Isotopes of manganese

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 312.08 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 massive stars shortly before supernova explosions. Because of its relatively short half-life, ⁵³Mn occurs on Earth only in tiny amounts due to the action of cosmic rays on iron in rocks.

As ⁵³Mn decays to ⁵³Cr, manganese isotopic analysis is typically combined with that of chromium and this has 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 a non-zero initial ⁵³Mn/⁵⁵Mn ratio that implies Cr isotopic variations must result from in-situ decay of ⁵³Mn in differentiated planetary bodies. Hence ⁵³Mn provides additional evidence for nucleosynthetic processes shortly 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

|-id=Manganese-46 | rowspan=4|⁴⁶Mn | rowspan=4 style="text-align:right" | 25 | rowspan=4 style="text-align:right" | 21 | rowspan=4|45.986669(93) | rowspan=4|36.2(4)&nbsp;ms | β⁺, p (57.0%) | ⁴⁵V | rowspan=4|(4+) | rowspan=4| |- | β⁺ (25%) | ⁴⁶Cr |- | β⁺, 2p (18%) | ⁴⁴Ti |- | β⁺, α? | ⁴²Ti |-id=Manganese-47 | rowspan=2|⁴⁷Mn | rowspan=2 style="text-align:right" | 25 | rowspan=2 style="text-align:right" | 22 | rowspan=2|46.975774(34) | rowspan=2|88.0(13)&nbsp;ms | β⁺ | ⁴⁷Cr | rowspan=2|5/2−# | rowspan=2| |- | β⁺, p? (<1.7%) | ⁴⁶V |-id=Manganese-48 | rowspan=3|⁴⁸Mn | rowspan=3 style="text-align:right" | 25 | rowspan=3 style="text-align:right" | 23 | rowspan=3|47.9685488(72) | rowspan=3|158.1(22)&nbsp;ms | β⁺ (99.72%) | ⁴⁸Cr | rowspan=3|4+ | rowspan=3| |- | β⁺, p (0.28%) | ⁴⁷V |- | β⁺, α (6×10^{−4}%) | ⁴⁴Ti |-id=Manganese-49 | ⁴⁹Mn | style="text-align:right" | 25 | style="text-align:right" | 24 | 48.9596134(24) | 382(7)&nbsp;ms | β⁺ | ⁴⁹Cr | 5/2− | |-id=Manganese-50 | ⁵⁰Mn | style="text-align:right" | 25 | style="text-align:right" | 25 | 49.95423816(12) | 283.21(7)&nbsp;ms | β⁺ | ⁵⁰Cr | 0+ | |-id=Manganese-50m | style="text-indent:1em" | ^50mMn | colspan="3" style="text-indent:2em" | 225.31(7)&nbsp;keV | 1.75(3)&nbsp;min | β⁺ | ⁵⁰Cr | 5+ | |-id=Manganese-51 | ⁵¹Mn | style="text-align:right" | 25 | style="text-align:right" | 26 | 50.94820877(33) | 45.81(21)&nbsp;min | β⁺ | ⁵¹Cr | 5/2− | |-id=Manganese-52 | ⁵²Mn | style="text-align:right" | 25 | style="text-align:right" | 27 | 51.94555909(14) | 5.591(3)&nbsp;d | β⁺ | ⁵²Cr | 6+ | |-id=Manganese-52m | rowspan=2 style="text-indent:1em" | ^52mMn | rowspan=2 colspan="3" style="text-indent:2em" | 377.749(5)&nbsp;keV | rowspan=2|21.1(2)&nbsp;min | β⁺ (98.22%) | ⁵²Cr | rowspan=2|2+ | rowspan=2| |- | IT (1.78%) | ⁵²Mn |-id=Manganese-53 | ⁵³Mn | style="text-align:right" | 25 | style="text-align:right" | 28 | 52.94128750(37) | 3.7(4)×10⁶ y | EC | ⁵³Cr | 7/2− | trace |-id=Manganese-54 | rowspan=3|⁵⁴Mn | rowspan=3 style="text-align:right" | 25 | rowspan=3 style="text-align:right" | 