# Isotopes of manganese

Naturally occurring manganese ($_{25}$Mn) is composed of one stable isotope, $^{55}$Mn. Twenty-seven radioisotopes have been characterized, with the most stable being $^{53}$Mn with a half-life of 3.7 million years, $^{54}$Mn with a half-life of 312.3 days, and $^{52}$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. $^{53}$Mn decays to $^{53}$Cr with a half-life of 3.7 million years. Because of its relatively short half-life, $^{53}$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 $^{26}$Al and $^{107}$Pd for the early history of the Solar System. Variations in $^{53}$Cr/$^{52}$Cr and Mn/Cr ratios from several meteorites indicate an initial $^{53}$Mn/$^{55}$Mn ratio that suggests Mn−Cr isotopic systematics must result from in-situ decay of $^{53}$Mn in differentiated planetary bodies. Hence $^{53}$Mn provides additional evidence for nucleosynthetic processes immediately before coalescence of the Solar System.
The isotopes of manganese range from $^{46}$Mn to $^{73}$Mn. The primary decay mode before the most abundant stable isotope, $^{55}$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 |
| Isotopic abundance |||
| $^{46}$Mn | 25 | 21 | 45.986669(93) | 36.2(4) ms | β$^+$, p (57.0%) | $^{45}$V | (4+) | |
| $^{46}$Mn | 25 | 21 | 45.986669(93) | 36.2(4) ms | β$^+$ (25%) | $^{46}$Cr | (4+) | |
| $^{46}$Mn | 25 | 21 | 45.986669(93) | 36.2(4) ms | β$^+$, 2p (18%) | $^{44}$Ti | (4+) | |
| $^{46}$Mn | 25 | 21 | 45.986669(93) | 36.2(4) ms | β$^+$, α? | $^{42}$Ti | (4+) | |
| $^{47}$Mn | 25 | 22 | 46.975774(34) | 88.0(13) ms | β$^+$ | $^{47}$Cr | 5/2−# | |
| $^{47}$Mn | 25 | 22 | 46.975774(34) | 88.0(13) ms | β$^+$, p? (<1.7%) | $^{46}$V | 5/2−# | |
| $^{48}$Mn | 25 | 23 | 47.9685488(72) | 158.1(22) ms | β$^+$ (99.72%) | $^{48}$Cr | 4+ | |
| $^{48}$Mn | 25 | 23 | 47.9685488(72) | 158.1(22) ms | β$^+$, p (0.28%) | $^{47}$V | 4+ | |
| $^{48}$Mn | 25 | 23 | 47.9685488(72) | 158.1(22) ms | β$^+$, α (6×10$^{−4}$%) | $^{44}$Ti | 4+ | |
| $^{49}$Mn | 25 | 24 | 48.9596134(24) | 382(7) ms | β$^+$ | $^{49}$Cr | 5/2− | |
| $^{50}$Mn | 25 | 25 | 49.95423816(12) | 283.21(7) ms | β$^+$ | $^{50}$Cr | 0+ | |
| $^{50m}$Mn | 225.31(7) keV | 225.31(7) keV | 225.31(7) keV | 1.75(3) min | β$^+$ | $^{50}$Cr | 5+ | |
| $^{51}$Mn | 25 | 26 | 50.94820877(33) | 45.81(21) min | β$^+$ | $^{51}$Cr | 5/2− | |
| $^{52}$Mn | 25 | 27 | 51.94555909(14) | 5.591(3) d | β$^+$ | $^{52}$Cr | 6+ | |
| $^{52m}$Mn | 377.749(5) keV | 377.749(5) keV | 377.749(5) keV | 21.1(2) min | β$^+$ (98.22%) | $^{52}$Cr | 2+ | |
