Naturally occurring

manganese Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy use ...

(₂₅Mn) is composed of one stable

isotope Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers (mass numb ...

, ⁵⁵Mn. 25

radioisotope A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transferr ...

s have been characterized, with the most stable being ⁵³Mn with a

half-life Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable at ...

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 Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consi ...

isotopes have half-lives that are less than 3 hours and the majority of these have half-lives that are less than a minute, but only ⁴⁵Mn has an unknown half-life. The least stable is ⁴⁴Mn with a half-life shorter than 105 nanoseconds. This element also has 3

meta state A nuclear isomer is a metastable state of an atomic nucleus, in which one or more nucleons (protons or neutrons) occupy higher energy levels than in the ground state of the same nucleus. "Metastable" describes nuclei whose excited states have ...

s. Manganese is part of the

iron Iron () is a chemical element with Symbol (chemistry), symbol Fe (from la, Wikt:ferrum, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 element, group 8 of the periodic table. It is, Abundanc ...

group of elements, which are thought to be synthesized in large stars shortly before supernova explosions. ⁵³Mn decays to ⁵³ Cr with a

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 Cosmic rays are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar System in our ow ...

in rocks. Manganese isotopic contents are typically combined with chromium isotopic contents and have found application in

isotope geology Isotope geochemistry is an aspect of geology based upon the study of natural variations in the relative abundances of isotopes of various elements. Variations in isotopic abundance are measured by isotope ratio mass spectrometry, and can reveal ...

and

radiometric dating Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares ...

. Mn−Cr isotopic ratios reinforce the evidence from ²⁶Al and ¹⁰⁷ Pd for the early history of the

Solar System The Solar System Capitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar ...

. 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 Nucleosynthesis is the process that creates new atomic nuclei from pre-existing nucleons (protons and neutrons) and nuclei. According to current theories, the first nuclei were formed a few minutes after the Big Bang, through nuclear reactions in ...

processes immediately before coalescence of the

. The isotopes of manganese range in

atomic weight Relative atomic mass (symbol: ''A''; sometimes abbreviated RAM or r.a.m.), also known by the deprecated synonym atomic weight, is a dimensionless physical quantity defined as the ratio of the average mass of atoms of a chemical element in a giv ...

from 44 u (⁴⁴Mn) to 69 u (⁶⁹Mn). The primary decay mode before the most abundant stable isotope, ⁵⁵Mn, is

electron capture Electron capture (K-electron capture, also K-capture, or L-electron capture, L-capture) is a process in which the proton-rich nucleus of an electrically neutral atom absorbs an inner atomic electron, usually from the K or L electron shells. Thi ...

and the primary mode after is

beta decay In nuclear physics, beta decay (β-decay) is a type of radioactive decay in which a beta particle (fast energetic electron or positron) is emitted from an atomic nucleus, transforming the original nuclide to an isobar of that nuclide. For ...

