Berkelium-249m

Properties and data of the isotope ²⁴⁹Bk.

Content

General data

Name of the isotope:Berkelium-249m; Bk-249mSymbol:²⁴⁹Bk or 24997BkMass number A:249 (= number of nucleons)Atomic number Z:97 (= number of protons)Neutrons N:152Isotopic mass:249.0749832(13) u (atomic weight of Berkelium-249m)
Excitation energy: 8.777(14) keVNuclide mass:249.0217785 u (calculated nuclear mass without electrons)Mass excess:69.8464 MeVMass defect:2.001112136 u (per nucleus)Nuclear binding energy:1864.02394801 MeV (per nucleus)
7.48603995 MeV (average binding energy per nucleon)Half-life:0.3 msDecay constant λ:2310.4906018665 s^-1Specific activity α:5.587991911646 × 10⁺²⁴ Bq g^-1
1.510268084228 × 10⁺¹⁴ Ci g^-1Spin and parity:
(nuclear angular momentum)3/2-

Nuclear Isomers

Nuclear isomers or excited states with the activation energy in keV related to the ground state.

Nuclear Isomer	Excitation Energy	Half-life	Spin
²⁴⁹Bk		330(4) d	7/2+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 152) and isobaric (same nucleon number A = 249) with Berkelium-249m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 152	Isobar A = 249
94	²⁴⁶Pu
95	²⁴⁷Am	²⁴⁹Am
96	²⁴⁸Cm	²⁴⁹Cm
97	²⁴⁹Bk	²⁴⁹Bk
98	²⁵⁰Cf	²⁴⁹Cf
99	²⁵¹Es	²⁴⁹Es
100	²⁵²Fm	²⁴⁹Fm
101	²⁵³Md	²⁴⁹Md
102	²⁵⁴No
103	²⁵⁵Lr
104	²⁵⁶Rf
105	²⁵⁷Db
106	²⁵⁸Sg