Berkelium (Bk)

Berkelium is the 97th element in the periodic table and has a symbol of Bk and atomic number of 97. It has an atomic weight of (247) and a mass number of 233. Berkelium has ninety-seven protons and one hundred thirty-six neutrons in its nucleus, and ninety-seven electrons in seven shells. It is located in group zero, period seven and block f of the periodic table. Radioactive metallic transuranic element. Belongs to actinoid series. Eight known isotopes, the most common Bk-247, has a half-life of 1.4*10^3 years. First produced by Glenn T. Seaborg and associates in 1949 by bombarding americium-241 with alpha particles.

Atomic Number	97
Atomic Weight	247
Mass Number	233

Group
Period	7
Block	f

Protons	97 p⁺
Neutrons	136 n⁰
Electrons	97 e^-

Properties

Physical Properties
Atomic Radius
Molar Volume
Covalent Radius	168 pm 139 pm
Metallic Radius
Ionic Radius	96 pm 83 pm 93 pm 113.7 pm
Crystal Radius	110 pm 97 pm 107 pm 127.7 pm
Van der Waals Radius	244 pm 333.9 pm
Density	14.78 g/cm³
Energy
Proton Affinity
Electron Affinity
Ionization Energy	6.1978 eV/particle 11.9 eV/particle 21.6 eV/particle 36 eV/particle 56 eV/particle 70.1 eV/particle 90 eV/particle 114 eV/particle 130 eV/particle 147 eV/particle 171 eV/particle 195 eV/particle 218 eV/particle 240 eV/particle 259 eV/particle 279 eV/particle 303 eV/particle 339 eV/particle 361 eV/particle 497 eV/particle 526 eV/particle 557 eV/particle 590 eV/particle 621 eV/particle 652 eV/particle 700 eV/particle 733 eV/particle 768 eV/particle 800 eV/particle 960 eV/particle 1,000 eV/particle 1,040 eV/particle 1,080 eV/particle 1,200 eV/particle 1,240 eV/particle 1,360 eV/particle 1,410 eV/particle 1,550 eV/particle 1,630 eV/particle 1,720 eV/particle 1,800 eV/particle 1,890 eV/particle 1,970 eV/particle 2,050 eV/particle 2,140 eV/particle 2,240 eV/particle 2,320 eV/particle 2,410 eV/particle 2,490 eV/particle 2,580 eV/particle 2,670 eV/particle 3,080 eV/particle 3,154 eV/particle 3,232 eV/particle 3,315 eV/particle 3,393 eV/particle 3,469 eV/particle 3,630 eV/particle 3,709 eV/particle 3,797 eV/particle 3,877 eV/particle 4,202 eV/particle 4,281 eV/particle 4,365 eV/particle 4,445 eV/particle 4,940 eV/particle 5,040 eV/particle 5,270 eV/particle 5,360 eV/particle 8,500 eV/particle 8,670 eV/particle 8,850 eV/particle 9,050 eV/particle 9,240 eV/particle 9,420 eV/particle 9,880 eV/particle 10,070 eV/particle 10,280 eV/particle 10,480 eV/particle 11,020 eV/particle 11,190 eV/particle 11,380 eV/particle 11,540 eV/particle 13,090 eV/particle 13,300 eV/particle 13,720 eV/particle 13,910 eV/particle 28,380 eV/particle 28,800 eV/particle 29,300 eV/particle 29,800 eV/particle 35,500 eV/particle 36,200 eV/particle 37,000 eV/particle 37,457.6 eV/particle 146,904.7 eV/particle 149,398 eV/particle

Heat of Vaporization
Heat of Fusion
Heat of Formation	310 kJ/mol
Electrons
Electron Shells	2, 8, 18, 32, 27, 8, 2

Valence Electrons	2

Electron Configuration	[Rn] 5f⁹ 7s²

Oxidation States	2, 3, 4, 5
Electronegativity	0.19315
Electrophilicity
Phases
Phase	Solid
Gas Phase
Boiling Point
Melting Point	1,259.15 K
Critical Pressure
Critical Temperature
Triple Point
Visual
Berkelium is a Colorless. Bk has a CPK of #ffffff, Jmol of #8a4fe3, and MOLCAS GV of #8a4fe3. The Appearance of Element 97 is silvery.
Color	Colorless #ffffff #8a4fe3 #8a4fe3
Appearance	silvery
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
The lattice angles of Berkelium are π/2, π/2, 2 π/3.
Crystal Structure	Simple Hexagonal ()
Lattice Constant
Lattice Angles	π/2, π/2, 2 π/3
Mechanical Properties