List of isotopes

, - , ⁴⁴Mn , style="text-align:right" , 25 , style="text-align:right" , 19 , 44.00687(54)# , <105 ns , p , ⁴³Cr , (2−)# , , , - , ⁴⁵Mn , style="text-align:right" , 25 , style="text-align:right" , 20 , 44.99451(32)# , unknown , p , ⁴⁴Cr , (7/2−)# , , , - , rowspan=4, ⁴⁶Mn , rowspan=4 style="text-align:right" , 25 , rowspan=4 style="text-align:right" , 21 , rowspan=4, 45.98672(12)# , rowspan=4, 37(3) ms , β⁺ (78%) , ⁴⁶Cr , rowspan=4, (4+) , rowspan=4, , rowspan=4, , - , β⁺, p (22%) , ⁴⁵V , - , β⁺, α (<1%) , ⁴²Ti , - , β⁺, 2p (<1%) , ⁴⁴Ti , - , style="text-indent:1em" , ^46mMn , colspan="3" style="text-indent:2em" , 150(100)# keV , 1# ms , β⁺ , ⁴⁶Cr , 1-# , , , - , rowspan=2, ⁴⁷Mn , rowspan=2 style="text-align:right" , 25 , rowspan=2 style="text-align:right" , 22 , rowspan=2, 46.97610(17)# , rowspan=2, 100(50) ms , β⁺ (96.6%) , ⁴⁷Cr , rowspan=2, 5/2−# , rowspan=2, , rowspan=2, , - , β⁺, p (3.4%) , ⁴⁶V , - , rowspan=3, ⁴⁸Mn , rowspan=3 style="text-align:right" , 25 , rowspan=3 style="text-align:right" , 23 , rowspan=3, 47.96852(12) , rowspan=3, 158.1(22) ms , β⁺ (99.71%) , ⁴⁸Cr , rowspan=3, 4+ , rowspan=3, , rowspan=3, , - , β⁺, p (.027%) , ⁴⁷V , - , β⁺, α (6×10⁻⁴%) , ⁴⁴Ti , - , ⁴⁹Mn , style="text-align:right" , 25 , style="text-align:right" , 24 , 48.959618(26) , 382(7) ms , β⁺ , ⁴⁹Cr , 5/2− , , , - , ⁵⁰Mn , style="text-align:right" , 25 , style="text-align:right" , 25 , 49.9542382(11) , 283.29(8) ms , β⁺ , ⁵⁰Cr , 0+ , , , - , style="text-indent:1em" , ^50mMn , colspan="3" style="text-indent:2em" , 229(7) keV , 1.75(3) min , β⁺ , ⁵⁰Cr , 5+ , , , - , ⁵¹Mn , style="text-align:right" , 25 , style="text-align:right" , 26 , 50.9482108(11) , 46.2(1) min , β⁺ , ⁵¹Cr , 5/2− , , , - , ⁵²Mn , style="text-align:right" , 25 , style="text-align:right" , 27 , 51.9455655(21) , 5.591(3) d , β⁺ , ⁵²Cr , 6+ , , , - , rowspan=2 style="text-indent:1em" , ^52mMn , rowspan=2 colspan="3" style="text-indent:2em" , 377.749(5) keV , rowspan=2, 21.1(2) min , β⁺ (98.25%) , ⁵²Cr , rowspan=2, 2+ , rowspan=2, , rowspan=2, , - , IT (1.75%) , ⁵²Mn , - , ⁵³Mn , style="text-align:right" , 25 , style="text-align:right" , 28 , 52.9412901(9) , 3.7(4)×10⁶ y , EC , ⁵³Cr , 7/2− ,

trace Trace may refer to: Arts and entertainment Music * ''Trace'' (Son Volt album), 1995 * ''Trace'' (Died Pretty album), 1993 * Trace (band), a Dutch progressive rock band * ''The Trace'' (album) Other uses in arts and entertainment * ''Trace'' ...

