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Standard atomic weight Ar°(Mn) | |||||||||||||||||||||||||||||||||||
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Naturally occurring manganese (25Mn) is composed of one stable isotope, Mn. Twenty-seven radioisotopes have been characterized, with the most stable being Mn with a half-life of 3.7 million years, Mn with a half-life of 312.3 days, and Mn 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. Mn decays to Cr with a half-life of 3.7 million years. Because of its relatively short half-life, Mn occurs only in tiny amounts due to the action of cosmic rays on iron in rocks. 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 Al and Pd for the early history of the Solar System. Variations in Cr/Cr and Mn/Cr ratios from several meteorites indicate an initial Mn/Mn ratio that suggests Mn−Cr isotopic systematics must result from in-situ decay of Mn in differentiated planetary bodies. Hence Mn provides additional evidence for nucleosynthetic processes immediately before coalescence of the Solar System.
The isotopes of manganese range from Mn to Mn. The primary decay mode before the most abundant stable isotope, Mn, is electron capture and the primary mode after is beta decay.
List of isotopes
Nuclide |
Z | N | Isotopic mass (Da) |
Half-life |
Decay mode |
Daughter isotope |
Spin and parity |
Isotopic abundance | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Excitation energy | |||||||||||||||||||
Mn | 25 | 21 | 45.986669(93) | 36.2(4) ms | β, p (57.0%) | V | (4+) | ||||||||||||
β (25%) | Cr | ||||||||||||||||||
β, 2p (18%) | Ti | ||||||||||||||||||
β, α? | Ti | ||||||||||||||||||
Mn | 25 | 22 | 46.975774(34) | 88.0(13) ms | β | Cr | 5/2−# | ||||||||||||
β, p? (<1.7%) | V | ||||||||||||||||||
Mn | 25 | 23 | 47.9685488(72) | 158.1(22) ms | β (99.72%) | Cr | 4+ | ||||||||||||
β, p (0.28%) | V | ||||||||||||||||||
β, α (6×10%) | Ti | ||||||||||||||||||
Mn | 25 | 24 | 48.9596134(24) | 382(7) ms | β | Cr | 5/2− | ||||||||||||
Mn | 25 | 25 | 49.95423816(12) | 283.21(7) ms | β | Cr | 0+ | ||||||||||||
Mn | 225.31(7) keV | 1.75(3) min | β | Cr | 5+ | ||||||||||||||
Mn | 25 | 26 | 50.94820877(33) | 45.81(21) min | β | Cr | 5/2− | ||||||||||||
Mn | 25 | 27 | 51.94555909(14) | 5.591(3) d | β | Cr | 6+ | ||||||||||||
Mn | 377.749(5) keV | 21.1(2) min | β (98.22%) | Cr | 2+ | ||||||||||||||
IT (1.78%) | Mn | ||||||||||||||||||
Mn | 25 | 28 | 52.94128750(37) | 3.7(4)×10 y | EC | Cr | 7/2− | trace | |||||||||||
Mn | 25 | 29 | 53.9403558(11) | 312.081(32) d | EC | Cr | 3+ | ||||||||||||
β (9.3×10%) | Fe | ||||||||||||||||||
β (1.28×10%) | Cr | ||||||||||||||||||
Mn | 25 | 30 | 54.93804304(28) | Stable | 5/2− | 1.0000 | |||||||||||||
Mn | 25 | 31 | 55.93890282(31) | 2.5789(1) h | β | Fe | 3+ | ||||||||||||
Mn | 25 | 32 | 56.9382859(16) | 85.4(18) s | β | Fe | 5/2− | ||||||||||||
Mn | 25 | 33 | 57.9400666(29) | 3.0(1) s | β | Fe | 1+ | ||||||||||||
Mn | 71.77(5) keV | 65.4(5) s | β | Fe | 4+ | ||||||||||||||
IT? | Mn | ||||||||||||||||||
Mn | 25 | 34 | 58.9403911(25) | 4.59(5) s | β | Fe | 5/2− | ||||||||||||
Mn | 25 | 35 | 59.9431366(25) | 280(20) ms | β | Fe | 1+ | ||||||||||||
