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Isotopes of manganese

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Isotopes of manganese (25Mn)
Main isotopes[1] Decay
abun­dance half-life (t1/2) mode pro­duct
52Mn synth 5.591 d β+ 52Cr
53Mn trace 3.7×106 y ε 53Cr
54Mn synth 312.081 d ε 54Cr
β− 54Fe
β+ 54Cr
55Mn 100% stable
Standard atomic weight Ar°(Mn)

Naturally occurring manganese (25Mn) is composed of one stable isotope, 55Mn. Twenty-seven radioisotopes have been characterized, with the most stable being 53Mn with a half-life of 3.7 million years, 54Mn with a half-life of 312.3 days, and 52Mn with a half-life of 5.591 days. All of the remaining radioactive isotopes have half-lives that are less than 3 hours and the majority of these have half-lives that are less than a minute. This element also has seven meta states.

Manganese is part of the iron group of elements, which are thought to be synthesized in large stars shortly before supernova explosions. 53Mn decays to 53Cr with a half-life of 3.7 million years. Because of its relatively short half-life, 53Mn occurs only in tiny amounts due to the action of cosmic rays on iron in rocks.[4] Manganese isotopic contents are typically combined with chromium isotopic contents and have found application in isotope geology and radiometric dating. Mn−Cr isotopic ratios reinforce the evidence from 26Al and 107Pd for the early history of the Solar System. Variations in 53Cr/52Cr and Mn/Cr ratios from several meteorites indicate an initial 53Mn/55Mn ratio that suggests Mn−Cr isotopic systematics must result from in-situ decay of 53Mn in differentiated planetary bodies. Hence 53Mn provides additional evidence for nucleosynthetic processes immediately before coalescence of the Solar System.

The isotopes of manganese range from 46Mn to 73Mn. The primary decay mode before the most abundant stable isotope, 55Mn, is electron capture and the primary mode after is beta decay.

List of isotopes

[edit]
Nuclide
[n 1] 		Z N Isotopic mass (Da)
[n 2][n 3] 		Half-life
 Decay
mode
[n 4] 		Daughter
isotope
[n 5] 		Spin and
parity
[n 6][n 7] 		Isotopic
abundance
Excitation energy[n 7]
46Mn 25 21 45.986669(93) 36.2(4) ms β+, p (57.0%) 45V (4+)
β+ (25%) 46Cr
β+, 2p (18%) 44Ti
β+, α? 42Ti
47Mn 25 22 46.975774(34) 88.0(13) ms β+ 47Cr 5/2−#
β+, p? (<1.7%) 46V
48Mn 25 23 47.9685488(72) 158.1(22) ms β+ (99.72%) 48Cr 4+
β+, p (0.28%) 47V
β+, α (6×10−4%) 44Ti
49Mn 25 24 48.9596134(24) 382(7) ms β+ 49Cr 5/2−
50Mn 25 25 49.95423816(12) 283.21(7) ms β+ 50Cr 0+
50mMn 225.31(7) keV 1.75(3) min β+ 50Cr 5+
51Mn 25 26 50.94820877(33) 45.81(21) min β+ 51Cr 5/2−
52Mn 25 27 51.94555909(14) 5.591(3) d β+ 52Cr 6+
52mMn 377.749(5) keV 21.1(2) min β+ (98.22%) 52Cr 2+
IT (1.78%) 52Mn
53Mn 25 28 52.94128750(37) 3.7(4)×106 y EC 53Cr 7/2− trace
54Mn 25 29 53.9403558(11) 312.081(32) d EC 54Cr 3+
β− (9.3×10−5%) 54Fe
β+ (1.28×10−7%) 54Cr
55Mn 25 30 54.93804304(28) Stable 5/2− 1.0000
56Mn 25 31 55.93890282(31) 2.5789(1) h β− 56Fe 3+
57Mn 25 32 56.9382859(16) 85.4(18) s β− 57Fe 5/2−
58Mn 25 33 57.9400666(29) 3.0(1) s β− 58Fe 1+
58mMn 71.77(5) keV 65.4(5) s β− 58Fe 4+
IT? 58Mn
59Mn 25 34 58.9403911(25) 4.59(5) s β− 59Fe 5/2−
60Mn 25 35 59.9431366(25) 280(20) ms β− 60Fe 1+
60mMn 271.90(10) keV 1.77(2) s β− (88.5%) 60Fe 4+
IT (11.5%) 60Mn
61Mn 25 36 60.9444525(25) 709(8) ms β− 61Fe 5/2−
β−, n? 60Fe
62Mn 25 37 61.9479074(70) 92(13) ms β− 62Fe 1+
β−, n? 61Fe
62mMn[n 8] 343(6) keV 671(5) ms β− 62Fe 4+
β−, n? 61Fe
IT? 61Mn
63Mn 25 38 62.9496647(40) 275(4) ms β− 63Fe 5/2−
β−, n? 62Fe
64Mn 25 39 63.9538494(38) 88.8(24) ms β− (97.3%) 64Fe 1+
β−, n (2.7%) 63Fe
64mMn 174.1(5) keV 439(31) μs IT 64Mn (4+)
65Mn 25 40 64.9560197(40) 91.9(7) ms β− (92.1%) 65Fe (5/2−)
β−, n (7.9%) 64Fe
66Mn 25 41 65.960547(12) 63.8(9) ms β− (92.6%) 66Fe (1+)
β−, n (7.4%) 65Fe
β−, 2n? 64Fe
66mMn 464.5(4) keV 780(40) μs IT 66Mn (5−)
β−? 66Fe
67Mn 25 42 66.96395(22)# 46.7(23) ms β− (90%) 67Fe 5/2−#
β−, n (10%) 66Fe
β−, 2n? 65Fe
68Mn 25 43 67.96895(32)# 33.7(15) ms β− (82%) 68Fe (3)
β−, n (18%) 67Fe
β−, 2n? 66Fe
69Mn 25 44 68.97278(43)# 22.1(16) ms β− (60%) 69Fe 5/2−#
β−, n (40%) 68Fe
β−, 2n? 67Fe
70Mn 25 45 69.97805(54)# 19.9(17) ms β− 70Fe (4,5)
β−, n? 69Fe
β−, 2n? 68Fe
71Mn 25 46 70.98216(54)# 16# ms
[>400 ns] 		β−? 71Fe 5/2-#
β−, n? 70Fe
β−, 2n? 69Fe
72Mn 25 47 71.98801(64)# 12# ms
[>620 ns] 		β−? 72Fe
β−, n? 71Fe
β−, 2n? 70Fe
73Mn 25 48 72.99281(64)# 12# ms
[>410 ns] 		β−? 73Fe 5/2−#
This table header & footer:
  1. ^ mMn – Excited nuclear isomer.
  2. ^ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  3. ^ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
  4. ^ Modes of decay:
    EC: Electron capture
    IT: Isomeric transition
    n: Neutron emission
    p: Proton emission
  5. ^ Bold symbol as daughter – Daughter product is stable.
  6. ^ ( ) spin value – Indicates spin with weak assignment arguments.
  7. ^ a b # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
  8. ^ Order of ground state and isomer is uncertain.

References

[edit]
  1. ^ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  2. ^ "Standard Atomic Weights: Manganese". CIAAW. 2017.
  3. ^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
  4. ^ J. Schaefer; et al. (2006). "Terrestrial manganese-53 — A new monitor of Earth surface processes". Earth and Planetary Science Letters. 251 (3–4): 334–345. Bibcode:2006E&PSL.251..334S. doi:10.1016/j.epsl.2006.09.016.
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