Naturally occurring

niobium Niobium is a chemical element with chemical symbol Nb (formerly columbium, Cb) and atomic number 41. It is a light grey, crystalline, and ductile transition metal. Pure niobium has a Mohs hardness rating similar to pure titanium, and it has s ...

(₄₁Nb) is composed of one

stable A stable is a building in which livestock, especially horses, are kept. It most commonly means a building that is divided into separate stalls for individual animals and livestock. There are many different types of stables in use today; the ...

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 num ...

(⁹³Nb). The most stable

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 ...

is ⁹²Nb 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 ...

of 34.7 million years. The next longest-lived niobium isotopes are ⁹⁴Nb (half-life: 20,300 years) and ⁹¹Nb with a half-life of 680 years. There is also a

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 ...

of ⁹³Nb at 31

keV Kev can refer to: Given name * Kev Adams, French comedian, actor, screenwriter and film producer born Kevin Smadja in 1991 * Kevin Kev Carmody (born 1946), Indigenous Australian singer-songwriter * Kev Coghlan (born 1988), Scottish Grand Prix moto ...

whose half-life is 16.13 years. Twenty-seven 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 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 consid ...

before stable ⁹³Nb 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. ...

and the primary mode after is

beta emission 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 exam ...

with some

neutron emission Neutron emission is a mode of radioactive decay in which one or more neutrons are ejected from a nucleus. It occurs in the most neutron-rich/proton-deficient nuclides, and also from excited states of other nuclides as in photoneutron emission and ...

occurring in ^104–110Nb. Only ⁹⁵Nb (35 days) and ⁹⁷Nb (72 minutes) and heavier isotopes (half-lives in seconds) are

fission products Nuclear fission products are the atomic fragments left after a large atomic nucleus undergoes nuclear fission. Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons, the release ...

in significant quantity, as the other isotopes are shadowed by stable or very long-lived ( ⁹³Zr) isotopes of the preceding element

zirconium Zirconium is a chemical element with the symbol Zr and atomic number 40. The name ''zirconium'' is taken from the name of the mineral zircon, the most important source of zirconium. The word is related to Persian '' zargun'' (zircon; ''zar-gun'' ...

from production via

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 ...

of neutron-rich fission fragments. ⁹⁵Nb is the

decay product In nuclear physics, a decay product (also known as a daughter product, daughter isotope, radio-daughter, or daughter nuclide) is the remaining nuclide left over from radioactive decay. Radioactive decay often proceeds via a sequence of steps ( ...

of ⁹⁵Zr (64 days), so disappearance of ⁹⁵Nb in

used nuclear fuel Spent nuclear fuel, occasionally called used nuclear fuel, is nuclear fuel that has been irradiated in a nuclear reactor (usually at a nuclear power plant). It is no longer useful in sustaining a nuclear reaction in an ordinary thermal reactor and ...

is slower than would be expected from its own 35-day half-life alone. Small amounts of other isotopes may be produced as direct fission products.

