Berkelium is a transuranic radioactive chemical element with the major isotope 249Bk, synthesised in dedicated high-flux nuclear reactors. The production of the second-important isotope 247Bk involves the irradiation of the rare isotope 244Cm with high-energy alpha particles.

1949 by Glenn T. Seaborg, Stanley G. Thompson and Albert Ghiorso, USA.

DISCOVERY

From the name Berkeley, California, USA.

ETYMOLOGY

Berkelium

Element

Bk

Symbol

97

97 Atomic Number

Atomic Number

Actinide

Classification

7440-40-6

CAS Number

-

Elemental Colour

-

Refractive Index

-

Poisson Ratio

16.784 cm³

Molar Volume

-

Brinell Hardness

-

Mohs Hardness

-

Vickers Hardness

-

Speed of Sound

-

Bulk Modulus

-

Shear Modulus

-

Young Modulus

Allotropes

1,323.15 K, 1,050.00 °C

1,050.00 °C

Melting Point

-

Boiling Point

-

Automatic Ignition

-

Flashpoint

-

Critical Temperature

-

Critical Pressure

10.000'000 W/(m K)

Thermal Conductivity

-

Thermal Expansion

-

Specific Heat

-

Heat Fusion

-

Heat Vaporisation

-

Heat Combustion

-

Curie Point

-

Neel Point

-

Adiabatic Index

Solid

Phase

-

Electrical Type

-

Conductivity

-

Resistivity

-

Superconducting Point

-

Magnetic Type

-

Mass Susceptibility

-

Molar Susceptibility

-

Volume Susceptibility

Material Composition

-

Universe

-

Meteorites

-

Sun

-

Earth Crust

-

Oceans

-

Humans

248.072'647'5

Atomic Weight

-

Atomic Radius

168 pm

Covalent Radius Single Bond

139 pm

Covalent Radius Double Bond

-

Covalent Radius Triple Bond

244 pm

Van der Waals Radius

[Rn]7s²5f⁹

Electron Configuration

Hexagonal, Close Packed Double

Crystal Structure

14.780'00 g/cm³

Density as Solid

-

Density as Liquid

-

Density as Gas

P6₃/mmc

Space Group Name

194

194 Space Group Number

Space Group Number

π/2, π/2 & 2π/3

Lattice Angles

341.6, 341.6 & 1106.9 pm

Lattice Constants

1,379 years

Half Life

1,991 years

Lifetime

5f⁹ = 5, 3, -2, -1/2

Quantum Numbers

-

Neutron Cross Section

-

Neutron Mass Absorption

Stable Isotopes

NONE

Unstable Isotopes

Isotopes Overview

