Isotopes of niobium
Encyclopedia
Naturally occurring niobium
(Nb), element 41, is composed of one stable isotope
(93Nb). 93Nb is the lightest nuclide theoretically susceptible to spontaneous fission
, and although this has never been observed, it makes niobium theoretically the lightest element with no stable isotope. The first 40 elements (to zirconium) all have at least one stable nuclide which is susceptible in theory only to proton decay
.
The most stable radioisotope is 92Nb with a half-life
of 34.7 million years. This nuclide is presently the longest-lived radionuclide of all elements that has not yet been detected in nature as primordial isotope. (The nuclide with the next longest half-life, 244Pu
with half-life 80 million years, has been detected, and is thus primordial).
The next longest-lived niobium nuclides are 94Nb (half-life: 20,300 years), and 91Nb with a half-life of 680 years. There is also a meta state at 31 keV
whose half-life is 16.13 years. Twenty three other radioisotopes have been characterized. Most of these have half-lives that are less than two hours except 95Nb (35 days), 96Nb (23.4 hours) and 90Nb (14.6 hours). The primary decay mode before the stable 93Nb is electron capture
and the primary mode after is beta emission with some neutron emission
occurring in 104-110Nb.
Only 95Nb (35 days) and 97Nb (72 minutes) and heavier isotopes (half-lives in seconds) are fission products in significant quantity, as the other isotopes are shadowed by stable or very long-lived (93Zr) isotopes of the preceding element zirconium
from production via beta decay
of neutron-rich fission fragments. 95Nb is the decay product
of 95Zr (64 days), so disappearance of 95Nb in used nuclear fuel is slower than would be expected from its own 35 day halflife alone. Tiny amounts of the other isotopes may be produced as direct fission products.
Niobium's standard atomic mass is 92.90638(2) u.
Niobium
Niobium or columbium , is a chemical element with the symbol Nb and atomic number 41. It's a soft, grey, ductile transition metal, which is often found in the pyrochlore mineral, the main commercial source for niobium, and columbite...
(Nb), element 41, is composed of one 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...
(93Nb). 93Nb is the lightest nuclide theoretically susceptible to spontaneous fission
Spontaneous fission
Spontaneous fission is a form of radioactive decay characteristic of very heavy isotopes. Because the nuclear binding energy reaches a maximum at a nuclear mass greater than about 60 atomic mass units , spontaneous breakdown into smaller nuclei and single particles becomes possible at heavier masses...
, and although this has never been observed, it makes niobium theoretically the lightest element with no stable isotope. The first 40 elements (to zirconium) all have at least one stable nuclide which is susceptible in theory only to proton decay
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...
.
The most stable radioisotope is 92Nb 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 34.7 million years. This nuclide is presently the longest-lived radionuclide of all elements that has not yet been detected in nature as primordial isotope. (The nuclide with the next longest half-life, 244Pu
Plutonium-244
Plutonium-244 is an isotope of plutonium that has a halflife of 80 million years. This is longer than any of the other isotopes of plutonium and longer than any actinide except for the three naturally abundant ones uranium-235 , uranium-238, and thorium-232...
with half-life 80 million years, has been detected, and is thus primordial).
The next longest-lived niobium nuclides are 94Nb (half-life: 20,300 years), and 91Nb with a half-life of 680 years. There is also a meta state at 31 keV
Electronvolt
In physics, the electron volt is a unit of energy equal to approximately joule . By definition, it is equal to the amount of kinetic energy gained by a single unbound electron when it accelerates through an electric potential difference of one volt...
whose half-life is 16.13 years. Twenty three other radioisotopes have been characterized. Most of these have half-lives that are less than two hours except 95Nb (35 days), 96Nb (23.4 hours) and 90Nb (14.6 hours). The primary decay mode before the stable 93Nb 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 emission with some neutron emission
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...
occurring in 104-110Nb.
Only 95Nb (35 days) and 97Nb (72 minutes) and heavier isotopes (half-lives in seconds) are fission products in significant quantity, as the other isotopes are shadowed by stable or very long-lived (93Zr) isotopes of the preceding element zirconium
Zirconium
Zirconium is a chemical element with the symbol Zr and atomic number 40. The name of zirconium is taken from the mineral zircon. Its atomic mass is 91.224. It is a lustrous, grey-white, strong transition metal that resembles titanium...
from production via 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...
of neutron-rich fission fragments. 95Nb is the decay product
Decay product
In nuclear physics, a decay product is the remaining nuclide left over from radioactive decay. Radioactive decay often involves a sequence of steps...
of 95Zr (64 days), so disappearance of 95Nb in used nuclear fuel is slower than would be expected from its own 35 day halflife alone. Tiny amounts of the other isotopes may be produced as direct fission products.
