Lawrencium (Lr)

Appearance unknown, however it is most likely silvery-white or grey and metallic. Lawrencium is a synthetic rare-earth metal. There are eight known radioisotopes, the most stable being Lr-262 with a half-life of 3.6 hours. Due to the short half-life of lawrencium, and its radioactivity, there are no known uses for it. Identified by Albert Ghiorso in 1961 at Berkeley. It was produced by bombarding californium with boron ions. The name is temporary IUPAC nomenclature, the origin of the name comes from Ernest O. Lawrence, the inventor of the cyclotron. If sufficient amounts of lawrencium were produced, it would pose a radiation hazard.

Atomic Number	103
Atomic Weight	262
Mass Number	251

Group
Period	7
Block	f

Protons	103 p⁺
Neutrons	148 n⁰
Electrons	103 e^-

Properties

Energy
Atomic Radius
Molar Volume
Covalent Radius	161 pm 141 pm
Metallic Radius
Ionic Radius	107.4 pm
Crystal Radius	121.4 pm
Van der Waals Radius	246 pm 323.6 pm
Density	15.6 g/cm³
Proton Affinity
Electron Affinity
Ionization Energy	4.9 eV/particle 14.3 eV/particle 21.4 eV/particle 43.6 eV/particle 56 eV/particle 80 eV/particle 96 eV/particle 121 eV/particle 143 eV/particle 165 eV/particle 197 eV/particle 216 eV/particle 244 eV/particle 269 eV/particle 290 eV/particle 320 eV/particle 344 eV/particle 374 eV/particle 403 eV/particle 431 eV/particle 460 eV/particle 487 eV/particle 510 eV/particle 540 eV/particle 560 eV/particle 745 eV/particle 779 eV/particle 814 eV/particle 852 eV/particle 888 eV/particle 922 eV/particle 985 eV/particle 1,020 eV/particle 1,061 eV/particle 1,098 eV/particle 1,280 eV/particle 1,320 eV/particle 1,360 eV/particle 1,410 eV/particle 1,570 eV/particle 1,620 eV/particle 1,760 eV/particle 1,810 eV/particle 2,010 eV/particle 2,100 eV/particle 2,190 eV/particle 2,290 eV/particle 2,380 eV/particle 2,470 eV/particle 2,570 eV/particle 2,670 eV/particle 2,780 eV/particle 2,860 eV/particle 2,960 eV/particle 3,060 eV/particle 3,150 eV/particle 3,250 eV/particle 3,741 eV/particle 3,821 eV/particle 3,906 eV/particle 3,996 eV/particle 4,082 eV/particle 4,165 eV/particle 4,360 eV/particle 4,448 eV/particle 4,540 eV/particle 4,630 eV/particle 4,990 eV/particle 5,070 eV/particle 5,160 eV/particle 5,250 eV/particle 5,920 eV/particle 6,030 eV/particle 6,290 eV/particle 6,390 eV/particle 9,920 eV/particle 10,110 eV/particle 10,310 eV/particle 10,520 eV/particle 10,720 eV/particle 10,920 eV/particle 11,480 eV/particle 11,680 eV/particle 11,910 eV/particle 12,120 eV/particle 12,710 eV/particle 12,890 eV/particle 13,090 eV/particle 13,300 eV/particle 15,300 eV/particle 15,600 eV/particle 16,000 eV/particle 16,200 eV/particle 32,400 eV/particle 32,900 eV/particle 33,400 eV/particle 33,900 eV/particle 41,600 eV/particle 42,300 eV/particle 43,200 eV/particle 43,759 eV/particle 172,930 eV/particle

Heat of Vaporization
Heat of Fusion
Heat of Formation
Electrons
Electron Shells	2, 8, 18, 32, 32, 8, 3

Valence Electrons	3

Electron Configuration	[Rn] 5f¹⁴ 7s² 7p¹

Oxidation States	3
Electronegativity	0.24844
Electrophilicity
Phases
Phase	Solid
Gas Phase
Boiling Point
Melting Point	1,900.15 K
Critical Pressure
Critical Temperature
Triple Point
Visual
Color	Colorless #ffffff #c70066 #c70066
Appearance
Refractive Index
Thermodynamic Properties
Thermal Conductivity
Thermal Expansion
Molar Heat Capacity
Specific Heat Capacity
Heat Capacity Ratio (Adiabatic Index)
Electrical Properties
Type
Electrical Conductivity
Electrical Resistivity
Superconducting Point
Magnetism
Type
Magnetic Susceptibility (Mass)
Magnetic Susceptibility (Molar)
Magnetic Susceptibility (Volume)
Magnetic Ordering
Curie Point
Neel Point
Structure
Crystal Structure	()
Lattice Constant
Lattice Angles
Mechanical Properties
Hardness
Bulk Modulus
Shear Modulus
Young Modulus
Poisson Ratio
Speed of Sound
Classification
Category	Actinides, Transition metals
CAS Group
IUPAC Group
Glawe Number	47
Mendeleev Number	42
Pettifor Number	34
Geochemical Class
Goldschmidt Class	synthetic
Other
Gas Basicity
Dipole Polarizability	320 ± 20 a₀
C6 Dispersion Coefficient
Allotropes
Neutron Cross Section
Neutron Mass Absorption
Quantum Numbers	2P1/2
Space Group	()