Isotope	Stability	Symbol	Type	Protons		Neutrons		Spin	Parity	Mass		Abundance		Mass Measure	Mass Excess		Binding Energy		Dipole Moment		Quadrupole Moment	Halflife in Years		Halflife in Seconds		A01 Decay Probability		A01 Decay Mode	A01 Decay Energy		A01 Decay Daughter	A01 Decay Link	A02 Decay Mode	A02 Decay Energy		A02 Decay Daughter	A02 Decay Link	A03 Decay Probability		A03 Decay Mode	A03 Decay Energy		A03 Decay Daughter	A03 Decay Link	Y01 Decay Product Yield		Y01 Decay Product Nuclide	Y02 Decay Product Yield		Y02 Decay Product Nuclide	Y03 Decay Product Yield		Y03 Decay Product Nuclide	Y04 Decay Product Yield		Y04 Decay Product Nuclide	Y05 Decay Product Yield		Y05 Decay Product Nuclide	Y06 Decay Product Yield		Y06 Decay Product Nuclide	Y07 Decay Product Yield		Y07 Decay Product Nuclide	Y08 Decay Product Yield		Y08 Decay Product Nuclide	Y09 Decay Product Yield		Y09 Decay Product Nuclide	Y10 Decay Product Yield		Y10 Decay Product Nuclide	Y11 Decay Product Yield		Y11 Decay Product Nuclide	Y12 Decay Product Yield		Y12 Decay Product Nuclide
Isotope_097_bk_235_u	Unstable	²³⁵Bk	Boson	97	p	138	n	?	0	235.056'580'000'0	u	~ 0	%	~ 0	79.056'000'000'0	MeV	7.460'7.460'7.460'7.460	MeV	-		-	6.34E-7	year	20.000	seconds ( x⁰ )	?	%	β+	3,772.000	keV	²³⁵Cm	²³⁵Bk > [ ? % , β+ , 3,772.0 keV ] > ²³⁵Cm	α	7,840.000	keV	²³¹Am	²³⁵Bk > [ , α , 7,840.0 keV ] > ²³¹Am								?	%	²⁰⁵Tl	?	%	²⁰⁸Pb	?	%	²⁰⁷Pb
Isotope_097_bk_236_u	Unstable	²³⁶Bk	Fermion	97	p	139	n	?	0	236.057'330'000'0	u	~ 0	%	~ 0	52.704'000'000'0	MeV	7.524'000'000'0	MeV	-		-	1.90E-6	year	60.000	seconds ( x⁰ )	?	%	β+	4,490.000	keV	²³⁶Cm	²³⁶Bk > [ ? % , β+ , 4,490.0 keV ] > ²³⁶Cm	α	7,579.000	keV	²³²Am	²³⁶Bk > [ , α , 7,579.0 keV ] > ²³²Am								?	%	²⁰⁸Pb	?	%	²⁰⁶Pb	?	%	²⁰⁰Hg	?	%	²⁰⁶Pb
Isotope_097_bk_237_u	Unstable	²³⁷Bk	Boson	97	p	140	n	7/2	1	237.057'003'000'0	u	~ 0	%	~ 0	53.403'000'000'0	MeV	7.523'000'000'0	MeV	-		-	1.90E-6	year	60.000	seconds ( x⁰ )	?	%	β+	2,779.000	keV	²³⁷Cm	²³⁷Bk > [ ? % , β+ , 2,779.0 keV ] > ²³⁷Cm	α	7,500.000	keV	²³³Am	²³⁷Bk > [ , α , 7,500.0 keV ] > ²³³Am								?	%	²⁰⁵Tl	?	%	²⁰⁷Pb