| $^{52m}$Mn | 377.749(5) keV | 377.749(5) keV | 377.749(5) keV | 21.1(2) min | IT (1.78%) | $^{52}$Mn | 2+ | |
| $^{53}$Mn | 25 | 28 | 52.94128750(37) | 3.7(4)×10$^6$ y | EC | $^{53}$Cr | 7/2− | trace |
| $^{54}$Mn | 25 | 29 | 53.9403558(11) | 312.081(32) d | EC | $^{54}$Cr | 3+ | |
| $^{54}$Mn | 25 | 29 | 53.9403558(11) | 312.081(32) d | β$^−$ (9.3×10$^{−5}$%) | $^{54}$Fe | 3+ | |
| $^{54}$Mn | 25 | 29 | 53.9403558(11) | 312.081(32) d | β$^+$ (1.28×10$^{−7}$%) | $^{54}$Cr | 3+ | |
| $^{55}$Mn | 25 | 30 | 54.93804304(28) | Stable | Stable | Stable | 5/2− | 1.0000 |
| $^{56}$Mn | 25 | 31 | 55.93890282(31) | 2.5789(1) h | β$^−$ | $^{56}$Fe | 3+ | |
| $^{57}$Mn | 25 | 32 | 56.9382859(16) | 85.4(18) s | β$^−$ | $^{57}$Fe | 5/2− | |
| $^{58}$Mn | 25 | 33 | 57.9400666(29) | 3.0(1) s | β$^−$ | $^{58}$Fe | 1+ | |
| $^{58m}$Mn | 71.77(5) keV | 71.77(5) keV | 71.77(5) keV | 65.4(5) s | β$^−$ | $^{58}$Fe | 4+ | |
| $^{58m}$Mn | 71.77(5) keV | 71.77(5) keV | 71.77(5) keV | 65.4(5) s | IT? | $^{58}$Mn | 4+ | |
| $^{59}$Mn | 25 | 34 | 58.9403911(25) | 4.59(5) s | β$^−$ | $^{59}$Fe | 5/2− | |
| $^{60}$Mn | 25 | 35 | 59.9431366(25) | 280(20) ms | β$^−$ | $^{60}$Fe | 1+ | |
| $^{60m}$Mn | 271.90(10) keV | 271.90(10) keV | 271.90(10) keV | 1.77(2) s | β$^−$ (88.5%) | $^{60}$Fe | 4+ | |
| $^{60m}$Mn | 271.90(10) keV | 271.90(10) keV | 271.90(10) keV | 1.77(2) s | IT (11.5%) | $^{60}$Mn | 4+ | |
| $^{61}$Mn | 25 | 36 | 60.9444525(25) | 709(8) ms | β$^−$ | $^{61}$Fe | 5/2− | |
| $^{61}$Mn | 25 | 36 | 60.9444525(25) | 709(8) ms | β$^−$, n? | $^{60}$Fe | 5/2− | |
| $^{62}$Mn | 25 | 37 | 61.9479074(70) | 92(13) ms | β$^−$ | $^{62}$Fe | 1+ | |
| $^{62}$Mn | 25 | 37 | 61.9479074(70) | 92(13) ms | β$^−$, n? | $^{61}$Fe | 1+ | |
| $^{62m}$Mn | 343(6) keV | 343(6) keV | 343(6) keV | 671(5) ms | β$^−$ | $^{62}$Fe | 4+ | |
| $^{62m}$Mn | 343(6) keV | 343(6) keV | 343(6) keV | 671(5) ms | β$^−$, n? | $^{61}$Fe | 4+ | |
| $^{62m}$Mn | 343(6) keV | 343(6) keV | 343(6) keV | 671(5) ms | IT? | $^{61}$Mn | 4+ | |
| $^{63}$Mn | 25 | 38 | 62.9496647(40) | 275(4) ms | β$^−$ | $^{63}$Fe | 5/2− | |
| $^{63}$Mn | 25 | 38 | 62.9496647(40) | 275(4) ms | β$^−$, n? | $^{62}$Fe | 5/2− | |
| $^{64}$Mn | 25 | 39 | 63.9538494(38) | 88.8(24) ms | β$^−$ (97.3%) | $^{64}$Fe | 1+ | |
| $^{64}$Mn | 25 | 39 | 63.9538494(38) | 88.8(24) ms | β$^−$, n (2.7%) | $^{63}$Fe | 1+ | |
| $^{64m}$Mn | 174.1(5) keV | 174.1(5) keV | 174.1(5) keV | 439(31) μs | IT | $^{64}$Mn | (4+) | |