29 | rowspan=3|53.9403558(11) | rowspan=3|312.081(32)&nbsp;d | EC | ⁵⁴Cr | rowspan=3|3+ | rowspan=3| |- | β^− (9.3×10^{−5}%) | ⁵⁴Fe |- | β⁺ (1.28×10^{−7}%) | ⁵⁴Cr |-id=Manganese-55 | ⁵⁵Mn | style="text-align:right" | 25 | style="text-align:right" | 30 | 54.93804304(28) | colspan=3 align=center|Stable | 5/2− | 1.0000 |-id=Manganese-56 | ⁵⁶Mn | style="text-align:right" | 25 | style="text-align:right" | 31 | 55.93890282(31) | 2.5789(1)&nbsp;h | β^− | ⁵⁶Fe | 3+ | |-id=Manganese-57 | ⁵⁷Mn | style="text-align:right" | 25 | style="text-align:right" | 32 | 56.9382859(16) | 85.4(18)&nbsp;s | β^− | ⁵⁷Fe | 5/2− | |-id=Manganese-58 | ⁵⁸Mn | style="text-align:right" | 25 | style="text-align:right" | 33 | 57.9400666(29) | 3.0(1)&nbsp;s | β^− | ⁵⁸Fe | 1+ | |-id=Manganese-58m | rowspan=2 style="text-indent:1em" | ^58mMn | rowspan=2 colspan="3" style="text-indent:2em" | 71.77(5)&nbsp;keV | rowspan=2|65.4(5)&nbsp;s | β^− | ⁵⁸Fe | rowspan=2|4+ | rowspan=2| |- | IT? | ⁵⁸Mn |-id=Manganese-59 | ⁵⁹Mn | style="text-align:right" | 25 | style="text-align:right" | 34 | 58.9403911(25) | 4.59(5)&nbsp;s | β^− | ⁵⁹Fe | 5/2− | |-id=Manganese-60 | ⁶⁰Mn | style="text-align:right" | 25 | style="text-align:right" | 35 | 59.9431366(25) | 280(20)&nbsp;ms | β^− | ⁶⁰Fe | 1+ | |-id=Manganese-60m | rowspan=2 style="text-indent:1em" | ^60mMn | rowspan=2 colspan="3" style="text-indent:2em" | 271.90(10)&nbsp;keV | rowspan=2|1.77(2)&nbsp;s | β^− (88.5%) | ⁶⁰Fe | rowspan=2|4+ | rowspan=2| |- | IT (11.5%) | ⁶⁰Mn |-id=Manganese-61 | rowspan=2|⁶¹Mn | rowspan=2 style="text-align:right" | 25 | rowspan=2 style="text-align:right" | 36 | rowspan=2|60.9444525(25) | rowspan=2|709(8)&nbsp;ms | β^− | ⁶¹Fe | rowspan=2|5/2− | rowspan=2| |- | β^−, n? | ⁶⁰Fe |-id=Manganese-62 | rowspan=2|⁶²Mn | rowspan=2 style="text-align:right" | 25 | rowspan=2 style="text-align:right" | 37 | rowspan=2|61.9479074(70) | rowspan=2|92(13)&nbsp;ms | β^− | ⁶²Fe | rowspan=2|1+ | rowspan=2| |- | β^−, n? | ⁶¹Fe |-id=Manganese-62m | rowspan=3 style="text-indent:1em" | ^62mMn | rowspan=3 colspan="3" style="text-indent:2em" | 343(6)&nbsp;keV | rowspan=3|671(5)&nbsp;ms | β^− | ⁶²Fe | rowspan=3|4+ | rowspan=3| |- | β^−, n? | ⁶¹Fe |- | IT? | ⁶²Mn |-id=Manganese-63 | rowspan=2|⁶³Mn | rowspan=2 style="text-align:right" | 25 | rowspan=2 style="text-align:right" | 38 | rowspan=2|62.9496647(40) | rowspan=2|275(4)&nbsp;ms | β^− | ⁶³Fe | rowspan=2|5/2− | rowspan=2| |- | β^−, n? | ⁶²Fe |-id=Manganese-64 | rowspan=2|⁶⁴Mn | rowspan=2 style="text-align:right" | 25 | rowspan=2 style="text-align:right" | 39 | rowspan=2|63.9538494(38) | rowspan=2|88.8(24)&nbsp;ms | β^− (97.3%) | ⁶⁴Fe | rowspan=2|1+ | rowspan=2| |- | β^−, n (2.7%) | ⁶³Fe |-id=Manganese-64m | style="text-indent:1em" | ^64mMn | colspan="3" style="text-indent:2em" | 174.1(5)&nbsp;keV | 439(31)&nbsp;μs | IT | ⁶⁴Mn | (4+) | |-id=Manganese-65 | rowspan=2|⁶⁵Mn | rowspan=2 style="text-align:right" | 25 | rowspan=2 style="text-align:right" | 40 | rowspan=2|64.9560197(40) | rowspan=2|91.9(7)&nbsp;ms | β^− (92.1%) | ⁶⁵Fe | rowspan=2|(5/2−) | rowspan=2| |- | β^−, n (7.9%) | ⁶⁴Fe |-id=Manganese-66 | rowspan=3|⁶⁶Mn | rowspan=3 style="text-align:right" | 25 | rowspan=3 style="text-align:right" | 41 | rowspan=3|65.960547(12) | rowspan=3|63.8(9)&nbsp;ms | β^− (92.6%) | ⁶⁶Fe | rowspan=3|(1+) | rowspan=3| |- | β^−, n (7.4%) | ⁶⁵Fe |- | β^−, 2n? | ⁶⁴Fe |-id=Manganese-66m | rowspan=2 style="text-indent:1em" | ^66mMn | rowspan=2 colspan="3" style="text-indent:2em" | 464.5(4)&nbsp;keV | rowspan=2|780(40)&nbsp;μs | IT | ⁶⁶Mn | rowspan=2|(5−) | rowspan=2| |- | β^−? | ⁶⁶Fe |-id=Manganese-67 | rowspan=3|⁶⁷Mn | rowspan=3 style="text-align:right" | 25 | rowspan=3 style="text-align:right" | 42 | rowspan=3|66.96395(22)# | rowspan=3|46.7(23)&nbsp;ms | β^− (90%) | ⁶⁷Fe | rowspan=3|5/2−# | rowspan=3| |- | β^−, n (10%) | ⁶⁶Fe |- | β^−, 2n? | ⁶⁵Fe |-id=Manganese-68 | rowspan=3|⁶⁸Mn | rowspan=3 style="text-align:right" | 25 | rowspan=3 style="text-align:right" | 43 | rowspan=3|67.96895(32)# | rowspan=3|33.7(15)&nbsp;ms | β^− (82%) | ⁶⁸Fe | rowspan=3|(3) | rowspan=3| |- | β^−, n (18%) | ⁶⁷Fe |- | β^−, 2n? | ⁶⁶Fe |-id=Manganese-69 | rowspan=3|⁶⁹Mn | rowspan=3 style="text-align:right" | 25 | rowspan=3 style="text-align:right" | 44 | rowspan=3|68.97278(43)# | rowspan=3|22.1(16)&nbsp;ms | β^− (60%) | ⁶⁹Fe | rowspan=3|5/2−# | rowspan=3| |- | β^−, n (40%) | ⁶⁸Fe |- | β^−, 2n? | ⁶⁷Fe |-id=Manganese-70 | rowspan=3|⁷⁰Mn | rowspan=3 style="text-align:right" | 25 | rowspan=3 style="text-align:right" | 45 | rowspan=3|69.97805(54)# | rowspan=3|19.9(17)&nbsp;ms | β^− | ⁷⁰Fe | rowspan=3| (4,5) | rowspan=3| |- | β^−, n? | ⁶⁹Fe |- | β^−, 2n? | ⁶⁸Fe |-id=Manganese-71 | rowspan=3|⁷¹Mn | rowspan=3 style="text-align:right" | 25 | rowspan=3 style="text-align:right" | 46 | rowspan=3|70.98216(54)# | rowspan=3|16#&nbsp;ms<br>[>400&nbsp;ns] | β^−? | ⁷¹Fe | rowspan=3| 5/2-# | rowspan=3| |- | β^−, n? | ⁷⁰Fe |- | β^−, 2n? | ⁶⁹Fe |-id=Manganese-72 | rowspan=3|⁷²Mn | rowspan=3 style="text-align:right" | 25 | rowspan=3 style="text-align:right" | 47 | rowspan=3|71.98801(64)# | rowspan=3|12#&nbsp;ms<br/>[>620&nbsp;ns] | β^−? | ⁷²Fe | rowspan=3| | rowspan=3| |- | β^−, n? | ⁷¹Fe |- | β^−, 2n? | ⁷⁰Fe |-id=Manganese-73 | ⁷³Mn | style="text-align:right" | 25 | style="text-align:right" | 48 | 72.99281(64)# | 12#&nbsp;ms<br/>[>410&nbsp;ns] | β^−? | ⁷³Fe | 5/2−# |

See also

Daughter products other than manganese

• Isotopes of iron
• Isotopes of chromium
• Isotopes of vanadium
• Isotopes of titanium

References

• Isotope masses from:
• Half-life, spin, and isomer data selected from the following sources.