Isotope_097_bk_238_u	Unstable	²³⁸Bk	Fermion	97	p	141	n	?	0	238.058'281'000'0	u	~ 0	%	~ 0	53.098'000'000'0	MeV	7.527'000'000'0	MeV	-		-	4.44E-6	year	139.980	seconds ( x⁰ )	100.000'000	%	β+	3,871.000	keV	²³⁸Cm	²³⁸Bk > [ 100 % , β+ , 3,871.0 keV ] > ²³⁸Cm	β+SF	?	keV	V	²³⁸Bk > [ , β+SF , ? keV ] > V	?	%	α	7,330.000	keV	²³⁴Am	²³⁸Bk > [ ? % , α , 7,330.0 keV ] > ²³⁴Am	100.043'985	%	²⁰⁶Pb	0.000'002	%	²⁰⁵Tl	0.000'000	%	²⁰⁸Pb
Isotope_097_bk_239_u	Unstable	²³⁹Bk	Boson	97	p	142	n	7/2	1	239.058'279'000'0	u	~ 0	%	~ 0	54.288'000'000'0	MeV	7.524'000'000'0	MeV	-		-	6.33E-6	year	199.800	seconds ( x⁰ )	?	%	β+	2,073.000	keV	²³⁹Cm	²³⁹Bk > [ ? % , β+ , 2,073.0 keV ] > ²³⁹Cm	α	7,200.000	keV	²³⁵Am	²³⁹Bk > [ , α , 7,200.0 keV ] > ²³⁵Am								?	%	²⁰⁵Tl	?	%	²⁰⁸Pb	?	%	²⁰⁷Pb	0.000'000	%	¹⁶⁰Dy	0.000'000	%	¹⁴⁰Ce	?	%	¹⁷²Yb	?	%	¹⁷⁶Hf	?	%	¹⁵²Sm	?	%	¹⁸⁰Hf	?	%	¹⁵⁶Gd	?	%	¹⁶⁸Er	?	%	¹⁶⁴Dy
Isotope_097_bk_240_u	Unstable	²⁴⁰Bk	Fermion	97	p	143	n	?	0	240.059'759'000'0	u	~ 0	%	~ 0	54.287'000'000'0	MeV	7.527'000'000'0	MeV	-		-	9.19E-6	year	289.980	seconds ( x⁰ )	10.000'000	%	α	7,058.000	keV	²³⁶Am	²⁴⁰Bk > [ 10 % , α , 7,058.0 keV ] > ²³⁶Am	β+SF	?	keV	V	²⁴⁰Bk > [ , β+SF , ? keV ] > V								?	%	²⁰⁸Pb	?	%	²⁰⁶Pb	?	%	²⁰⁰Hg	?	%	²⁰⁶Pb
Isotope_097_bk_241_u	Unstable	²⁴¹Bk	Boson	97	p	144	n	7/2	1	241.060'230'000'0	u	~ 0	%	~ 0	55.665'000'000'0	MeV	7.523'000'000'0	MeV	-		-	8.87E-6	year	280.020	seconds ( x⁰ )	?	%	α	7,108.000	keV	²³⁷Am	²⁴¹Bk > [ ? % , α , 7,108.0 keV ] > ²³⁷Am	β+	1,378.000	keV	²⁴¹Cm	²⁴¹Bk > [ , β+ , 1,378.0 keV ] > ²⁴¹Cm								?	%	²⁰⁵Tl	?	%	²⁰⁷Pb
Isotope_097_bk_242_u	Unstable	²⁴²Bk	Fermion	97	p	145	n	2	-1	242.061'981'000'0	u	~ 0	%	~ 0	56.103'000'000'0	MeV	7.524'000'000'0	MeV	-		-	2.22E-7	year	7.000	seconds ( x⁰ )	100.000'000	%	β+	1,908.000	keV	²⁴²Cm	²⁴²Bk > [ 100 % , β+ , 1,908.0 keV ] > ²⁴²Cm	β+SF	?	keV	V	²⁴²Bk > [ , β+SF , ? keV ] > V	?	%	α	6,887.000	keV	²³⁸Am	²⁴²Bk > [ ? % , α , 6,887.0 keV ] > ²³⁸Am	100.044'159	%	²⁰⁶Pb	0.000'002	%	²⁰⁵Tl	0.000'000	%	²⁰⁸Pb
Isotope_097_bk_243_u	Unstable	²⁴³Bk	Boson	97	p	146	n	3/2	-1	243.063'007'572'0	u	~ 0	%	~ 0	57.735'000'000'0	MeV	7.519'000'000'0	MeV	-		-	5.07E-4	year	15.984	kilo-seconds ( x³ )	100.000'000	%	β+	485.380	keV	²⁴³Am	²⁴³Bk > [ 100 % , β+ , 485.38 keV ] > ²⁴³Am	α	6,874.280	keV	²³⁹Am	²⁴³Bk > [ , α , 6,874.28 keV ] > ²³⁹Am								100.717'544	%	²⁰⁷Pb	0.000'000	%	²⁰⁵Tl	0.000'000	%	²⁰⁶Pb	0.000'000	%	¹⁶⁰Dy	0.000'000	%	¹⁴⁰Ce	?	%	¹⁷²Yb	?	%	¹⁷⁶Hf	?	%	¹⁵²Sm	?	%	¹⁸⁰Hf	?	%	¹⁵⁶Gd	?	%	¹⁶⁸Er	?	%	¹⁶⁴Dy
