Isotopes of manganese
Encyclopedia
Naturally occurring manganese
(Mn) is composed of 1 stable isotope
; 55Mn. 25 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 1 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 states.
Manganese is part of the iron
group of elements which are thought to be synthesized in large star
s shortly before supernova
explosion. 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. 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 meteorite
s 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 in atomic weight
from 46 u
(46Mn) to 65 u (65Mn). The primary decay mode before the most abundant stable isotope, 55Mn, is electron capture
and the primary mode after is beta decay
.
Standard atomic mass: 54.938045(5) u
Manganese
Manganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals...
(Mn) is composed of 1 stable isotope
Isotope
Isotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation...
; 55Mn. 25 radioisotopes have been characterized with the most stable being 53Mn with a half-life
Half-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...
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 1 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 states.
Manganese is part of the iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
group of elements which are thought to be synthesized in large star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
s shortly before supernova
Supernova
A supernova is a stellar explosion that is more energetic than a nova. It is pronounced with the plural supernovae or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months...
explosion. 53Mn decays to 53Cr
Chromium
Chromium is a chemical element which has the symbol Cr and atomic number 24. It is the first element in Group 6. It is a steely-gray, lustrous, hard metal that takes a high polish and has a high melting point. It is also odorless, tasteless, and malleable...
with a half-life
Half-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...
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
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
in rocks. Manganese isotopic contents are typically combined with chromium
Chromium
Chromium is a chemical element which has the symbol Cr and atomic number 24. It is the first element in Group 6. It is a steely-gray, lustrous, hard metal that takes a high polish and has a high melting point. It is also odorless, tasteless, and malleable...
isotopic contents and have found application in isotope geology and radiometric dating
Radiometric dating
Radiometric dating is a technique used to date materials such as rocks, usually based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates...
. Mn-Cr isotopic ratios reinforce the evidence from 26Al
Aluminium
Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....
and 107Pd
Palladium
Palladium is a chemical element with the chemical symbol Pd and an atomic number of 46. It is a rare and lustrous silvery-white metal discovered in 1803 by William Hyde Wollaston. He named it after the asteroid Pallas, which was itself named after the epithet of the Greek goddess Athena, acquired...
for the early history of the solar system
Solar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...
. Variations in 53Cr/52Cr and Mn/Cr ratios from several meteorite
Meteorite
A meteorite is a natural object originating in outer space that survives impact with the Earth's surface. Meteorites can be big or small. Most meteorites derive from small astronomical objects called meteoroids, but they are also sometimes produced by impacts of asteroids...
s 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
Nucleosynthesis is the process of creating new atomic nuclei from pre-existing nucleons . It is thought that the primordial nucleons themselves were formed from the quark–gluon plasma from the Big Bang as it cooled below two trillion degrees...
processes immediately before coalescence of the solar system
Solar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...
.
The isotopes of manganese range in atomic weight
Atomic weight
Atomic weight is a dimensionless physical quantity, the ratio of the average mass of atoms of an element to 1/12 of the mass of an atom of carbon-12...
from 46 u
Atomic mass unit
The unified atomic mass unit or dalton is a unit that is used for indicating mass on an atomic or molecular scale. It is defined as one twelfth of the rest mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state, and has a value of...
(46Mn) to 65 u (65Mn). The primary decay mode before the most abundant stable isotope, 55Mn, is electron capture
Electron capture
Electron capture is a process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino...
and the primary mode after is beta decay
Beta decay
In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted from an atom. There are two types of beta decay: beta minus and beta plus. In the case of beta decay that produces an electron emission, it is referred to as beta minus , while in the case of a...
.
Standard atomic mass: 54.938045(5) u
Table
| nuclide symbol |
