Manganese-64m

Properties and data of the isotope ^64mMn.

Contents

Manganese-64m is an excited nuclear state of the nuclide ⁶⁴Mn, characterized by a defined excitation energy of 175.5 keV. Its spin and parity quantum numbers differ from those of the ground state (gs). Simultaneously, this metastable nuclear isomer possesses an independent, experimentally measurable lifetime: decay occurs via an isomeric transition to Mn-64 in the ground state with a half-life of approximately 0.440 seconds.

Manganese-64m was first described in the literature in 1998 [1].

See also: List of individual Manganese isotopes (and general data sources).

General data

Name of the isotope:Manganese-64m; Mn-64mSymbol:^64mMn or 64m25MnMass number A:64 (= number of nucleons)Atomic number Z:25 (= number of protons)Neutrons N:39Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.56 (= neutron-proton ratio)Neutron excess (N-Z):14Excitation energy:175.5(4) keVIsotopic mass:63.953849(4) u (atomic weight of Manganese-64m)Nuclide mass:63.9401348 u (calculated nuclear mass without electrons)Mass excess:-42.98938 MeVMass defect:0.579708524 u (per nucleus)Nuclear binding energy:539.99501185 MeV (per nucleus)
8.43742206 MeV (average binding energy per nucleon)Half-life:440(49) msDecay constant λ:1386.2943611199 s^-1Specific activity α:1.305388167873 × 10⁺²⁵ Bq g^-1
3.528076129388 × 10⁺¹⁴ Ci g^-1Spin and parity:
(nuclear angular momentum)(4+)Year of discovery:1998

Radioactive Decay

Half-life T_½ = 440(49) ms respectively 5.0 × 10^-4 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	⁶⁴Mn	100 %

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
⁶⁴Mn		90(4) ms	(1+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 39) and isobaric (same nucleon number A = 64) with Manganese-64m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 39	Isobar A = 64
19	⁵⁸K
21	⁶⁰Sc
22	⁶¹Ti	⁶⁴Ti
23	⁶²V	⁶⁴V
24	⁶³Cr	⁶⁴Cr
25	⁶⁴Mn	⁶⁴Mn
26	⁶⁵Fe	⁶⁴Fe
27	⁶⁶Co	⁶⁴Co
28	⁶⁷Ni	⁶⁴Ni
29	⁶⁸Cu	⁶⁴Cu
30	⁶⁹Zn	⁶⁴Zn
31	⁷⁰Ga	⁶⁴Ga
32	⁷¹Ge	⁶⁴Ge
33	⁷²As	⁶⁴As
34	⁷³Se	⁶⁴Se
35	⁷⁴Br
36	⁷⁵Kr
37	⁷⁶Rb
38	⁷⁷Sr
39	⁷⁸Y
40	⁷⁹Zr
42	⁸¹Mo