Niobium's standard atomic mass is 92.90638(2) 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, bold italic for near-stable isotopes (half-life longer than the age of the universe Age of the universe The age of the universe is the time elapsed since the Big Bang posited by the most widely accepted scientific model of cosmology. The best current estimate of the age of the universe is 13.75 ± 0.13 billion years within the Lambda-CDM concordance model... ) |
nuclear spin |
representative isotopic composition (mole fraction) |
range of natural variation (mole fraction) |
|---|---|---|---|---|---|---|---|---|---|
| excitation energy | |||||||||
| 81Nb | 41 | 40 | 80.94903(161)# | <44 ns | 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... , p Proton emission Proton emission is a type of radioactive decay in which a proton is ejected from a nucleus. Proton emission can occur from high-lying excited states in a nucleus following a beta decay, in which case the process is known as beta-delayed proton emission, or can occur from the ground state of very... |
80Y | 3/2-# | ||
| p | 80Zr | ||||||||
| β+ | 81Zr | ||||||||
| 82Nb | 41 | 41 | 81.94313(32)# | 51(5) ms | β+ | 82Zr | 0+ | ||
| 83Nb | 41 | 42 | 82.93671(34) | 4.1(3) s | β+ | 83Zr | (5/2+) | ||
| 84Nb | 41 | 43 | 83.93357(32)# | 9.8(9) s | β+ (>99.9%) | 84Zr | 3+ | ||
| β+, p (<.1%) | 83Y | ||||||||
| 84mNb | 338(10) keV | 103(19) ns | (5-) | ||||||
| 85Nb | 41 | 44 | 84.92791(24) | 20.9(7) s | β+ | 85Zr | (9/2+) | ||
| 85mNb | 759.0(10) keV | 12(5) s | (1/2-) | ||||||
| 86Nb | 41 | 45 | 85.92504(9) | 88(1) s | β+ | 86Zr | (6+) | ||
| 86mNb | 250(160)# keV | 56(8) s | β+ | 86Zr | high | ||||
| 87Nb | 41 | 46 | 86.92036(7) | 3.75(9) min | β+ | 87Zr | (1/2-) | ||
| 87mNb | 3.84(14) keV | 2.6(1) min | β+ | 87Zr | (9/2+)# | ||||
| 88Nb | 41 | 47 | 87.91833(11) | 14.55(6) min | β+ | 88Zr | (8+) | ||
| 88mNb | 40(140) keV | 7.8(1) min | β+ | 88Zr | (4-) | ||||
| 89Nb | 41 | 48 | 88.913418(29) | 2.03(7) h | β+ | 89Zr | (9/2+) | ||
| 89mNb | 0(30)# keV | 1.10(3) h | β+ | 89Zr | (1/2)- | ||||
| 90Nb | 41 | 49 | 89.911265(5) | 14.60(5) h | β+ | 90Zr | 8+ | ||
| 90m1Nb | 122.370(22) keV | 63(2) µs | 6+ | ||||||
| 90m2Nb | 124.67(25) keV | 18.81(6) s | 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.... |
90Nb | 4- | ||||
| 90m3Nb | 171.10(10) keV | <1 µs | 7+ | ||||||
| 90m4Nb | 382.01(25) keV | 6.19(8) ms | 1+ | ||||||
| 90m5Nb | 1880.21(20) keV | 472(13) ns | (11-) | ||||||
| 91Nb | 41 | 50 | 90.906996(4) | 680(130) 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... (99.98%) |
91Zr | 9/2+ | ||
| β+ (.013%) | 91Zr | ||||||||
| 91m1Nb | 104.60(5) keV | 60.86(22) d | IT (93%) | 91Nb | 1/2- | ||||
| EC (7%) | 91Zr | ||||||||
| β+ (.0028%) | 91Zr | ||||||||
| 91m2Nb | 2034.35(19) keV | 3.76(12) µs | (17/2-) | ||||||
| 92Nb | 41 | 51 | 91.907194(3) | 3.47(24)×107 aLongest 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 all non-primordial Primordial nuclide In geochemistry and geonuclear physics, primordial nuclides or primordial isotopes are nuclides found on the earth that have existed in their current form since before Earth was formed. Only 288 such nuclides are known... radionuclide Radionuclide A radionuclide is an atom with an unstable nucleus, which is a nucleus characterized by excess energy available to be imparted either to a newly created radiation particle within the nucleus or to an atomic electron. The radionuclide, in this process, undergoes radioactive decay, and emits gamma... s |
