Naturally occurring zirconium (40Zr) is composed of four stable isotopes (one, 94Zr, may in the future be found radioactive), and one very long-lived radioisotope (96Zr), a primordial nuclide that decays via double beta decay with an observed partial half-life of 2.34 × 1019 years; it can also undergo single beta decay, with a partial half-life of [2.27 (stat) ± 0.27 (syst)] × 1020 years. The second most stable radioisotope is 93Zr, which has a half-life of 1.61 million years. Thirty other radioisotopes have been observed from 77Zr to 114Zr; all have half-lives less than a day except for 95Zr (64.032 days), 88Zr (83.4 days), and 89Zr (78.36 hours). The most stable of the isomeric states is just 4.16 minutes for 89mZr.
Radioactive isotopes above the theoretically stable mass numbers 90–92 decay by electron emission resulting in niobium isotopes, whereas those below by positron emission or electron capture, resulting in yttrium isotopes.
List of isotopes
|-id=Zirconium-77 | 77Zr | style="text-align:right" | 40 | style="text-align:right" | 37 | 76.96608(43)# | style="text-align:center" | 2017 | 100# μs
| 3/2−#
|-id=Zirconium-78 | 78Zr | style="text-align:right" | 40 | style="text-align:right" | 38 | 77.95615(43)# | style="text-align:center" | 2001 | 50# ms[>200 ns]
| 0+
|-id=Zirconium-79 | 79Zr | style="text-align:right" | 40 | style="text-align:right" | 39 | 78.94979(32)# | style="text-align:center" | 1999 | 56(30) ms | β+ | 79Y | 5/2+#
|-id=Zirconium-80 | 80Zr | style="text-align:right" | 40 | style="text-align:right" | 40 | 79.940818(86) | style="text-align:center" | 1987 | 4.6(6) s | β+ | 80Y | 0+
|-id=Zirconium-81 | rowspan=2|81Zr | rowspan=2 style="text-align:right" | 40 | rowspan=2 style="text-align:right" | 41 | rowspan=2|80.938211(11) | rowspan=2 style="text-align:center" | 1997 | rowspan=2|5.5(4) s | β+ (99.88%) | 81Y | rowspan=2|(3/2−) | rowspan=2| | rowspan=2| |- | β+, p (0.12%) | 80Sr |-id=Zirconium-82 | 82Zr | style="text-align:right" | 40 | style="text-align:right" | 42 | 81.9317075(17) | style="text-align:center" | 1982 | 32(5) s | β+ | 82Y | 0+
|-id=Zirconium-83 | rowspan=2|83Zr | rowspan=2 style="text-align:right" | 40 | rowspan=2 style="text-align:right" | 43 | rowspan=2|82.92923591(70) | rowspan=2 style="text-align:center" | 1974 | rowspan=2|42(2) s | β+ | 83Y | rowspan=2|1/2−# | rowspan=2| | rowspan=2| |- | β+, p (?%) | 82Sr |-id=Zirconium-83m1 | style="text-indent:1em" | 83m1Zr | colspan="3" style="text-indent:2em" | 52.72(5) keV | style="text-align:center" | 1988 | 0.53(12) μs | IT | 83Zr | (5/2−)
|-id=Zirconium-83m2 | style="text-indent:1em" | 83m2Zr | colspan="3" style="text-indent:2em" | 77.04(7) keV | style="text-align:center" | 1988 | 1.8(1) μs | IT | 83Zr | (7/2+)
|-id=Zirconium-84 | 84Zr | style="text-align:right" | 40 | style="text-align:right" | 44 | 83.9233257(59) | style="text-align:center" | 1977 | 25.8(5) min | β+ | 84Y | 0+