Isotopes of Lawrencium

Stable Isotopes	0
Unstable Isotopes	16
Radioactive Isotopes	16

²⁵¹Lr

Abundance	Radioactive ☢️
Relative Atomic Mass	251.094289 ± 0.000215 Da
Mass Number	251
G-Factor
Half Life
Spin
Quadrupole Moment
Discovery Year
Parity

²⁵¹Lr Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%
α (α emission)	%

²⁵²Lr

Abundance	Radioactive ☢️
Relative Atomic Mass	252.095048 ± 0.000198 Da
Mass Number	252
G-Factor
Half Life	369 ± 75 ms
Spin	7
Quadrupole Moment
Discovery Year	2001
Parity	-

²⁵²Lr Decay Modes

Decay Mode	Intensity
α (α emission)	98%
SF (spontaneous fission)	2%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%

²⁵³Lr

Abundance	Radioactive ☢️
Relative Atomic Mass	253.09503385 ± 0.000176634 Da
Mass Number	253
G-Factor
Half Life	632 ± 46 ms
Spin	7/2
Quadrupole Moment
Discovery Year	1985
Parity	-

²⁵³Lr Decay Modes

Decay Mode	Intensity
α (α emission)	90%
SF (spontaneous fission)	1%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%

²⁵⁴Lr

Abundance	Radioactive ☢️
Relative Atomic Mass	254.096238813 ± 0.000098026 Da
Mass Number	254
G-Factor
Half Life	12 ± 0.9 s
Spin	4
Quadrupole Moment
Discovery Year	1981
Parity	+

²⁵⁴Lr Decay Modes

Decay Mode	Intensity
α (α emission)	71.7%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	28.3%
SF (spontaneous fission)	0.1%

²⁵⁵Lr

Abundance	Radioactive ☢️
Relative Atomic Mass	255.096562399 ± 0.000019 Da
Mass Number	255
G-Factor
Half Life	31.1 ± 1.1 s
Spin	1/2
Quadrupole Moment	0
Discovery Year	1971
Parity	-

²⁵⁵Lr Decay Modes

Decay Mode	Intensity
α (α emission)	99.7%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	0.3%
SF (spontaneous fission)	%

²⁵⁶Lr

Abundance	Radioactive ☢️
Relative Atomic Mass	256.098494024 ± 0.000089 Da
Mass Number	256
G-Factor	0
Half Life	27.9 ± 1 s
Spin	0
Quadrupole Moment	0
Discovery Year	1965
Parity	-

²⁵⁶Lr Decay Modes

Decay Mode	Intensity
α (α emission)	85%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	15%
SF (spontaneous fission)	0.03%

²⁵⁷Lr

Abundance	Radioactive ☢️
Relative Atomic Mass	257.09948 ± 0.000047 Da
Mass Number	257
G-Factor
Half Life	6 ± 0.4 s
Spin	7/2
Quadrupole Moment
Discovery Year	1971
Parity	-

²⁵⁷Lr Decay Modes

Decay Mode	Intensity
α (α emission)	100%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%
SF (spontaneous fission)	%

²⁵⁸Lr

Abundance	Radioactive ☢️
Relative Atomic Mass	258.101753 ± 0.000109 Da
Mass Number	258
G-Factor
Half Life	3.92 ± 0.33 s
Spin
Quadrupole Moment
Discovery Year	1971
Parity

²⁵⁸Lr Decay Modes

Decay Mode	Intensity
α (α emission)	97.4%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	2.6%

²⁵⁹Lr

Abundance	Radioactive ☢️
Relative Atomic Mass	259.1029 ± 0.000076 Da
Mass Number	259
G-Factor
Half Life	6.2 ± 0.3 s
Spin	1/2
Quadrupole Moment	0
Discovery Year	1971
Parity	-

²⁵⁹Lr Decay Modes

Decay Mode	Intensity
α (α emission)	78%
SF (spontaneous fission)	22%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%

²⁶⁰Lr

Abundance	Radioactive ☢️
Relative Atomic Mass	260.105504 ± 0.000134 Da
Mass Number	260
G-Factor
Half Life	3 ± 0.5 m
Spin
Quadrupole Moment
Discovery Year	1971
Parity

²⁶⁰Lr Decay Modes

Decay Mode	Intensity
α (α emission)	80%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	20%

²⁶¹Lr

Abundance	Radioactive ☢️
Relative Atomic Mass	261.106879 ± 0.000215 Da
Mass Number	261
G-Factor
Half Life	39 ± 12 m
Spin	1/2
Quadrupole Moment	0
Discovery Year	1987
Parity	-

