627°C, 2960.67deg F, 1900.15 K
Boiling Point:	N/A
Density:	N/A
Liquid Density @ Melting Point:	N/A
Density @ 20°C:	N/A
Density of Solid:	N/A
Specific Heat:	N/A
Superconductivity Temperature:	N/A
Triple Point:	N/A
Critical Point:	N/A
Heat of Fusion (kJ·mol^-1):	N/A
Heat of Vaporization (kJ·mol^-1):	N/A
Heat of Atomization (kJ·mol^-1):	308
Thermal Conductivity:	N/A
Thermal Expansion:	N/A
Electrical Resistivity:	N/A
Tensile Strength:	N/A
Molar Heat Capacity:	N/A
Young's Modulus:	N/A
Shear Modulus:	N/A
Bulk Modulus:	N/A
Poisson Ratio:	N/A
Mohs Hardness:	N/A
Vickers Hardness:	N/A
Brinell Hardness:	N/A
Speed of Sound:	N/A
Pauling Electronegativity:	N/A
Sanderson Electronegativity:	N/A
Allred Rochow Electronegativity:	N/A
Mulliken-Jaffe Electronegativity:	N/A
Allen Electronegativity:	N/A
Pauling Electropositivity:	N/A
Reflectivity (%):	N/A
Refractive Index:	N/A

Chemical Properties

Electrons:	103
Protons:	103
Neutrons:	159
Electron Configuration:	[Rn] 5f¹⁴7s²7p
Atomic Radius:	N/A
Atomic Radius, non-bonded (Å):	2.46
Covalent Radius:	N/A
Covalent Radius (Å):	1.61
Van der Waals Radius:	246 pm
Oxidation States:	3 (predicted)
Phase:	Solid (predicted)
Crystal Structure:	N/A
Magnetic Ordering:	N/A
Electron Affinity (kJ·mol^-1)	Unknown
1^st Ionization Energy:	443.8 kJ·mol^-1(estimated)
2^nd Ionization Energy:	1428.0 kJ·mol^-1(estimated)
3^rd Ionization Energy:	2219.1 kJ·mol^-1(estimated)

Identifiers

CAS Number:	22537-19-5
EC Number:	N/A
MDL Number:	N/A
Beilstein Number:	N/A
SMILES Identifier:	[Lr]
InChI Identifier:	InChI=1S/Lr
InChI Key:	CNQCVBJFEGMYDW-UHFFFAOYSA-N
PubChem CID:	31192
ChemSpider ID:	28934

Abundance

Earth - Total:	N/A
Mercury - Total:	N/A
Venus - Total:	N/A
Earth - Seawater (Oceans), ppb by weight:	N/A
Earth - Seawater (Oceans), ppb by atoms:	N/A
Earth - Crust (Crustal Rocks), ppb by weight:	N/A
Earth - Crust (Crustal Rocks), ppb by atoms:	N/A
Sun - Total, ppb by weight:	N/A
Sun - Total, ppb by atoms:	N/A
Stream, ppb by weight:	N/A
Stream, ppb by atoms:	N/A
Meterorite (Carbonaceous), ppb by weight:	N/A
Meterorite (Carbonaceous), ppb by atoms:	N/A
Typical Human Body, ppb by weight:	N/A
Typical Human Body, ppb by atom:	N/A
Universe, ppb by weight:	N/A
Universe, ppb by atom:	N/A

History

Discovered By:	Lawrence Berkeley Nat'l Laboratory
Discovery Date:	1961
First Isolation:	N/A

Isotopes

Lawrencium is an artificial element. It has no stable isotopes.

Nuclide	Isotopic Mass	Half-Life	Mode of Decay	Nuclear Spin	Magnetic Moment	Binding Energy (MeV)	Natural Abundance (% by atom)
²⁵²Lr	252.09526(26)#	390(90) ms [0.36(+11-7) s]	a to ²⁴⁸Md; EC to ²⁵²No; SF	N/A	N/A	1872.72998	-
²⁵³Lr	253.09509(22)#	580(70) ms [0.57(+7-6) s]	a to ²⁴⁹Md; EC to ²⁵³No; SF	(7/2-)	N/A	1887.464966	-
²⁵⁴Lr	254.09648(32)#	13(3) s	a to ²⁵⁰Md; EC to ²⁵⁴No; SF	N/A	N/A	1879.562988	-
²⁵⁵Lr	255.096562(19)	22(4) s	a to ²⁵¹Md; EC to ²⁵⁵No	7/2-#	N/A	1887.464966	-
²⁵⁶Lr	256.09849(9)	27(3) s	a to ²⁵²Md; EC to ²⁵⁶No; SF	N/A	N/A	1893.678955	-
²⁵⁷Lr	256.09849(9)	646(25) ms	a to ²⁵³Md	9/2+#	N/A	1900.964966	-
²⁵⁸Lr	258.10176(11)#	3.9 s	a to ²⁵⁴Md; EC to ²⁵⁸No; SF	N/A	N/A	1906.916016	-
²⁵⁹Lr	259.10290(8)#	6.1 s	a to ²⁵⁵Md; EC to ²⁵⁹No; SF	9/2+#	N/A	1913.954956	-
²⁶⁰Lr	260.10551(13)#	4.1(3) s	a to ²⁵⁶Md; EC to ²⁶⁰No; SF	N/A	N/A	1919.620972	-
²⁶¹Lr	261.10688(22)#	40 m	SF	N/A	N/A	1926.417969	-
²⁶²Lr	262.10961(22)#	3.6 h	EC to ²⁶²No; SF	N/A	N/A	1931.927002	-
²⁶³Lr	263.11136(30)#	s# h;	a to ²⁵⁹Md	N/A	N/A	1938.412964	-
²⁶⁴Lr	264.11420(47)#	10# h	a to ²⁶¹Md	N/A	N/A	N/A	-
²⁶⁵Lr	265.11619(65)#	10# h	a to ²⁶¹Md	N/A	N/A	N/A	-
²⁶⁶Lr	266.11983(56)#	11 h	SF	N/A	N/A	N/A	-