Z(p Proton The proton is a subatomic particle with the symbol or and a positive electric charge of 1 elementary charge. One or more protons are present in the nucleus of each atom, along with neutrons. The number of protons in each atom is its atomic number.... ) |
N(n Neutron The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of... ) |
isotopic mass (u) |
half-life | decay mode(s)Abbreviations: EC: Electron capture Electron capture Electron capture is a process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino... IT: Isomeric transition Isomeric transition An isomeric transition is a radioactive decay process that involves emission of a gamma ray from an atom where the nucleus is in an excited metastable state, referred to in its excited state, as a nuclear isomer.... |
daughter isotope(s)Bold for stable isotopes |
nuclear spin |
representative isotopic composition (mole fraction) |
range of natural variation (mole fraction) |
|---|---|---|---|---|---|---|---|---|---|
| excitation energy | |||||||||
| 44Mn | 25 | 19 | 44.00687(54)# | <105 ns | p Proton decay In particle physics, proton decay is a hypothetical form of radioactive decay in which the proton decays into lighter subatomic particles, such as a neutral pion and a positron... |
43Cr | (2-)# | ||
| 45Mn | 25 | 20 | 44.99451(32)# | unknown | p | 44Cr | (7/2-)# | ||
| 46Mn | 25 | 21 | 45.98672(12)# | 37(3) ms | β+ Beta decay In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted from an atom. There are two types of beta decay: beta minus and beta plus. In the case of beta decay that produces an electron emission, it is referred to as beta minus , while in the case of a... (78%) |
46Cr | (4+) | ||
| β+, p (22%) | 45V | ||||||||
| β+, α Alpha decay Alpha decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle and thereby transforms into an atom with a mass number 4 less and atomic number 2 less... (<1%) |
42Ti | ||||||||
| β+, 2p (<1%) | 44Ti | ||||||||
| 46mMn | 150(100)# keV | 1# ms | β+ | 46Cr | 1-# | ||||
| 47Mn | 25 | 22 | 46.97610(17)# | 100(50) ms | β+ (96.6%) | 47Cr | 5/2-# | ||
| β+, p (3.4%) | 46V | ||||||||
| 48Mn | 25 | 23 | 47.96852(12) | 158.1(22) ms | β+ (99.71%) | 48Cr | 4+ | ||
| β+, p (.027%) | 47V | ||||||||
| β+, α (6×10−4%) | 44Ti | ||||||||
| 49Mn | 25 | 24 | 48.959618(26) | 382(7) ms | β+ | 49Cr | 5/2- | ||
| 50Mn | 25 | 25 | 49.9542382(11) | 283.29(8) ms | β+ | 50Cr | 0+ | ||
| 50mMn | 229(7) keV | 1.75(3) min | β+ | 50Cr | 5+ | ||||
| 51Mn | 25 | 26 | 50.9482108(11) | 46.2(1) min | β+ | 51Cr | 5/2- | ||
| 52Mn | 25 | 27 | 51.9455655(21) | 5.591(3) d | β+ | 52Cr | 6+ | ||
| 52mMn | 377.749(5) keV | 21.1(2) min | β+ (98.25%) | 52Cr | 2+ | ||||
| IT Isomeric transition An isomeric transition is a radioactive decay process that involves emission of a gamma ray from an atom where the nucleus is in an excited metastable state, referred to in its excited state, as a nuclear isomer.... (1.75%) |
52Mn | ||||||||
| 53Mn | 25 | 28 | 52.9412901(9) | 3.74(4)×106 a | EC Electron capture Electron capture is a process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino... |
53Cr | 7/2- | trace Trace radioisotope A trace radioisotope is a radioisotope that occurs naturally in trace amounts . Generally speaking, trace radioisotopes have half-lives that are short in comparison to the age of the earth, since primordial nuclides tend to occur in larger than trace amounts... |
|
| 54Mn | 25 | 29 | 53.9403589(14) | 312.03(3) d | EC 99.99% | 54Cr | 3+ | ||
| β- (2.9×10−4%) | 54Fe | ||||||||
| β+ (5.76×10−7%) | 54Cr | ||||||||
| 55Mn | 25 | 30 | 54.9380451(7) | Stable | 5/2- | 1.0000 | |||
| 56Mn | 25 | 31 | 55.9389049(7) | 2.5789(1) h | β- | 56Fe | 3+ | ||
| 57Mn | 25 | 32 | 56.9382854(20) | 85.4(18) s | β- | 57Fe | 5/2- | ||
| 58Mn | 25 | 33 | 57.93998(3) | 3.0(1) s | β- | 58Fe | 1+ | ||
| 58mMn | 71.78(5) keV | 65.2(5) s | β- (>99.9%) | 58Fe | (4)+ | ||||
| IT (<.1%) | 58Mn | ||||||||
| 59Mn | 25 | 34 | 58.94044(3) | 4.59(5) s | β- | 59Fe | (5/2)- | ||
| 60Mn | 25 | 35 | 59.94291(9) | 51(6) s | β- | 60Fe | 0+ | ||
| 60mMn | 271.90(10) keV | 1.77(2) s | β- (88.5%) | 60Fe | 3+ | ||||
| IT (11.5%) | 60Mn | ||||||||
| 61Mn | 25 | 36 | 60.94465(24) | 0.67(4) s | β- | 61Fe | (5/2)- | ||
| 62Mn | 25 | 37 | 61.94843(24) | 671(5) ms | β- (>99.9%) | 62Fe | (3+) | ||
| β-, n Neutron emission Neutron emission is a type of radioactive decay of atoms containing excess neutrons, in which a neutron is simply ejected from the nucleus. Two examples of isotopes which emit neutrons are helium-5 and beryllium-13... (<.1%) |
61Fe | ||||||||
| 62mMn | 0(150)# keV | 92(13) ms | (1+) | ||||||
| 63Mn | 25 | 38 | 62.95024(28) | 275(4) ms | β- | 63Fe | 5/2-# | ||
| 64Mn | 25 | 39 | 63.95425(29) | 88.8(25) ms | β- (>99.9%) | 64Fe | (1+) | ||
| β-, n (<.1%) | 63Fe | ||||||||
| 64mMn | 135(3) keV | >100 µs | |||||||
| 65Mn | 25 | 40 | 64.95634(58) | 92(1) ms | β- (>99.9%) | 65Fe | 5/2-# | ||
| β-, n (<.1%) | 64Fe | ||||||||
| 66Mn | 25 | 41 | 65.96108(43)# | 64.4(18) ms | β- (>99.9%) | 66Fe | |||
| β-, n (<.1%) | 65Fe | ||||||||
| 67Mn | 25 | 42 | 66.96414(54)# | 45(3) ms | β- | 67Fe | 5/2-# | ||
| 68Mn | 25 | 43 | 67.96930(64)# | 28(4) ms | |||||
| 69Mn | 25 | 44 | 68.97284(86)# | 14(4) ms | 5/2-# | ||||