| $^{65}$Mn | 25 | 40 | 64.9560197(40) | 91.9(7) ms | β$^−$ (92.1%) | $^{65}$Fe | (5/2−) | |
| $^{65}$Mn | 25 | 40 | 64.9560197(40) | 91.9(7) ms | β$^−$, n (7.9%) | $^{64}$Fe | (5/2−) | |
| $^{66}$Mn | 25 | 41 | 65.960547(12) | 63.8(9) ms | β$^−$ (92.6%) | $^{66}$Fe | (1+) | |
| $^{66}$Mn | 25 | 41 | 65.960547(12) | 63.8(9) ms | β$^−$, n (7.4%) | $^{65}$Fe | (1+) | |
| $^{66}$Mn | 25 | 41 | 65.960547(12) | 63.8(9) ms | β$^−$, 2n? | $^{64}$Fe | (1+) | |
| $^{66m}$Mn | 464.5(4) keV | 464.5(4) keV | 464.5(4) keV | 780(40) μs | IT | $^{66}$Mn | (5−) | |
| $^{66m}$Mn | 464.5(4) keV | 464.5(4) keV | 464.5(4) keV | 780(40) μs | β$^−$? | $^{66}$Fe | (5−) | |
| $^{67}$Mn | 25 | 42 | 66.96395(22)# | 46.7(23) ms | β$^−$ (90%) | $^{67}$Fe | 5/2−# | |
| $^{67}$Mn | 25 | 42 | 66.96395(22)# | 46.7(23) ms | β$^−$, n (10%) | $^{66}$Fe | 5/2−# | |
| $^{67}$Mn | 25 | 42 | 66.96395(22)# | 46.7(23) ms | β$^−$, 2n? | $^{65}$Fe | 5/2−# | |
| $^{68}$Mn | 25 | 43 | 67.96895(32)# | 33.7(15) ms | β$^−$ (82%) | $^{68}$Fe | (3) | |
| $^{68}$Mn | 25 | 43 | 67.96895(32)# | 33.7(15) ms | β$^−$, n (18%) | $^{67}$Fe | (3) | |
| $^{68}$Mn | 25 | 43 | 67.96895(32)# | 33.7(15) ms | β$^−$, 2n? | $^{66}$Fe | (3) | |
| $^{69}$Mn | 25 | 44 | 68.97278(43)# | 22.1(16) ms | β$^−$ (60%) | $^{69}$Fe | 5/2−# | |
| $^{69}$Mn | 25 | 44 | 68.97278(43)# | 22.1(16) ms | β$^−$, n (40%) | $^{68}$Fe | 5/2−# | |
| $^{69}$Mn | 25 | 44 | 68.97278(43)# | 22.1(16) ms | β$^−$, 2n? | $^{67}$Fe | 5/2−# | |
| $^{70}$Mn | 25 | 45 | 69.97805(54)# | 19.9(17) ms | β$^−$ | $^{70}$Fe | (4,5) | |
| $^{70}$Mn | 25 | 45 | 69.97805(54)# | 19.9(17) ms | β$^−$, n? | $^{69}$Fe | (4,5) | |
| $^{70}$Mn | 25 | 45 | 69.97805(54)# | 19.9(17) ms | β$^−$, 2n? | $^{68}$Fe | (4,5) | |
| $^{71}$Mn | 25 | 46 | 70.98216(54)# | 16# ms [>400 ns] | β$^−$? | $^{71}$Fe | 5/2-# | |
| $^{71}$Mn | 25 | 46 | 70.98216(54)# | 16# ms [>400 ns] | β$^−$, n? | $^{70}$Fe | 5/2-# | |
| $^{71}$Mn | 25 | 46 | 70.98216(54)# | 16# ms [>400 ns] | β$^−$, 2n? | $^{69}$Fe | 5/2-# | |
| $^{72}$Mn | 25 | 47 | 71.98801(64)# | 12# ms [>620 ns] | β$^−$? | $^{72}$Fe | | |
| $^{72}$Mn | 25 | 47 | 71.98801(64)# | 12# ms [>620 ns] | β$^−$, n? | $^{71}$Fe | | |
| $^{72}$Mn | 25 | 47 | 71.98801(64)# | 12# ms [>620 ns] | β$^−$, 2n? | $^{70}$Fe | | |
| $^{73}$Mn | 25 | 48 | 72.99281(64)# | 12# ms [>410 ns] | β$^−$? | $^{73}$Fe | 5/2−# | |
| This table header & footer: view |||||||||
* ↑ $^m$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.
* 1 2 # – 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.