Hardness
Bulk Modulus
Shear Modulus
Young Modulus
Poisson Ratio
Speed of Sound
Classification
The Glawe Number of Berkelium is 41. The Mendeleev Number of Bk is 30. The Pettifor Number of Element 97 is 40. The Goldschmidt Class of Berkelium (Bk) is synthetic.
Category	Actinides, Actinides
CAS Group
IUPAC Group
Glawe Number	41
Mendeleev Number	30
Pettifor Number	40
Geochemical Class
Goldschmidt Class	synthetic
Other
The Dipole Polarizability of Berkelium is 125 plus or minus 25 a₀. The Allotropes of Bk is . The Neutron Cross Section of Element 97 is 710. The Quantum Numbers of Berkelium (Bk) is 6H15/2. The Space Group of Berkelium is 194 (P63/mmc).
Gas Basicity
Dipole Polarizability	125 ± 25 a₀
C6 Dispersion Coefficient
Allotropes
Neutron Cross Section	710
Neutron Mass Absorption
Quantum Numbers	6H15/2
Space Group	194 (P63/mmc)

Isotopes of Berkelium

Stable Isotopes	0
Unstable Isotopes	22
Radioactive Isotopes	22

²³³Bk

Abundance	Radioactive ☢️
Relative Atomic Mass	233.056652 ± 0.00025 Da
Mass Number	233
G-Factor
Half Life	40 ± 30 s
Spin	3/2
Quadrupole Moment
Discovery Year	2015
Parity	-

²³³Bk Decay Modes

Decay Mode	Intensity
α (α emission)	82%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%

²³⁴Bk

Abundance	Radioactive ☢️
Relative Atomic Mass	234.057322 ± 0.000164 Da
Mass Number	234
G-Factor
Half Life	20 ± 5 s
Spin	3
Quadrupole Moment
Discovery Year	2003
Parity	-

²³⁴Bk Decay Modes

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

²³⁵Bk

Abundance	Radioactive ☢️
Relative Atomic Mass	235.056651 ± 0.00043 Da
Mass Number	235
G-Factor
Half Life
Spin	3/2
Quadrupole Moment
Discovery Year
Parity	-

²³⁵Bk Decay Modes

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

²³⁶Bk

Abundance	Radioactive ☢️
Relative Atomic Mass	236.057479 ± 0.000387 Da
Mass Number	236
G-Factor
Half Life	26 ± 10 s
Spin	4
Quadrupole Moment
Discovery Year	2017
Parity	+

²³⁶Bk Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
α (α emission)	%
β⁺ SF (β⁺-delayed fission)	0.04%

²³⁷Bk

Abundance	Radioactive ☢️
Relative Atomic Mass	237.057123 ± 0.000247 Da
Mass Number	237
G-Factor
Half Life
Spin	3/2
Quadrupole Moment
Discovery Year
Parity	-

²³⁷Bk Decay Modes

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

²³⁸Bk

Abundance	Radioactive ☢️
Relative Atomic Mass	238.058204 ± 0.000275 Da
Mass Number	238
G-Factor
Half Life	2.4 ± 0.08 m
Spin	1
Quadrupole Moment
Discovery Year	1994
Parity

²³⁸Bk Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
α (α emission)	%
β⁺ SF (β⁺-delayed fission)	0.048%

²³⁹Bk

Abundance	Radioactive ☢️
Relative Atomic Mass	239.058239 ± 0.000222 Da
Mass Number	239
G-Factor
Half Life
Spin	7/2
Quadrupole Moment
Discovery Year	1989
Parity	+

²³⁹Bk Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
α (α emission)	0.01%
SF (spontaneous fission)	0.01%

²⁴⁰Bk

Abundance	Radioactive ☢️
Relative Atomic Mass	240.059758 ± 0.000161 Da
Mass Number	240
G-Factor
Half Life	4.8 ± 0.8 m
Spin	7
Quadrupole Moment
Discovery Year	1980
Parity	-