β+ (99.95%) | 92Zr | (7)+ | ||
| β- (.05%) | 92Mo | ||||||||
| 92m1Nb | 135.5(4) keV | 10.15(2) d | β+ | 92Zr | (2)+ | ||||
| 92m2Nb | 225.7(4) keV | 5.9(2) µs | (2)- | ||||||
| 92m3Nb | 2203.3(4) keV | 167(4) ns | (11-) | ||||||
| 93Nb | 41 | 52 | 92.9063781(26) | Observationally StableTheoretically capable of spontaneous fission Spontaneous fission Spontaneous fission is a form of radioactive decay characteristic of very heavy isotopes. Because the nuclear binding energy reaches a maximum at a nuclear mass greater than about 60 atomic mass units , spontaneous breakdown into smaller nuclei and single particles becomes possible at heavier masses... , lightest nuclide so capable |
9/2+ | 1.0000 | |||
| 93mNb | 30.77(2) keV | 16.13(14) a | IT | 93Nb | 1/2- | ||||
| 94Nb | 41 | 53 | 93.9072839(26) | 2.03(16)×104 a | β- | 94Mo | (6)+ | ||
| 94mNb | 40.902(12) keV | 6.263(4) min | IT (99.5%) | 94Nb | 3+ | ||||
| β- (.5%) | 94Mo | ||||||||
| 95Nb | 41 | 54 | 94.9068358(21) | 34.991(6) d | β- | 95Mo | 9/2+ | ||
| 95mNb | 235.690(20) keV | 3.61(3) d | IT (94.4%) | 95Nb | 1/2- | ||||
| β- (5.6%) | 95Mo | ||||||||
| 96Nb | 41 | 55 | 95.908101(4) | 23.35(5) h | β- | 96Mo | 6+ | ||
| 97Nb | 41 | 56 | 96.9080986(27) | 72.1(7) min | β- | 97Mo | 9/2+ | ||
| 97mNb | 743.35(3) keV | 52.7(18) s | IT | 97Nb | 1/2- | ||||
| 98Nb | 41 | 57 | 97.910328(6) | 2.86(6) s | β- | 98Mo | 1+ | ||
| 98mNb | 84(4) keV | 51.3(4) min | β- (99.9%) | 98Mo | (5+) | ||||
| IT (.1%) | 98Nb | ||||||||
| 99Nb | 41 | 58 | 98.911618(14) | 15.0(2) s | β- | 99Mo | 9/2+ | ||
| 99mNb | 365.29(14) keV | 2.6(2) min | β- (96.2%) | 99Mo | 1/2- | ||||
| IT (3.8%) | 99Nb | ||||||||
| 100Nb | 41 | 59 | 99.914182(28) | 1.5(2) s | β- | 100Mo | 1+ | ||
| 100mNb | 470(40) keV | 2.99(11) s | β- | 100Mo | (4+,5+) | ||||
| 101Nb | 41 | 60 | 100.915252(20) | 7.1(3) s | β- | 101Mo | (5/2#)+ | ||
| 102Nb | 41 | 61 | 101.91804(4) | 1.3(2) s | β- | 102Mo | 1+ | ||
| 102mNb | 130(50) keV | 4.3(4) s | β- | 102Mo | high | ||||
| 103Nb | 41 | 62 | 102.91914(7) | 1.5(2) s | β- | 103Mo | (5/2+) | ||
| 104Nb | 41 | 63 | 103.92246(11) | 4.9(3) s | β- (99.94%) | 104Mo | (1+) | ||
| 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... (.06%) |
103Mo | ||||||||
| 104mNb | 220(120) keV | 940(40) ms | β- (99.95%) | 104Mo | high | ||||
| β-, n (.05%) | 103Mo | ||||||||
| 105Nb | 41 | 64 | 104.92394(11) | 2.95(6) s | β- (98.3%) | 105Mo | (5/2+)# | ||
| β-, n (1.7%) | 104Mo | ||||||||
| 106Nb | 41 | 65 | 105.92797(21)# | 920(40) ms | β- (95.5%) | 106Mo | 2+# | ||
| β-, n (4.5%) | 105Mo | ||||||||
| 107Nb | 41 | 66 | 106.93031(43)# | 300(9) ms | β- (94%) | 107Mo | 5/2+# | ||
| β-, n (6%) | 106Mo | ||||||||
| 108Nb | 41 | 67 | 107.93484(32)# | 0.193(17) s | β- (93.8%) | 108Mo | (2+) | ||
| β-, n (6.2%) | 107Mo | ||||||||
| 109Nb | 41 | 68 | 108.93763(54)# | 190(30) ms | β- (69%) | 109Mo | 5/2+# | ||
| β-, n (69%) | 108Mo | ||||||||
| 110Nb | 41 | 69 | 109.94244(54)# | 170(20) ms | β- (60%) | 110Mo | 2+# | ||
| β-, n (40%) | 109Mo | ||||||||
| 111Nb | 41 | 70 | 110.94565(54)# | 80# ms [>300 ns] | 5/2+# | ||||
| 112Nb | 41 | 71 | 111.95083(75)# | 60# ms [>300 ns] | 2+# | ||||
| 113Nb | 41 | 72 | 112.95470(86)# | 30# ms [>300 ns] | 5/2+# | ||||