Berkelium-238

Properties and data of the isotope ²³⁸Bk.

Content

General data

Name of the isotope:Berkelium-238; Bk-238Symbol:²³⁸Bk or 23897BkMass number A:238 (= number of nucleons)Atomic number Z:97 (= number of protons)Neutrons N:141Isotopic mass:238.05820(27) u (atomic weight of Berkelium-238)Nuclide mass:238.0049953 u (calculated nuclear mass without electrons)Mass excess:54.21295 MeVMass defect:1.92258126 u (per nucleus)Nuclear binding energy:1790.8729082 MeV (per nucleus)
7.52467608 MeV (average binding energy per nucleon)Separation energy:S_N = 7.04(34) MeV (first neutron)
S_P = 2.32(26) MeV (first proton)Half-life:144(5) sDecay constant λ:0.0048135220872218 s^-1Specific activity α:1.217970926120 × 10⁺¹⁹ Bq g^-1
329181331.38389 Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:1994

Radioactive Decay

Half-life T_½ = 144(5) s respectively 1.44 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EE/β⁺	²³⁸Cm	99.952 %	4.77(26) MeV
EE, F		0.048(20) %

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 141) and isobaric (same nucleon number A = 238) with Berkelium-238. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 141	Isobar A = 238
83	²²⁴Bi
84	²²⁵Po
85	²²⁶At
86	²²⁷Rn
87	²²⁸Fr
88	²²⁹Ra
89	²³⁰Ac
90	²³¹Th	²³⁸Th
91	²³²Pa	²³⁸Pa
92	²³³U	²³⁸U
93	²³⁴Np	²³⁸Np
94	²³⁵Pu	²³⁸Pu
95	²³⁶Am	²³⁸Am
96	²³⁷Cm	²³⁸Cm
97	²³⁸Bk	²³⁸Bk
98	²³⁹Cf	²³⁸Cf
99	²⁴⁰Es
100	²⁴¹Fm