|-id=Zirconium-85 | 85Zr | style="text-align:right" | 40 | style="text-align:right" | 45 | 84.9214432(69) | style="text-align:center" | 1963 | 7.86(4) min | β+ | 85Y | (7/2+)
|-id=Zirconium-85m | rowspan=2 style="text-indent:1em" | 85mZr | rowspan=2 colspan="3" style="text-indent:2em" | 292.2(3) keV | rowspan=2 style="text-align:center" | 1976 | rowspan=2|10.9(3) s | IT (?%) | 85Zr | rowspan=2|1/2−# | rowspan=2| | rowspan=2| |- | β+ (?%) | 85Y |-id=Zirconium-86 | 86Zr | style="text-align:right" | 40 | style="text-align:right" | 46 | 85.9162968(38) | style="text-align:center" | 1951 | 16.5(1) h | β+ | 86Y | 0+
|-id=Zirconium-87 | 87Zr | style="text-align:right" | 40 | style="text-align:right" | 47 | 86.9148173(45) | style="text-align:center" | 1949 | 1.68(1) h | β+ | 87Y | 9/2+
|-id=Zirconium-87m | style="text-indent:1em" | 87mZr | colspan="3" style="text-indent:2em" | 335.84(19) keV | style="text-align:center" | 1972 | 14.0(2) s | IT | 87Zr | 1/2−
| 88ZrSecond most powerful known neutron absorber | style="text-align:right" | 40 | style="text-align:right" | 48 | 87.9102207(58) | style="text-align:center" | 1951 | 83.4(3) d | EC | 88Y | 0+
|-id=Zirconium-88m | style="text-indent:1em" | 88mZr | colspan="3" style="text-indent:2em" | 2887.79(6) keV | style="text-align:center" | 1971 | 1.320(25) μs | IT | 88Zr | 8+
| 89Zr | style="text-align:right" | 40 | style="text-align:right" | 49 | 88.9088798(30) | style="text-align:center" | 1938 | 78.360(23) h | β+ | 89Y | 9/2+
|-id=Zirconium-89m | rowspan=2 style="text-indent:1em" | 89mZr | rowspan=2 colspan="3" style="text-indent:2em" | 587.82(10) keV | rowspan=2 style="text-align:center" | 1940 | rowspan=2|4.161(10) min | IT (93.77%) | 89Zr | rowspan=2|1/2− | rowspan=2| | rowspan=2| |- | β+ (6.23%) | 89Y |-id=Zirconium-90 | 90ZrFission product | style="text-align:right" | 40 | style="text-align:right" | 50 | 89.90469876(13) | style="text-align:center" | 1924 | colspan=3 align=center|Stable | 0+ | 0.5145(4) | |-id=Zirconium-90m1 | style="text-indent:1em" | 90m1Zr | colspan="3" style="text-indent:2em" | 2319.000(9) keV | style="text-align:center" | 1963 | 809.2(20) ms | IT | 90Zr | 5-
|-id=Zirconium-90m2 | style="text-indent:1em" | 90m2Zr | colspan="3" style="text-indent:2em" | 3589.418(15) keV | style="text-align:center" | 1959 | 131(4) ns | IT | 90Zr | 8+
|-id=Zirconium-91 | 91Zr | style="text-align:right" | 40 | style="text-align:right" | 51 | 90.90564021(10) | style="text-align:center" | 1934 | colspan=3 align=center|Stable | 5/2+ | 0.1122(5) | |-id=Zirconium-91m | style="text-indent:1em" | 91mZr | colspan="3" style="text-indent:2em" | 3167.3(4) keV | style="text-align:center" | 1975 | 4.35(14) μs | IT | 91Zr | (21/2+)
|-id=Zirconium-92 | 92Zr | style="text-align:right" | 40 | style="text-align:right" | 52 | 91.90503534(10) | style="text-align:center" | 1924 | colspan=3 align=center|Stable | 0+ | 0.1715(3)