List of isotopes

, - , rowspan=3, ⁸¹Nb , rowspan=3 style="text-align:right" , 41 , rowspan=3 style="text-align:right" , 40 , rowspan=3, 80.94903(161)# , rowspan=3, <44 ns , β⁺, p , ⁸⁰Y , rowspan=3, 3/2−# , rowspan=3, , rowspan=3, , - , p , ⁸⁰Zr , - , β⁺ , ⁸¹Zr , - , ⁸²Nb , style="text-align:right" , 41 , style="text-align:right" , 41 , 81.94313(32)# , 51(5) ms , β⁺ , ⁸²Zr , 0+ , , , - , ⁸³Nb , style="text-align:right" , 41 , style="text-align:right" , 42 , 82.93671(34) , 4.1(3) s , β⁺ , ⁸³Zr , (5/2+) , , , - , rowspan=2, ⁸⁴Nb , rowspan=2 style="text-align:right" , 41 , rowspan=2 style="text-align:right" , 43 , rowspan=2, 83.93357(32)# , rowspan=2, 9.8(9) s , β⁺ (>99.9%) , ⁸⁴Zr , rowspan=2, 3+ , rowspan=2, , rowspan=2, , - , β⁺, p (<.1%) , ⁸³Y , - , style="text-indent:1em" , ^84mNb , colspan="3" style="text-indent:2em" , 338(10) keV , 103(19) ns , , , (5−) , , , - , ⁸⁵Nb , style="text-align:right" , 41 , style="text-align:right" , 44 , 84.92791(24) , 20.9(7) s , β⁺ , ⁸⁵Zr , (9/2+) , , , - , style="text-indent:1em" , ^85mNb , colspan="3" style="text-indent:2em" , 759.0(10) keV , 12(5) s , , , (1/2−) , , , - , ⁸⁶Nb , style="text-align:right" , 41 , style="text-align:right" , 45 , 85.92504(9) , 88(1) s , β⁺ , ⁸⁶Zr , (6+) , , , - , style="text-indent:1em" , ^86mNb , colspan="3" style="text-indent:2em" , 250(160)# keV , 56(8) s , β⁺ , ⁸⁶Zr , high , , , - , ⁸⁷Nb , style="text-align:right" , 41 , style="text-align:right" , 46 , 86.92036(7) , 3.75(9) min , β⁺ , ⁸⁷Zr , (1/2−) , , , - , style="text-indent:1em" , ^87mNb , colspan="3" style="text-indent:2em" , 3.84(14) keV , 2.6(1) min , β⁺ , ⁸⁷Zr , (9/2+)# , , , - , ⁸⁸Nb , style="text-align:right" , 41 , style="text-align:right" , 47 , 87.91833(11) , 14.55(6) min , β⁺ , ⁸⁸Zr , (8+) , , , - , style="text-indent:1em" , ^88mNb , colspan="3" style="text-indent:2em" , 40(140) keV , 7.8(1) min , β⁺ , ⁸⁸Zr , (4−) , , , - , ⁸⁹Nb , style="text-align:right" , 41 , style="text-align:right" , 48 , 88.913418(29) , 2.03(7) h , β⁺ , ⁸⁹Zr , (9/2+) , , , - , style="text-indent:1em" , ^89mNb , colspan="3" style="text-indent:2em" , 0(30)# keV , 1.10(3) h , β⁺ , ⁸⁹Zr , (1/2)− , , , - , ⁹⁰Nb , style="text-align:right" , 41 , style="text-align:right" , 49 , 89.911265(5) , 14.60(5) h , β⁺ , ⁹⁰Zr , 8+ , , , - , style="text-indent:1em" , ^90m1Nb , colspan="3" style="text-indent:2em" , 122.370(22) keV , 63(2) μs , , , 6+ , , , - , style="text-indent:1em" , ^90m2Nb , colspan="3" style="text-indent:2em" , 124.67(25) keV , 18.81(6) s , IT , ⁹⁰Nb , 4- , , , - , style="text-indent:1em" , ^90m3Nb , colspan="3" style="text-indent:2em" , 171.10(10) keV , <1 μs , , , 7+ , , , - , style="text-indent:1em" , ^90m4Nb , colspan="3" style="text-indent:2em" , 382.01(25) keV , 6.19(8) ms , , , 1+ , , , - , style="text-indent:1em" , ^90m5Nb , colspan="3" style="text-indent:2em" , 1880.21(20) keV , 472(13) ns , , , (11−) , , , - , rowspan=2, ⁹¹Nb , rowspan=2 style="text-align:right" , 41 , rowspan=2 style="text-align:right" , 50 , rowspan=2, 90.906996(4) , rowspan=2, 680(130) a , EC (99.98%) , ⁹¹Zr , rowspan=2, 9/2+ , rowspan=2, , rowspan=2, , - , β⁺ (.013%) , ⁹¹Zr , - , rowspan=3 style="text-indent:1em" , ^91m1Nb , rowspan=3 colspan="3" style="text-indent:2em" , 104.60(5) keV , rowspan=3, 60.86(22) d , IT (93%) , ⁹¹Nb , rowspan=3, 1/2− , rowspan=3, , rowspan=3, , - , EC (7%) , ⁹¹Zr , - , β⁺ (.0028%) , ⁹¹Zr , - , style="text-indent:1em" , ^91m2Nb , colspan="3" style="text-indent:2em" , 2034.35(19) keV , 3.76(12) μs , , , (17/2−) , , , - , rowspan=2, ⁹²Nb , rowspan=2 style="text-align:right" , 41 , rowspan=2 style="text-align:right" , 51 , rowspan=2, 91.907194(3) , rowspan=2, 3.47(24)×10⁷ a , β⁺ (99.95%) , ⁹²Zr , rowspan=2, (7)+ , rowspan=2, , rowspan=2, , - , β⁻ (.05%) , ⁹²Mo , - , style="text-indent:1em" , ^92m1Nb , colspan="3" style="text-indent:2em" , 135.5(4) keV , 10.15(2) d , β⁺ , ⁹²Zr , (2)+ , , , - , style="text-indent:1em" , ^92m2Nb , colspan="3" style="text-indent:2em" , 225.7(4) keV , 5.9(2) μs , , , (2)− , , , - , style="text-indent:1em" , ^92m3Nb , colspan="3" style="text-indent:2em" , 2203.3(4) keV , 167(4) ns , , , (11−) , , , - , ⁹³Nb , style="text-align:right" , 41 , style="text-align:right" , 52 , 92.9063781(26) , colspan=3 align=center, StableTheoretically capable of

