Природниот ниобиум (41Nb) е составен од еден стабилен изотоп(93Nb). Најстабилен радиоизотоп е 92Nb со период на полураспад од 34.7 милиони години. Следните најдолговечни изотопи на ниобиум се 94Nb (период на полураспад: 20,300 години) и 91Nb со полуживот од 680 години. Постои и мета состојба на 93Nb на 31 keV чиј период на полураспад е 16,13 години. Дваесет и седум други радиоизотопи се карактеризираат. Повеќето од нив имаат полуживот кој е помал од два часа, освен 95Nb (35 дена), 96Nb (23.4 часа) на 90Nb (14.6 часа). Примарниот режим на распаѓање пред стабилен 93Nb е зафаќање на електрони, а примарниот режим потоа е бета емисија со одредена емисија на неутрони што се јавува во 104–110Nb.
Само 95Nb (35 дена) и 97Nb (72 минути) и потешки изотопи (период на полураспад во секунди) се производи на фисија во значителна количина, бидејќи другите изотопи се засенчени од стабилни или многу долготрајни ( <sup id="mwLw">93</sup> Zr ) изотопи на претходниот елемент циркониум богат со фрагменти од производство на фисија. 95Nb е распаден производ од 95Zr (64 дена), така што исчезнувањето на 95 Nb во искористеното јадрено гориво е побавно отколку што би се очекувало само од сопствениот период на полураспад од 35 дена. Мали количества на други изотопи може да се произведат како производи за директна фисија.
Список на изотопи
|-id=Niobium-82 | 82Nb | style="text-align:right" | 41 | style="text-align:right" | 41 | 81.94438(32) | 51(5) ms | β+ | 82Zr | (0+) | |-id=Niobium-82m | style="text-indent:1em" | 82mNb | colspan="3" style="text-indent:2em" | 1180(1) keV | 93(20) ns | IT | 82Nb | (5+) | |-id=Niobium-83 | 83Nb | style="text-align:right" | 41 | style="text-align:right" | 42 | 82.93815(17) | 3.9(2) s | β+ | 83Zr | 9/2+# | |-id=Niobium-84 | 84Nb | style="text-align:right" | 41 | style="text-align:right" | 43 | 83.93430571(43) | 9.8(9) s | β+ | 84Zr | (1+) | |-id=Niobium-84m1 | style="text-indent:1em" | 84m1Nb | colspan="3" style="text-indent:2em" | 48(1) keV | 176(46) ns | IT | 84Nb | (3+) | |-id=Niobium-84m2 | style="text-indent:1em" | 84m2Nb | colspan="3" style="text-indent:2em" | 337.7(4) keV | 92(5) ns | IT | 84Nb | (5−) | |-id=Niobium-85 | 85Nb | style="text-align:right" | 41 | style="text-align:right" | 44 | 84.9288458(44) | 20.5(7) s | β+ | 85Zr | 9/2+# | |-id=Niobium-85m | rowspan=2 style="text-indent:1em" | 85mNb | rowspan=2 colspan="3" style="text-indent:2em" | 150(80)# keV | rowspan=2|3.3(9) s | IT (?%) | 85Nb | rowspan=2|(1/2−) | rowspan=2| |- | β+ (?%) | 85Zr |-id=Niobium-86 | 86Nb | style="text-align:right" | 41 | style="text-align:right" | 45 | 85.9257815(59) | 88(1) s | β+ | 86Zr | (6+) | |-id=Niobium-86m | style="text-indent:1em" | 86mNbOrder of ground state and isomer is uncertain. | colspan="3" style="text-indent:2em" | 150(100)# keV | 20# s | β+ | 86Zr | (0−,1−,2−) | |-id=Niobium-87 | 87Nb | style="text-align:right" | 41 | style="text-align:right" | 46 | 86.9206925(73) | 3.7(1) min | β+ | 87Zr | (1/2)− | |-id=Niobium-87m | style="text-indent:1em" | 87mNb | colspan="3" style="text-indent:2em" | 3.9(1) keV | 2.6(1) min | β+ | 87Zr | (9/2)+ | |-id=Niobium-88 | 88Nb | style="text-align:right" | 41 | style="text-align:right" | 47 | 87.918226(62) | 14.50(11) min | β+ | 88Zr | (8+) | |-id=Niobium-88m | style="text-indent:1em" | 88mNb | colspan="3" style="text-indent:2em" | 130(120) keV | 7.7(1) min | β+ | 88Zr | (4−) | |-id=Niobium-89 | 89Nb | style="text-align:right" | 41 | style="text-align:right" | 48 | 88.913445(25) | 2.03(7) h | β+ | 89Zr | (9/2+) | |-id=Niobium-89m | style="text-indent:1em" | 89mNb | colspan="3" style="text-indent:2em" | 0(30)# keV | 1.10(3) h | β+ | 89Zr | (1/2)− | |-id=Niobium-90 | 90Nb | style="text-align:right" | 41 | style="text-align:right" | 49 | 89.9112592(36) | 14.60(5) h | β+ | 90Zr | 8+ | |-id=Niobium-90m1 | style="text-indent:1em" | 90m1Nb | colspan="3" style="text-indent:2em" | 122.370(22) keV | 63(2) μs | IT | 90Nb | 6+ | |-id=Niobium-90m2 | style="text-indent:1em" | 90m2Nb | colspan="3" style="text-indent:2em" | 124.67(25) keV | 18.81(6) s | IT | 90Nb | 4- | |-id=Niobium-90m3 | style="text-indent:1em" | 90m3Nb | colspan="3" style="text-indent:2em" | 171.10(10) keV | <1 μs | IT | 90Nb | 7+ | |-id=Niobium-90m4 | style="text-indent:1em" | 90m4Nb | colspan="3" style="text-indent:2em" | 382.01(25) keV | 6.19(8) ms | IT | 90m1Nb | 1+ | |-id=Niobium-90m5 | style="text-indent:1em" | 90m5Nb | colspan="3" style="text-indent:2em" | 1880.21(20) keV | 471(6) ns | IT | 90Nb | (11−) | |-id=Niobium-91 | rowspan=2|91Nb | rowspan=2 style="text-align:right" | 41 | rowspan=2 style="text-align:right" | 50 | rowspan=2|90.9069903(31) | rowspan=2|680(130) y | EC (99.99%) | rowspan=2|91Zr | rowspan=2|9/2+ | rowspan=2| |- | β+ (0.0138%) |-id=Niobium-91m1 | 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 (96.6%) | 91Nb | rowspan=3|1/2− | rowspan=3| |- | EC (3.4%) | rowspan=2|91Zr |- | β+ (.0028%) |-id=Niobium-91m2 | style="text-indent:1em" | 91m2Nb | colspan="3" style="text-indent:2em" | 2034.42(20) keV | 3.76(12) μs | IT | 91Nb | (17/2−)
| 92Nb | style="text-align:right" | 41 | style="text-align:right" | 51 | 91.9071886(19) | 3.47(24)×107 y | β+ | 92Zr | 7+ | Trace |-id=Niobium-92m1 | style="text-indent:1em" | 92m1Nb | colspan="3" style="text-indent:2em" | 135.5(4) keV | 10.116(13) d | β+ | 92Zr | (2)+ | |-id=Niobium-92m2 | style="text-indent:1em" | 92m2Nb | colspan="3" style="text-indent:2em" | 225.8(4) keV | 5.9(2) μs | IT | 92Nb | (2)− | |-id=Niobium-92m3 | style="text-indent:1em" | 92m3Nb | colspan="3" style="text-indent:2em" | 2203.3(4) keV | 167(4) ns | IT | 92Nb | (11−) | |-id=Niobium-93 | 93Nb | style="text-align:right" | 41 | style="text-align:right" | 52 | 92.9063732(16) | colspan=3 align=center|Stable | 9/2+ | 1.0000 |-id=Niobium-93m1 | style="text-indent:1em" | 93m1Nb | colspan="3" style="text-indent:2em" | 30.760(5) keV | 16.12(12) y | IT | 93Nb | 1/2− | |-id=Niobium-93m2 | style="text-indent:1em" | 93m2Nb | colspan="3" style="text-indent:2em" | 7460(17) keV | 1.5(5) μs | IT | 93Nb | 33/2−# | |-id=Niobium-94 | 94Nb | style="text-align:right" | 41 | style="text-align:right" | 53 | 93.9072790(16) | 2.04(4)×104 y | β− | 94Mo | 6+ | Trace |-id=Niobium-94m | rowspan=2 style="text-indent:1em" | 94mNb | rowspan=2 colspan="3" style="text-indent:2em" | 40.892(12) keV | rowspan=2|6.263(4) min | IT (99.50%) | 94Nb | rowspan=2|3+ | rowspan=2| |- | β− (0.50%) | 94Mo |-id=Niobium-95 | 95Nb | style="text-align:right" | 41 | style="text-align:right" | 54 | 94.90683111(55) | 34.991(6) d | β− | 95Mo | 9/2+ | |-id=Niobium-95m | rowspan=2 style="text-indent:1em" | 95mNb | rowspan=2 colspan="3" style="text-indent:2em" | 235.69(2) keV | rowspan=2|3.61(3) d | IT (94.4%) | 95Nb | rowspan=2|1/2− | rowspan=2| |- | β− (5.6%) | 95Mo |-id=Niobium-96 | 96Nb | style="text-align:right" | 41 | style="text-align:right" | 55 | 95.90810159(16) | 23.35(5) h | β− | 96Mo | 6+ | |-id=Niobium-97 | 97Nb | style="text-align:right" | 41 | style="text-align:right" | 56 | 96.9081016(46) | 72.1(7) min | β− | 97Mo | 9/2+ | |-id=Niobium-97m | style="text-indent:1em" | 97mNb | colspan="3" style="text-indent:2em" | 743.35(3) keV | 58.7(18) s | IT | 97Nb | 1/2− | |-id=Niobium-98 | 98Nb | style="text-align:right" | 41 | style="text-align:right" | 57 | 97.9103326(54) | 2.86(6) s | β− | 98Mo | 1+ | |-id=Niobium-98m | style="text-indent:1em" | 98mNb | colspan="3" style="text-indent:2em" | 84(4) keV | 51.1(4) min | β− | 98Mo | (5)+ | |-id=Niobium-99 | 99Nb | style="text-align:right" | 41 | style="text-align:right" | 58 | 98.911609(13) | 15.0(2) s | β− | 99Mo | 9/2+ | |-id=Niobium-99m | rowspan=2 style="text-indent:1em" | 99mNb | rowspan=2 colspan="3" style="text-indent:2em" | 365.27(8) keV | rowspan=2|2.5(2) min | β− (?%) | 99Mo | rowspan=2|1/2− | rowspan=2| |- | IT (?%) | 99Nb |-id=Niobium-100 | 100Nb | style="text-align:right" | 41 | style="text-align:right" | 59 | 99.9143406(86) | 1.5(2) s | β− | 100Mo | 1+ | |-id=Niobium-100m1 | style="text-indent:1em" | 100m1Nb | colspan="3" style="text-indent:2em" | 313(8) keV | 2.99(11) s | β− | 100Mo | (5+) | |-id=Niobium-100m2 | style="text-indent:1em" | 100m2Nb | colspan="3" style="text-indent:2em" | 347(8) keV | 460(60) ns | IT | 100Nb | (4−,5−) | |-id=Niobium-100m3 | style="text-indent:1em" | 100m3Nb | colspan="3" style="text-indent:2em" | 734(8) keV | 12.43(26) μs | IT | 100Nb | (8−) | |-id=Niobium-101 | 101Nb | style="text-align:right" | 41 | style="text-align:right" | 60 | 100.9153065(40) | 7.1(3) s | β− | 101Mo | 5/2+ | |-id=Niobium-102 | 102Nb | style="text-align:right" | 41 | style="text-align:right" | 61 | 101.9180904(27) | 4.3(4) s | β− | 102Mo | (4+) | |-id=Niobium-102m | style="text-indent:1em" | 102mNb | colspan="3" style="text-indent:2em" | 94(7) keV | 1.31(16) s | β− | 102Mo | (1+) | |-id=Niobium-103 | 103Nb | style="text-align:right" | 41 | style="text-align:right" | 62 | 102.9194534(42) | 1.34(7) s | β− | 103Mo | 5/2+ | |-id=Niobium-104 | rowspan=2|104Nb | rowspan=2 style="text-align:right" | 41 | rowspan=2 style="text-align:right" | 63 | rowspan=2|103.9229077(19) | rowspan=2|0.98(5) s | β− (99.95%) | 104Mo | rowspan=2|(1+) | rowspan=2| |- | β−, n (0.05%) | 103Mo |-id=Niobium-104m | rowspan=2 style="text-indent:1em" | 104mNb | rowspan=2 colspan="3" style="text-indent:2em" | 9.8(26) keV | rowspan=2|4.9(3) s | β− (99.94%) | 104Mo | rowspan=2|(0−,1−) | rowspan=2| |- | β−, n (0.06%) | 103Mo |-id=Niobium-105 | rowspan=2|105Nb | rowspan=2 style="text-align:right" | 41 | rowspan=2 style="text-align:right" | 64 | rowspan=2|104.9249426(43) | rowspan=2|2.91(5) s | β− (98.3%) | 105Mo | rowspan=2|(5/2+) | rowspan=2| |- | β−, n (1.7%) | 104Mo |-id=Niobium-106 | rowspan=2|106Nb | rowspan=2 style="text-align:right" | 41 | rowspan=2 style="text-align:right" | 65 | rowspan=2|105.9289285(15) | rowspan=2|900(20) ms | β− (95.5%) | 106Mo | rowspan=2|1−# | rowspan=2| |- | β−, n (4.5%) | 105Mo |-id=Niobium-106m1 | style="text-indent:1em" | 106m1Nb | colspan="3" style="text-indent:2em" | 100(50)# keV | 1.20(6) s | β− | 106Mo | (4−) | |-id=Niobium-106m2 | style="text-indent:1em" | 106m2Nb | colspan="3" style="text-indent:2em" | 204.8(5) keV | 820(38) ns | IT | 106Nb | (3+) | |-id=Niobium-107 | rowspan=2|107Nb | rowspan=2 style="text-align:right" | 41 | rowspan=2 style="text-align:right" | 66 | rowspan=2|106.9315897(86) | rowspan=2|286(8) ms | β− (92.6%) | 107Mo | rowspan=2|(5/2+) | rowspan=2| |- | β−, n (7.4%) | 106Mo |-id=Niobium-108 | rowspan=2|108Nb | rowspan=2 style="text-align:right" | 41 | rowspan=2 style="text-align:right" | 67 | rowspan=2|107.9360756(88) | rowspan=2|201(4) ms | β− (93.7%) | 108Mo | rowspan=2|(2+) | rowspan=2| |- | β−, n (6.3%) | 107Mo |-id=Niobium-108m | style="text-indent:1em" | 108mNb | colspan="3" style="text-indent:2em" | 166.6(5) keV | 109(2) ns | IT | 109Nb | 6−# | |-id=Niobium-109 | rowspan=2|109Nb | rowspan=2 style="text-align:right" | 41 | rowspan=2 style="text-align:right" | 68 | rowspan=2|108.93914(46) | rowspan=2|106.9(49) ms | β− (69%) | 109Mo | rowspan=2|3/2−# | rowspan=2| |- | β−, n (31%) | 108Mo |-id=Niobium-109m | style="text-indent:1em" | 109mNb | colspan="3" style="text-indent:2em" | 312.5(4) keV | 115(8) ns | IT | 109Nb | 7/2+# | |-id=Niobium-110 | rowspan=2|110Nb | rowspan=2 style="text-align:right" | 41 | rowspan=2 style="text-align:right" | 69 | rowspan=2|109.94384(90) | rowspan=2|75(1) ms | β− (60%) | 110Mo | rowspan=2|5+# | rowspan=2| |- | β−, n (40%) | 109Mo |-id=Niobium-110m | rowspan=2 style="text-indent:1em" | 110mNb | rowspan=2 colspan="3" style="text-indent:2em" | 100(50)# keV | rowspan=2|94(9) ms | β− (60%) | 104Mo | rowspan=2|2+# | rowspan=2| |- | β−, n (40%) | 103Mo |-id=Niobium-111 | 111Nb | style="text-align:right" | 41 | style="text-align:right" | 70 | 110.94744(32)# | 54(2) ms | β− | 111Mo | 3/2−# | |-id=Niobium-112 | 112Nb | style="text-align:right" | 41 | style="text-align:right" | 71 | 111.95269(32)#