| rowspan=2 | 93ZrLong-lived fission product | rowspan=2 style="text-align:right" | 40 | rowspan=2 style="text-align:right" | 53 | rowspan=2 | 92.90647066(49) | rowspan=2 style="text-align:center" | 1950 | rowspan=2 | 1.61(5)×106 y | β− (73%) | 93m1Nb | rowspan=2 | 5/2+ | rowspan=2 | | rowspan=2 | |- | β− (27%) | 93Nb |-id=Zirconium-94 | 94Zr | style="text-align:right" | 40 | style="text-align:right" | 54 | 93.90631252(18) | style="text-align:center" | 1924 | colspan=3 align=center|Observationally stableBelieved to decay by β−β− to 94Mo with a half-life over 1.1×1017 years | 0+ | 0.1738(4) | |-id=Zirconium-95 | 95Zr | style="text-align:right" | 40 | style="text-align:right" | 55 | 94.90804028(93) | style="text-align:center" | 1946 | 64.032(6) d | β− | 95Nb | 5/2+
|-id=Zirconium-96 | rowspan=2 | 96ZrPrimordial radionuclide | rowspan=2 style="text-align:right" | 40 | rowspan=2 style="text-align:right" | 56 | rowspan=2 | 95.90827762(12) | rowspan=2 style="text-align:center" | 1934 | rowspan=2 | 2.1(2)×1019 y | β−β− (91%) | 96Mo | rowspan=2 |0+ | rowspan=2 |0.0280(2) | rowspan=2 | |- | β− (9%) | 96Nb |-id=Zirconium-97 | 97Zr | style="text-align:right" | 40 | style="text-align:right" | 57 | 96.91096380(13) | style="text-align:center" | 1951 | 16.749(8) h | β− | 97mNb | 1/2+
|-id=Zirconium-97m | style="text-indent:1em" | 97mZr | colspan="3" style="text-indent:2em" | 1264.35(16) keV | style="text-align:center" | 1985 | 104.8(17) ns | IT | 97Zr | 7/2+
|-id=Zirconium-98 | 98Zr | style="text-align:right" | 40 | style="text-align:right" | 58 | 97.9127404(91) | style="text-align:center" | 1967 | 30.7(4) s | β− | 98Nb | 0+
|-id=Zirconium-98m | style="text-indent:1em" | 98mZr | colspan="3" style="text-indent:2em" | 6601.9(11) keV | style="text-align:center" | 2006 | 1.9(2) μs | IT | 98Zr | (17−)
|-id=Zirconium-99 | 99Zr | style="text-align:right" | 40 | style="text-align:right" | 59 | 98.916675(11) | style="text-align:center" | 1970 | 2.1(1) s | β− | 99mNb | 1/2+
|-id=Zirconium-99m | style="text-indent:1em" | 99mZr | colspan="3" style="text-indent:2em" | 251.96(9) keV | style="text-align:center" | 1970 | 336(5) ns | IT | 99Zr | 7/2+
|-id=Zirconium-100 | 100Zr | style="text-align:right" | 40 | style="text-align:right" | 60 | 99.9180105(87) | style="text-align:center" | 1970 | 7.1(4) s | β− | 100Nb | 0+
|-id=Zirconium-101 | 101Zr | style="text-align:right" | 40 | style="text-align:right" | 61 | 100.9214585(89) | style="text-align:center" | 1970 | 2.29(8) s | β− | 101Nb | 3/2+
|-id=Zirconium-102 | 102Zr | style="text-align:right" | 40 | style="text-align:right" | 62 | 101.9231542(94) | style="text-align:center" | 1970 | 2.01(8) s | β− | 102Nb | 0+