spontaneous fission Spontaneous fission (SF) is a form of radioactive decay that is found only in very heavy chemical elements. The nuclear binding energy of the elements reaches its maximum at an atomic mass number of about 56 (e.g., iron-56); spontaneous breakd ...

, lightest nuclide so capable , 9/2+ , 1.0000 , , - , style="text-indent:1em" , ^93mNb , colspan="3" style="text-indent:2em" , 30.77(2) keV , 16.13(14) a , IT , ⁹³Nb , 1/2− , , , - , ⁹⁴Nb , style="text-align:right" , 41 , style="text-align:right" , 53 , 93.9072839(26) , 2.03(16)×10⁴ a , β⁻ , ⁹⁴Mo , (6)+ , , , - , rowspan=2 style="text-indent:1em" , ^94mNb , rowspan=2 colspan="3" style="text-indent:2em" , 40.902(12) keV , rowspan=2, 6.263(4) min , IT (99.5%) , ⁹⁴Nb , rowspan=2, 3+ , rowspan=2, , rowspan=2, , - , β⁻ (.5%) , ⁹⁴Mo , - , ⁹⁵Nb , style="text-align:right" , 41 , style="text-align:right" , 54 , 94.9068358(21) , 34.991(6) d , β⁻ , ⁹⁵Mo , 9/2+ , , , - , rowspan=2 style="text-indent:1em" , ^95mNb , rowspan=2 colspan="3" style="text-indent:2em" , 235.690(20) keV , rowspan=2, 3.61(3) d , IT (94.4%) , ⁹⁵Nb , rowspan=2, 1/2− , rowspan=2, , rowspan=2, , - , β⁻ (5.6%) , ⁹⁵Mo , - , ⁹⁶Nb , style="text-align:right" , 41 , style="text-align:right" , 55 , 95.908101(4) , 23.35(5) h , β⁻ , ⁹⁶Mo , 6+ , , , - , ⁹⁷Nb , style="text-align:right" , 41 , style="text-align:right" , 56 , 96.9080986(27) , 72.1(7) min , β⁻ , ⁹⁷Mo , 9/2+ , , , - , style="text-indent:1em" , ^97mNb , colspan="3" style="text-indent:2em" , 743.35(3) keV , 52.7(18) s , IT , ⁹⁷Nb , 1/2− , , , - , ⁹⁸Nb , style="text-align:right" , 41 , style="text-align:right" , 57 , 97.910328(6) , 2.86(6) s , β⁻ , ⁹⁸Mo , 1+ , , , - , rowspan=2 style="text-indent:1em" , ^98mNb , rowspan=2 colspan="3" style="text-indent:2em" , 84(4) keV , rowspan=2, 51.3(4) min , β⁻ (99.9%) , ⁹⁸Mo , rowspan=2, (5+) , rowspan=2, , rowspan=2, , - , IT (.1%) , ⁹⁸Nb , - , ⁹⁹Nb , style="text-align:right" , 41 , style="text-align:right" , 58 , 98.911618(14) , 15.0(2) s , β⁻ , ⁹⁹Mo , 9/2+ , , , - , rowspan=2 style="text-indent:1em" , ^99mNb , rowspan=2 colspan="3" style="text-indent:2em" , 365.29(14) keV , rowspan=2, 2.6(2) min , β⁻ (96.2%) , ⁹⁹Mo , rowspan=2, 1/2− , rowspan=2, , rowspan=2, , - , IT (3.8%) , ⁹⁹Nb , - , ¹⁰⁰Nb , style="text-align:right" , 41 , style="text-align:right" , 59 , 99.914182(28) , 1.5(2) s , β⁻ , ''¹⁰⁰Mo'' , 1+ , , , - , style="text-indent:1em" , ^100mNb , colspan="3" style="text-indent:2em" , 470(40) keV , 2.99(11) s , β⁻ , ''¹⁰⁰Mo'' , (4+, 5+) , , , - , ¹⁰¹Nb , style="text-align:right" , 41 , style="text-align:right" , 60 , 100.915252(20) , 7.1(3) s , β⁻ , ¹⁰¹Mo , (5/2#)+ , , , - , ¹⁰²Nb , style="text-align:right" , 41 , style="text-align:right" , 61 , 101.91804(4) , 1.3(2) s , β⁻ , ¹⁰²Mo , 1+ , , , - , style="text-indent:1em" , ^102mNb , colspan="3" style="text-indent:2em" , 130(50) keV , 4.3(4) s , β⁻ , ¹⁰²Mo , high , , , - , ¹⁰³Nb , style="text-align:right" , 41 , style="text-align:right" , 62 , 102.91914(7) , 1.5(2) s , β⁻ , ¹⁰³Mo , (5/2+) , , , - , rowspan=2, ¹⁰⁴Nb , rowspan=2 style="text-align:right" , 41 , rowspan=2 style="text-align:right" , 63 , rowspan=2, 103.92246(11) , rowspan=2, 4.9(3) s , β⁻ (99.94%) , ¹⁰⁴Mo , rowspan=2, (1+) , rowspan=2, , rowspan=2, , - , β⁻, n (.06%) , ¹⁰³Mo , - , rowspan=2 style="text-indent:1em" , ^104mNb , rowspan=2 colspan="3" style="text-indent:2em" , 220(120) keV , rowspan=2, 940(40) ms , β⁻ (99.95%) , ¹⁰⁴Mo , rowspan=2, high , rowspan=2, , rowspan=2, , - , β⁻, n (.05%) , ¹⁰³Mo , - , rowspan=2, ¹⁰⁵Nb , rowspan=2 style="text-align:right" , 41 , rowspan=2 style="text-align:right" , 64 , rowspan=2, 104.92394(11) , rowspan=2, 2.95(6) s , β⁻ (98.3%) , ¹⁰⁵Mo , rowspan=2, (5/2+)# , rowspan=2, , rowspan=2, , - , β⁻, n (1.7%) , ¹⁰⁴Mo , - , rowspan=2, ¹⁰⁶Nb , rowspan=2 style="text-align:right" , 41 , rowspan=2 style="text-align:right" , 65 , rowspan=2, 105.92797(21)# , rowspan=2, 920(40) ms , β⁻ (95.5%) , ¹⁰⁶Mo , rowspan=2, 2+# , rowspan=2, , rowspan=2, , - , β⁻, n (4.5%) , ¹⁰⁵Mo , - , rowspan=2, ¹⁰⁷Nb , rowspan=2 style="text-align:right" , 41 , rowspan=2 style="text-align:right" , 66 , rowspan=2, 106.93031(43)# , rowspan=2, 300(9) ms , β⁻ (94%) , ¹⁰⁷Mo , rowspan=2, 5/2+# , rowspan=2, , rowspan=2, , - , β⁻, n (6%) , ¹⁰⁶Mo , - , rowspan=2, ¹⁰⁸Nb , rowspan=2 style="text-align:right" , 41 , rowspan=2 style="text-align:right" , 67 , rowspan=2, 107.93484(32)# , rowspan=2, 0.193(17) s , β⁻ (93.8%) , ¹⁰⁸Mo , rowspan=2, (2+) , rowspan=2, , rowspan=2, , - , β⁻, n (6.2%) , ¹⁰⁷Mo , - , rowspan=2, ¹⁰⁹Nb , rowspan=2 style="text-align:right" , 41 , rowspan=2 style="text-align:right" , 68 , rowspan=2, 108.93763(54)# , rowspan=2, 190(30) ms , β⁻ (69%) , ¹⁰⁹Mo , rowspan=2, 5/2+# , rowspan=2, , rowspan=2, , - , β⁻, n (69%) , ¹⁰⁸Mo , - , rowspan=2, ¹¹⁰Nb , rowspan=2 style="text-align:right" , 41 , rowspan=2 style="text-align:right" , 69 , rowspan=2, 109.94244(54)# , rowspan=2, 170(20) ms , β⁻ (60%) , ¹¹⁰Mo , rowspan=2, 2+# , rowspan=2, , rowspan=2, , - , β⁻, n (40%) , ¹⁰⁹Mo , - , ¹¹¹Nb , style="text-align:right" , 41 , style="text-align:right" , 70 , 110.94565(54)# , 80# ms 300 ns, , , 5/2+# , , , - , ¹¹²Nb , style="text-align:right" , 41 , style="text-align:right" , 71 , 111.95083(75)# , 60# ms 300 ns, , , 2+# , , , - , ¹¹³Nb , style="text-align:right" , 41 , style="text-align:right" , 72 , 112.95470(86)# , 30# ms 300 ns, , , 5/2+# , , , - , ¹¹⁴Nb , style="text-align:right" , 41 , style="text-align:right" , 73 , , , , , , , , - , ¹¹⁵Nb , style="text-align:right" , 41 , style="text-align:right" , 74 , , , , , , , , - , ¹¹⁶Nb , style="text-align:right" , 41 , style="text-align:right" , 75 , , , , , , , , - , ¹¹⁷Nb , style="text-align:right" , 41 , style="text-align:right" , 76 , , , , , , ,