²⁶¹Lr Decay Modes

Decay Mode	Intensity
SF (spontaneous fission)	100%
α (α emission)	%

²⁶²Lr

Abundance	Radioactive ☢️
Relative Atomic Mass	262.109615 ± 0.000215 Da
Mass Number	262
G-Factor
Half Life
Spin
Quadrupole Moment
Discovery Year	1987
Parity

²⁶²Lr Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%
SF (spontaneous fission)	10%
α (α emission)	%

²⁶³Lr

Abundance	Radioactive ☢️
Relative Atomic Mass	263.111293 ± 0.00024 Da
Mass Number	263
G-Factor
Half Life
Spin	1/2
Quadrupole Moment	0
Discovery Year
Parity	-

²⁶³Lr Decay Modes

Decay Mode	Intensity
α (α emission)	%

²⁶⁴Lr

Abundance	Radioactive ☢️
Relative Atomic Mass	264.114198 ± 0.000468 Da
Mass Number	264
G-Factor
Half Life
Spin
Quadrupole Moment
Discovery Year
Parity

²⁶⁴Lr Decay Modes

Decay Mode	Intensity
α (α emission)	%
SF (spontaneous fission)	%

²⁶⁵Lr

Abundance	Radioactive ☢️
Relative Atomic Mass	265.116193 ± 0.000587 Da
Mass Number	265
G-Factor
Half Life
Spin	1/2
Quadrupole Moment	0
Discovery Year
Parity	-

²⁶⁵Lr Decay Modes

Decay Mode	Intensity
α (α emission)	%
SF (spontaneous fission)	%

²⁶⁶Lr

Abundance	Radioactive ☢️
Relative Atomic Mass	266.119874 ± 0.000579 Da
Mass Number	266
G-Factor
Half Life	22 ± 14 h
Spin
Quadrupole Moment
Discovery Year	2014
Parity

²⁶⁶Lr Decay Modes

Decay Mode	Intensity
SF (spontaneous fission)	100%

History

Lawrencium was discovered by Albert Ghiorso, Torbjørn Sikkeland, Almon Larsh and Robert M. Latimer in 1961 at the University of California, Berkeley. It was produced by the bombardment of californium with boron atoms. Lawrencium was the last member of the actinide series to be discovered. Named after Ernest O. Lawrence, inventor of the cyclotron

Discoverers	A.Ghiorso, T.Sikkeland, A.E.Larsh, R.M.Latimer
Discovery Location	United States
Discovery Year	1961
Etymology (Name Origin)	Named in honor of Ernest O. Lawrence, inventor of the cyclotron.
Pronunciation	lor-ENS-i-em (English)

Lawrencium is harmful due to its radioactivity

Lawrencium is a trivalent ion in aqueous solution

Uses

Lawrencium is used for scientific research purposes only. It has no significant commercial applications.

Sources

Produced by bombarding californium with boron ions.

Abundance
Abundance in Earth's crust
Abundance in Oceans
Abundance in Human Body	0 %
Abundance in Meteor	0 %
Abundance in Sun	0 %
Abundance in Universe	0 %

Nuclear Screening Constants

Lawrencium on ChemicalAid

Australian Educational Vocabulary ID	scot/3536
CAS Registry Number	22537-19-5
ChEBI ID	33397
ChemSpider ID	28934
DSSTOX compound identifier	DTXCID8099548
DSSTox substance ID	DTXSID30177057
Den Store Danske ID	lawrencium
Elhuyar ZTH ID	027359
Encyclopædia Britannica Online ID	science/lawrencium
Freebase ID	/m/025r_0l
GND ID	4166972-1
Gran Enciclopèdia Catalana ID	0118987
Great Russian Encyclopedia Online ID	2159168
InChI	InChI=1S/Lr
InChIKey	CNQCVBJFEGMYDW-UHFFFAOYSA-N
KBpedia ID	Lawrencium
MeSH descriptor ID	D007852
OmegaWiki Defined Meaning	161353
PubChem CID	31192
Römpp online ID	RD-12-00553
Store norske leksikon ID	lawrencium
Treccani ID	laurenzio
UNII	QRT37X99RQ
WordNet 3.1 Synset ID	14667501-n

Lawrencium (Lr)

Properties

Isotopes of Lawrencium

251Lr

251Lr Decay Modes

252Lr

252Lr Decay Modes

253Lr

253Lr Decay Modes

254Lr

254Lr Decay Modes

255Lr

255Lr Decay Modes

256Lr

256Lr Decay Modes

257Lr

257Lr Decay Modes

258Lr

258Lr Decay Modes

259Lr

259Lr Decay Modes

260Lr

260Lr Decay Modes

261Lr

261Lr Decay Modes

262Lr

262Lr Decay Modes

263Lr

263Lr Decay Modes

264Lr

264Lr Decay Modes

265Lr

265Lr Decay Modes

266Lr

266Lr Decay Modes