|-id=Zirconium-103 | rowspan=2|103Zr | rowspan=2 style="text-align:right" | 40 | rowspan=2 style="text-align:right" | 63 | rowspan=2|102.9272041(99) | rowspan=2 style="text-align:center" | 1987 | rowspan=2|1.38(7) s | β− (>99%) | 103Nb | rowspan=2|(5/2−) | rowspan=2| | rowspan=2| |- | β−, n (<1%) | 102Nb |-id=Zirconium-104 | rowspan=2|104Zr | rowspan=2 style="text-align:right" | 40 | rowspan=2 style="text-align:right" | 64 | rowspan=2|103.929449(10) | rowspan=2 style="text-align:center" | 1990 | rowspan=2|920(28) ms | β− (>99%) | 104Nb | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β−, n (<1%) | 103Nb |-id=Zirconium-105 | rowspan=2|105Zr | rowspan=2 style="text-align:right" | 40 | rowspan=2 style="text-align:right" | 65 | rowspan=2|104.934022(13) | rowspan=2 style="text-align:center" | 1992 | rowspan=2|670(28) ms | β− (>98%) | 105Nb | rowspan=2|1/2+# | rowspan=2| | rowspan=2| |- | β−, n (<2%) | 104Nb |-id=Zirconium-106 | rowspan=2|106Zr | rowspan=2 style="text-align:right" | 40 | rowspan=2 style="text-align:right" | 66 | rowspan=2|105.93693(22)# | rowspan=2 style="text-align:center" | 1994 | rowspan=2|179(6) ms | β− (>98%) | 106Nb | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β−, n (<2%) | 105Nb |-id=Zirconium-107 | rowspan=2|107Zr | rowspan=2 style="text-align:right" | 40 | rowspan=2 style="text-align:right" | 67 | rowspan=2|106.94201(32)# | rowspan=2 style="text-align:center" | 1994 | rowspan=2|145.7(24) ms | β− (>77%) | 107Nb | rowspan=2|5/2+# | rowspan=2| | rowspan=2| |- | β−, n (<23%) | 106Nb |-id=Zirconium-108 | 108Zr | style="text-align:right" | 40 | style="text-align:right" | 68 | 107.94530(43)# | style="text-align:center" | 1997 | 78.5(20) ms | β− | 108Nb | 0+
|-id=Zirconium-108m | style="text-indent:1em" | 108mZr | colspan="3" style="text-indent:2em" | 2074.5(8) keV | style="text-align:center" | 2011 | 540(30) ns | IT | 108Zr | (6+)
|-id=Zirconium-109 | 109Zr | style="text-align:right" | 40 | style="text-align:right" | 69 | 108.95091(54)# | style="text-align:center" | 1997 | 56(3) ms | β− | 109Nb | 5/2+#
|-id=Zirconium-110 | 110Zr | style="text-align:right" | 40 | style="text-align:right" | 70 | 109.95468(54)# | style="text-align:center" | 1997 | 37.5(20) ms | β− | 110Nb | 0+
|-id=Zirconium-111 | 111Zr | style="text-align:right" | 40 | style="text-align:right" | 71 | 110.96084(64)# | style="text-align:center" | 2010 | 24.0(5) ms | β− | 111Nb | 5/2+#
|-id=Zirconium-111m | style="text-indent:1em" | 111mZr | colspan="3" style="text-indent:2em" | 265 keV | style="text-align:center" | 2022 | 100(70) ns | IT | 111Zr
|-id=Zirconium-112 | 112Zr | style="text-align:right" | 40 | style="text-align:right" | 72 | 111.96520(75)# | style="text-align:center" | 2010 | 43(21) ms | β− | 112Nb | 0+
|-id=Zirconium-113 | 113Zr | style="text-align:right" | 40 | style="text-align:right" | 73 | 112.97172(32)# | style="text-align:center" | 2018 | 15# ms[>550 ns]
| 3/2+
|-id=Zirconium-114 | 114Zr | style="text-align:right" | 40 | style="text-align:right" | 74 | | style="text-align:center" | 2021
| 0+
Zirconium-88 88Zr is a radioisotope of zirconium with a half-life of 83.4 days. In January 2019, this isotope was discovered to have a thermal neutron capture cross section of approximately 861,000 barns; this is several orders of magnitude greater than predicted, and greater than that of any other nuclide except xenon-135.
Zirconium-89