Isotope_097_bk_244_u	Unstable	²⁴⁴Bk	Fermion	97	p	147	n	4	-1	244.065'180'774'0	u	~ 0	%	~ 0	58.691'176'000'0	MeV	7.517'495'000'0	MeV	-		-	4.97E-4	year	15.700	kilo-seconds ( x³ )	99.994'000	%	β+	1,239.700	keV	²⁴⁴Cm	²⁴⁴Bk > [ 99.994 % , β+ , 1,239.7 keV ] > ²⁴⁴Cm	α	6,778.800	keV	²⁴⁰Am	²⁴⁴Bk > [ , α , 6,778.8 keV ] > ²⁴⁰Am								100.004'000	%	²⁰⁸Pb	0.000'000	%	²⁰⁶Pb	?	%	²⁰⁰Hg	0.000'000	%	²⁰⁸Pb
Isotope_097_bk_245_u	Unstable	²⁴⁵Bk	Boson	97	p	148	n	3/2	-1	245.066'361'616'0	u	~ 0	%	~ 0	60.715'501'000'0	MeV	7.511'468'000'0	MeV	-		-	1.35E-2	year	426.989	kilo-seconds ( x³ )	100.000'000	%	ϵ	810.740	keV	²⁴⁵Cm	²⁴⁵Bk > [ 100 % , ϵ , 810.74 keV ] > ²⁴⁵Cm	α	6,454.520	keV	²⁴¹Am	²⁴⁵Bk > [ , α , 6,454.52 keV ] > ²⁴¹Am								100.135'266	%	²⁰⁵Tl	0.000'000	%	²⁰⁷Pb
Isotope_097_bk_246_u	Unstable	²⁴⁶Bk	Fermion	97	p	149	n	2	-1	246.068'672'947'0	u	~ 0	%	~ 0	61.815'448'000'0	MeV	7.509'264'000'0	MeV	-		-	5.07E-3	year	159.840	kilo-seconds ( x³ )	100.000'000	%	β+	327.800	keV	²⁴⁶Cm	²⁴⁶Bk > [ 100 % , β+ , 327.8 keV ] > ²⁴⁶Cm	α	6,073.800	keV	²⁴²Am	²⁴⁶Bk > [ , α , 6,073.8 keV ] > ²⁴²Am								100.144'203	%	²⁰⁶Pb	0.000'002	%	²⁰⁵Tl	0.000'000	%	²⁰⁸Pb
Isotope_097_bk_247_u	Unstable	²⁴⁷Bk	Boson	97	p	150	n	3/2	1	247.070'307'080'0	u	~ 0	%	~ 0	63.968'439'000'0	MeV	7.502'797'000'0	MeV	-		-	1.38E+3	years	43.518	giga-seconds ( x⁹ )	100.000'000	%	α	5,889.600	keV	²⁴³Am	²⁴⁷Bk > [ 100 % , α , 5,889.6 keV ] > ²⁴³Am	SF	?	keV	V	²⁴⁷Bk > [ , SF , ? keV ] > V								100.276'314	%	²⁰⁷Pb	0.000'000	%	²⁰⁵Tl	0.000'000	%	²⁰⁶Pb	0.000'000	%	¹⁶⁰Dy	0.000'000	%	¹⁴⁰Ce	?	%	¹⁷²Yb	?	%	¹⁷⁶Hf	?	%	¹⁵²Sm	?	%	¹⁸⁰Hf	?	%	¹⁵⁶Gd	?	%	¹⁶⁸Er	?	%	¹⁶⁴Dy
Isotope_097_bk_248_u	Unstable	²⁴⁸Bk	Fermion	97	p	151	n	6	1	248.073'086'000'0	u	~ 0	%	~ 0	65.490'624'000'0	MeV	7.498'936'000'0	MeV	-		-	9.51E+0	years	300.113	mega-seconds ( x⁶ )	?	%	α	5,774.000	keV	²⁴⁴Am	²⁴⁸Bk > [ ? % , α , 5,774.0 keV ] > ²⁴⁴Am													?	%	²⁰⁸Pb	?	%	²⁰⁶Pb	?	%	²⁰⁰Hg	0.000'000	%	²⁰⁸Pb
Isotope_097_bk_249_u	Unstable	²⁴⁹Bk	Boson	97	p	152	n	7/2	1	249.074'986'657'0	u	~ 0	%	~ 0	68.080'000'000'0	MeV	7.491'000'000'0	MeV	2.000'000'000'0	nm	-	9.31E-1	year	29.371	mega-seconds ( x⁶ )	100.000'000	%	β-	124.000	keV	²⁴⁹Cf	²⁴⁹Bk > [ 100 % , β- , 124.0 keV ] > ²⁴⁹Cf	α	5,524.960	keV	²⁴⁵Am	²⁴⁹Bk > [ , α , 5,524.96 keV ] > ²⁴⁵Am	0.000'000	%	SF	?	keV	V	²⁴⁹Bk > [ 0.000000047 % , SF , ? keV ] > V	100.016'701	%	²⁰⁵Tl	0.000'000	%	²⁰⁷Pb