Mn | 271.90(10) keV | 1.77(2) s | β (88.5%) | Fe | 4+ | ||||||||||||||
IT (11.5%) | Mn | ||||||||||||||||||
Mn | 25 | 36 | 60.9444525(25) | 709(8) ms | β | Fe | 5/2− | ||||||||||||
β, n? | Fe | ||||||||||||||||||
Mn | 25 | 37 | 61.9479074(70) | 92(13) ms | β | Fe | 1+ | ||||||||||||
β, n? | Fe | ||||||||||||||||||
Mn | 343(6) keV | 671(5) ms | β | Fe | 4+ | ||||||||||||||
β, n? | Fe | ||||||||||||||||||
IT? | Mn | ||||||||||||||||||
Mn | 25 | 38 | 62.9496647(40) | 275(4) ms | β | Fe | 5/2− | ||||||||||||
β, n? | Fe | ||||||||||||||||||
Mn | 25 | 39 | 63.9538494(38) | 88.8(24) ms | β (97.3%) | Fe | 1+ | ||||||||||||
β, n (2.7%) | Fe | ||||||||||||||||||
Mn | 174.1(5) keV | 439(31) μs | IT | Mn | (4+) | ||||||||||||||
Mn | 25 | 40 | 64.9560197(40) | 91.9(7) ms | β (92.1%) | Fe | (5/2−) | ||||||||||||
β, n (7.9%) | Fe | ||||||||||||||||||
Mn | 25 | 41 | 65.960547(12) | 63.8(9) ms | β (92.6%) | Fe | (1+) | ||||||||||||
β, n (7.4%) | Fe | ||||||||||||||||||
β, 2n? | Fe | ||||||||||||||||||
Mn | 464.5(4) keV | 780(40) μs | IT | Mn | (5−) | ||||||||||||||
β? | Fe | ||||||||||||||||||
Mn | 25 | 42 | 66.96395(22)# | 46.7(23) ms | β (90%) | Fe | 5/2−# | ||||||||||||
β, n (10%) | Fe | ||||||||||||||||||
β, 2n? | Fe | ||||||||||||||||||
Mn | 25 | 43 | 67.96895(32)# | 33.7(15) ms | β (82%) | Fe | (3) | ||||||||||||
β, n (18%) | Fe | ||||||||||||||||||
β, 2n? | Fe | ||||||||||||||||||
Mn | 25 | 44 | 68.97278(43)# | 22.1(16) ms | β (60%) | Fe | 5/2−# | ||||||||||||
β, n (40%) | Fe | ||||||||||||||||||
β, 2n? | Fe | ||||||||||||||||||
Mn | 25 | 45 | 69.97805(54)# | 19.9(17) ms | β | Fe | (4,5) | ||||||||||||
β, n? | Fe | ||||||||||||||||||
β, 2n? | Fe | ||||||||||||||||||
Mn | 25 | 46 | 70.98216(54)# | 16# ms |
β? | Fe | 5/2-# | ||||||||||||
β, n? | Fe | ||||||||||||||||||
β, 2n? | Fe | ||||||||||||||||||
Mn | 25 | 47 | 71.98801(64)# | 12# ms |
β? | Fe | |||||||||||||
β, n? | Fe | ||||||||||||||||||
β, 2n? | Fe | ||||||||||||||||||
Mn | 25 | 48 | 72.99281(64)# | 12# ms |
β? | Fe | 5/2−# | ||||||||||||
This table header & footer: |
- Mn – Excited nuclear isomer.
- ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
- # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
-
Modes of decay:
EC: Electron capture IT: Isomeric transition n: Neutron emission p: Proton emission - Bold symbol as daughter – Daughter product is stable.
- ( ) spin value – Indicates spin with weak assignment arguments.
- ^ # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
- Order of ground state and isomer is uncertain.
References
- 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.
- "Standard Atomic Weights: Manganese". CIAAW. 2017.
- 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.
- 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.
- Isotope masses from:
- Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
- Half-life, spin, and isomer data selected from the following sources.
- Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
- National Nuclear Data Center. "NuDat 2.x database". Brookhaven National Laboratory.
- Holden, Norman E. (2004). "11. Table of the Isotopes". In Lide, David R. (ed.). CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9.