²⁴⁰Bk Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%
α (α emission)	%
β⁺ SF (β⁺-delayed fission)	0.002%

²⁴¹Bk

Abundance	Radioactive ☢️
Relative Atomic Mass	241.060098 ± 0.000178 Da
Mass Number	241
G-Factor
Half Life	4.6 ± 0.4 m
Spin	7/2
Quadrupole Moment
Discovery Year	2003
Parity	+

²⁴¹Bk Decay Modes

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

²⁴²Bk

Abundance	Radioactive ☢️
Relative Atomic Mass	242.061999 ± 0.000144 Da
Mass Number	242
G-Factor
Half Life	7 ± 1.3 m
Spin	3
Quadrupole Moment
Discovery Year	1972
Parity	+

²⁴²Bk Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
β⁺ SF (β⁺-delayed fission)	3%
α (α emission)	%

²⁴³Bk

Abundance	Radioactive ☢️
Relative Atomic Mass	243.063005905 ± 0.000004856 Da
Mass Number	243
G-Factor
Half Life	4.6 ± 0.2 h
Spin	3/2
Quadrupole Moment
Discovery Year	1950
Parity	-

²⁴³Bk Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
α (α emission)	0.15%

²⁴⁴Bk

Abundance	Radioactive ☢️
Relative Atomic Mass	244.065178969 ± 0.000015457 Da
Mass Number	244
G-Factor
Half Life	5.02 ± 0.03 h
Spin	4
Quadrupole Moment
Discovery Year	1972
Parity	-

²⁴⁴Bk Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%
α (α emission)	0.006%

²⁴⁵Bk

Abundance	Radioactive ☢️
Relative Atomic Mass	245.066359814 ± 0.000001923 Da
Mass Number	245
G-Factor
Half Life	4.95 ± 0.03 d
Spin	3/2
Quadrupole Moment
Discovery Year	1951
Parity	-

²⁴⁵Bk Decay Modes

Decay Mode	Intensity
ϵ (electron capture)	99.88%
α (α emission)	0.12%

²⁴⁶Bk

Abundance	Radioactive ☢️
Relative Atomic Mass	246.0686713 ± 0.000064433 Da
Mass Number	246
G-Factor
Half Life	1.8 ± 0.02 d
Spin	2
Quadrupole Moment
Discovery Year	1954
Parity

²⁴⁶Bk Decay Modes

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

²⁴⁷Bk

Abundance	Radioactive ☢️
Relative Atomic Mass	247.070305889 ± 0.00000557 Da
Mass Number	247
G-Factor
Half Life	1.38 ± 0.25 ky
Spin	3/2
Quadrupole Moment
Discovery Year	1965
Parity	-

²⁴⁷Bk Decay Modes

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

²⁴⁸Bk

Abundance	Radioactive ☢️
Relative Atomic Mass	248.073141689 ± 0.000053739 Da
Mass Number	248
G-Factor
Half Life
Spin	6
Quadrupole Moment
Discovery Year	1956
Parity	+

²⁴⁸Bk Decay Modes

Decay Mode	Intensity
α (α emission)	%
ϵ (electron capture)	%

²⁴⁹Bk

Abundance	Radioactive ☢️
Relative Atomic Mass	249.074983118 ± 0.000001339 Da
Mass Number	249
G-Factor	0.57142857142857 ± 0.11428571428571
Half Life	327.2 ± 0.3 d
Spin	7/2
Quadrupole Moment
Discovery Year	1954
Parity	+

²⁴⁹Bk Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%
α (α emission)	0.00145%
SF (spontaneous fission)	47%

²⁵⁰Bk

Abundance	Radioactive ☢️
Relative Atomic Mass	250.078317195 ± 0.00000311 Da
Mass Number	250
G-Factor
Half Life	3.212 ± 0.005 h
Spin	2
Quadrupole Moment
Discovery Year	1954
Parity	-

²⁵⁰Bk Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

²⁵¹Bk

Abundance	Radioactive ☢️
Relative Atomic Mass	251.080760555 ± 0.000011523 Da
Mass Number	251
G-Factor
Half Life	55.6 ± 1.1 m
Spin	3/2
Quadrupole Moment
Discovery Year	1967
Parity	-