Isotope_097_bk_250_u	Unstable	²⁵⁰Bk	Fermion	97	p	153	n	2	-1	250.078'316'520'0	u	~ 0	%	~ 0	69.849'622'000'0	MeV	7.486'027'000'0	MeV	-		-	3.66E-4	year	11.560	kilo-seconds ( x³ )	100.000'000	%	β-	1,779.580	keV	²⁵⁰Cf	²⁵⁰Bk > [ 100 % , β- , 1,779.58 keV ] > ²⁵⁰Cf													100.044'159	%	²⁰⁶Pb	0.000'002	%	²⁰⁵Tl	0.000'000	%	²⁰⁸Pb
Isotope_097_bk_251_u	Unstable	²⁵¹Bk	Boson	97	p	154	n	3/2	-1	251.080'760'172'0	u	~ 0	%	~ 0	72.951'370'000'0	MeV	7.475'961'000'0	MeV	-		-	1.06E-4	year	3.340	kilo-seconds ( x³ )	100.000'000	%	β-	1,093.000	keV	²⁵¹Cf	²⁵¹Bk > [ 100 % , β- , 1,093.0 keV ] > ²⁵¹Cf													100.276'314	%	²⁰⁷Pb	0.000'000	%	²⁰⁵Tl	0.000'000	%	²⁰⁶Pb	0.000'000	%	¹⁶⁰Dy	0.000'000	%	¹⁴⁰Ce	?	%	¹⁷²Yb	?	%	¹⁷⁶Hf	?	%	¹⁵²Sm	?	%	¹⁸⁰Hf	?	%	¹⁵⁶Gd	?	%	¹⁶⁸Er	?	%	¹⁶⁴Dy
Isotope_097_bk_252_u	Unstable	²⁵²Bk	Fermion	97	p	155	n	?	0	252.084'310'000'0	u	~ 0	%	~ 0	75.227'617'000'0	MeV	7.469'264'000'0	MeV	-		-	3.49E-6	year	109.980	seconds ( x⁰ )	?	%	β-	2,500.000	keV	²⁵²Cf	²⁵²Bk > [ ? % , β- , 2,500.0 keV ] > ²⁵²Cf	α	5,547.000	keV	²⁴⁸Am	²⁵²Bk > [ , α , 5,547.0 keV ] > ²⁴⁸Am								?	%	²⁰⁸Pb	?	%	²⁰⁶Pb	?	%	²⁰⁰Hg	0.000'000	%	²⁰⁸Pb
Isotope_097_bk_253_u	Unstable	²⁵³Bk	Boson	97	p	156	n	?	0	253.086'880'000'0	u	~ 0	%	~ 0	78.534'000'000'0	MeV	7.459'000'000'0	MeV	-		-	1.90E-5	year	600.000	seconds ( x⁰ )	?	%	β-	1,628.000	keV	²⁵³Cf	²⁵³Bk > [ ? % , β- , 1,628.0 keV ] > ²⁵³Cf													?	%	²⁰⁵Tl	?	%	²⁰⁷Pb
Isotope_097_bk_254_u	Unstable	²⁵⁴Bk	Fermion	97	p	157	n	?	0	254.090'600'000'0	u	~ 0	%	~ 0	80.929'000'000'0	MeV	7.451'000'000'0	MeV	-		-	1.90E-6	year	60.000	seconds ( x⁰ )	?	%	β-	3,053.000	keV	²⁵⁴Cf	²⁵⁴Bk > [ ? % , β- , 3,053.0 keV ] > ²⁵⁴Cf													?	%	¹⁷²Yb	?	%	²⁰⁵Tl	?	%	²⁰⁸Pb

97 – Berkelium, Bk

97 – Berkelium, Bk

97 – Berkelium, Bk

97 – Berkelium, Bk

97 – Berkelium, Bk

Spectrograph

Elemental Tile

Berkelium

Spectrograph

Elemental Tile

Berkelium

Spectrograph

Elemental Tile

Berkelium

Spectrograph

Elemental Tile

Berkelium

Spectrograph

Elemental Tile

Berkelium