Niobium-92

Niobium-92 is an

extinct radionuclide An extinct radionuclide is a radionuclide that was formed by nucleosynthesis before the formation of the Solar System, about 4.6 billion years ago, but has since decayed to virtually zero abundance and is no longer detectable as a primordial nuc ...

with a half-life of 34.7 million years, decaying predominantly via β⁺ decay. Its abundance relative to the stable ⁹³Nb in the early Solar System, estimated at 1.7×10⁻⁵, has been measured to investigate the origin of

p-nuclei p-nuclei (''p'' stands for proton-rich) are certain proton-rich, naturally occurring isotopes of some elements between selenium and mercury inclusive which cannot be produced in either the s- or the r-process. Definition The classical, gro ...

. This isotope, along with ⁹⁴Nb, has been detected in refined samples of terrestrial niobium and may originate from bombardment by

cosmic ray 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 own ...

muon A muon ( ; from the Greek letter mu (μ) used to represent it) is an elementary particle similar to the electron, with an electric charge of −1 '' e'' and a spin of , but with a much greater mass. It is classified as a lepton. As w ...

s in Earth's crust.

References

* Isotope masses from: ** * Isotopic compositions and standard atomic masses from: ** ** * Half-life, spin, and isomer data selected from the following sources. ** ** ** {{Authority control Niobium

Niobium Niobium is a chemical element with chemical symbol Nb (formerly columbium, Cb) and atomic number 41. It is a light grey, crystalline, and ductile transition metal. Pure niobium has a Mohs hardness rating similar to pure titanium, and it has s ...