²⁵¹Bk Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

²⁵²Bk

Abundance	Radioactive ☢️
Relative Atomic Mass	252.08431 ± 0.000215 Da
Mass Number	252
G-Factor
Half Life	1.8 ± 0.5 m
Spin
Quadrupole Moment
Discovery Year	1988
Parity

²⁵²Bk Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	%
α (α emission)	%

²⁵³Bk

Abundance	Radioactive ☢️
Relative Atomic Mass	253.08688 ± 0.000385 Da
Mass Number	253
G-Factor
Half Life
Spin	3/2
Quadrupole Moment
Discovery Year	1991
Parity	-

²⁵³Bk Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	%

²⁵⁴Bk

Abundance	Radioactive ☢️
Relative Atomic Mass	254.0906 ± 0.00032 Da
Mass Number	254
G-Factor
Half Life
Spin
Quadrupole Moment
Discovery Year
Parity

²⁵⁴Bk Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	%

History

Berkelium was discovered by Glenn T. Seaborg, Albert Ghiorso and Stanley G. Thompson in 1949 at the University of California, Berkeley. It was produced by the bombardment of americium with alpha particles. Berkelium was isolated in greater quantities for the first time by Burris Cunningham and Stanley Thompson in 1958. Named after Berkeley, California, the city of its discovery

Discoverers	G.T.Seaborg, S.G.Tompson, A.Ghiorso
Discovery Location	United States
Discovery Year	1949
Etymology (Name Origin)	Named after Berkeley, California the city of its discovery.
Pronunciation	BURK-li-em (English)

Berkelium is harmful due to its radioactivity

Just over one gram of berkelium has been produced in the United States since 1967

Uses

Berkelium is mainly used for scientific research purposes. Berkelium-249 is a common target nuclide to prepare still heavier transuranic elements and transactinides, such as lawrencium, rutherfordium and bohrium. It is also useful as a source of the isotope californium-249. It has no significant commercial applications.

Sources

Some compounds have been made and studied. Made by bombarding americium with alpha particles.

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

Berkelium on ChemicalAid

Australian Educational Vocabulary ID	scot/2377
CAS Registry Number	7440-40-6
ChEBI ID	33391
ChemSpider ID	22409
DSSTOX compound identifier	DTXCID20147880
DSSTox substance ID	DTXSID70225389
Den Store Danske ID	berkelium
DrugBank ID	12993
Elhuyar ZTH ID	021522
Encyclopædia Britannica Online ID	science/berkelium
Encyclopædia Universalis ID	berkelium
Freebase ID	/m/025svnm
French Vikidia ID	Berkélium
GND ID	4511718-4
Gran Enciclopèdia Catalana ID	0223127
Great Russian Encyclopedia Online ID	1860452
InChI	InChI=1S/Bk
InChIKey	PWVKJRSRVJTHTR-UHFFFAOYSA-N
KBpedia ID	Berkelium
Library of Congress authority ID	sh2012004283
MeSH descriptor ID	D001603
NE.se ID	berkelium
National Library of Israel J9U ID	987007597623305171
OmegaWiki Defined Meaning	156441
Probes And Drugs ID	PD058313
PubChem CID	23971
Römpp online ID	RD-02-00987
Store norske leksikon ID	berkelium
Treccani ID	berkelio
UNII	2YQA718KUU
USGS Thesaurus ID	1405
WordNet 3.1 Synset ID	14655312-n

Berkelium (Bk)

Properties

Isotopes of Berkelium

233Bk

233Bk Decay Modes

234Bk

234Bk Decay Modes

235Bk

235Bk Decay Modes

236Bk

236Bk Decay Modes

237Bk

237Bk Decay Modes

238Bk

238Bk Decay Modes

239Bk

239Bk Decay Modes

240Bk

240Bk Decay Modes

241Bk

241Bk Decay Modes

242Bk

242Bk Decay Modes

243Bk

243Bk Decay Modes

244Bk

244Bk Decay Modes

245Bk

245Bk Decay Modes

246Bk

246Bk Decay Modes

247Bk

247Bk Decay Modes

248Bk

248Bk Decay Modes

249Bk

249Bk Decay Modes

250Bk

250Bk Decay Modes

251Bk

251Bk Decay Modes

252Bk

252Bk Decay Modes

253Bk

253Bk Decay Modes

254Bk

254Bk Decay Modes