, , - , rowspan=3, ⁵⁴Mn , rowspan=3 style="text-align:right" , 25 , rowspan=3 style="text-align:right" , 29 , rowspan=3, 53.9403589(14) , rowspan=3, 312.03(3) d , EC 99.99% , ⁵⁴Cr , rowspan=3, 3+ , rowspan=3, , rowspan=3, , - , β⁻ (2.9×10⁻⁴%) , ⁵⁴Fe , - , β⁺ (5.76×10⁻⁷%) , ⁵⁴Cr , - , ⁵⁵Mn , style="text-align:right" , 25 , style="text-align:right" , 30 , 54.9380451(7) , colspan=3 align=center, Stable , 5/2− , 1.0000 , , - , ⁵⁶Mn , style="text-align:right" , 25 , style="text-align:right" , 31 , 55.9389049(7) , 2.5789(1) h , β⁻ , ⁵⁶Fe , 3+ , , , - , ⁵⁷Mn , style="text-align:right" , 25 , style="text-align:right" , 32 , 56.9382854(20) , 85.4(18) s , β⁻ , ⁵⁷Fe , 5/2− , , , - , ⁵⁸Mn , style="text-align:right" , 25 , style="text-align:right" , 33 , 57.93998(3) , 3.0(1) s , β⁻ , ⁵⁸Fe , 1+ , , , - , rowspan=2 style="text-indent:1em" , ^58mMn , rowspan=2 colspan="3" style="text-indent:2em" , 71.78(5) keV , rowspan=2, 65.2(5) s , β⁻ (>99.9%) , ⁵⁸Fe , rowspan=2, (4)+ , rowspan=2, , rowspan=2, , - , IT (<.1%) , ⁵⁸Mn , - , ⁵⁹Mn , style="text-align:right" , 25 , style="text-align:right" , 34 , 58.94044(3) , 4.59(5) s , β⁻ , ⁵⁹Fe , (5/2)− , , , - , ⁶⁰Mn , style="text-align:right" , 25 , style="text-align:right" , 35 , 59.94291(9) , 51(6) s , β⁻ , ⁶⁰Fe , 0+ , , , - , rowspan=2 style="text-indent:1em" , ^60mMn , rowspan=2 colspan="3" style="text-indent:2em" , 271.90(10) keV , rowspan=2, 1.77(2) s , β⁻ (88.5%) , ⁶⁰Fe , rowspan=2, 3+ , rowspan=2, , rowspan=2, , - , IT (11.5%) , ⁶⁰Mn , - , ⁶¹Mn , style="text-align:right" , 25 , style="text-align:right" , 36 , 60.94465(24) , 0.67(4) s , β⁻ , ⁶¹Fe , (5/2)− , , , - , rowspan=2, ⁶²Mn , rowspan=2 style="text-align:right" , 25 , rowspan=2 style="text-align:right" , 37 , rowspan=2, 61.94843(24) , rowspan=2, 671(5) ms , β⁻ (>99.9%) , ⁶²Fe , rowspan=2, (3+) , rowspan=2, , rowspan=2, , - , β⁻, n (<.1%) , ⁶¹Fe , - , style="text-indent:1em" , ^62mMn , colspan="3" style="text-indent:2em" , 0(150)# keV , 92(13) ms , , , (1+) , , , - , ⁶³Mn , style="text-align:right" , 25 , style="text-align:right" , 38 , 62.95024(28) , 275(4) ms , β⁻ , ⁶³Fe , 5/2−# , , , - , rowspan=2, ⁶⁴Mn , rowspan=2 style="text-align:right" , 25 , rowspan=2 style="text-align:right" , 39 , rowspan=2, 63.95425(29) , rowspan=2, 88.8(25) ms , β⁻ (>99.9%) , ⁶⁴Fe , rowspan=2, (1+) , rowspan=2, , rowspan=2, , - , β⁻, n (<.1%) , ⁶³Fe , - , style="text-indent:1em" , ^64mMn , colspan="3" style="text-indent:2em" , 135(3) keV , >100 µs , , , , , , - , rowspan=2, ⁶⁵Mn , rowspan=2 style="text-align:right" , 25 , rowspan=2 style="text-align:right" , 40 , rowspan=2, 64.95634(58) , rowspan=2, 92(1) ms , β⁻ (>99.9%) , ⁶⁵Fe , rowspan=2, 5/2−# , rowspan=2, , rowspan=2, , - , β⁻, n (<.1%) , ⁶⁴Fe , - , rowspan=2, ⁶⁶Mn , rowspan=2 style="text-align:right" , 25 , rowspan=2 style="text-align:right" , 41 , rowspan=2, 65.96108(43)# , rowspan=2, 64.4(18) ms , β⁻ (>99.9%) , ⁶⁶Fe , rowspan=2, , rowspan=2, , rowspan=2, , - , β⁻, n (<.1%) , ⁶⁵Fe , - , ⁶⁷Mn , style="text-align:right" , 25 , style="text-align:right" , 42 , 66.96414(54)# , 45(3) ms , β⁻ , ⁶⁷Fe , 5/2−# , , , - , ⁶⁸Mn , style="text-align:right" , 25 , style="text-align:right" , 43 , 67.96930(64)# , 28(4) ms , , , , , , - , ⁶⁹Mn , style="text-align:right" , 25 , style="text-align:right" , 44 , 68.97284(86)# , 14(4) ms , , , 5/2−# , ,

References

* Isotope masses from: ** * Isotopic compositions and standard atomic masses from: ** ** * Half-life, spin, and isomer data selected from the following sources. ** ** ** {{Navbox element isotopes Manganese

Manganese Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy use ...