Isotopes of molybdenum#Applications

Molybdenum (₄₂Mo) has 39 known isotopes, ranging in atomic mass from 81 to 119, as well as four metastable nuclear isomers. Seven isotopes occur naturally, with atomic masses of 92, 94, 95, 96, 97, 98, and 100. All unstable isotopes of molybdenum decay into isotopes of zirconium, niobium, technetium, and ruthenium.{{CRC87}}

Molybdenum-100, with a half-life of 7.07{{e|18}} years, is the only naturally occurring radioisotope. It undergoes double beta decay into ruthenium-100. Molybdenum-98 is the most common isotope, comprising 24.14% of all molybdenum on Earth.

List of isotopes

{{Isotopes table

|symbol=Mb

|refs=NUBASE2020, AME2020 II

|notes=m, unc(), mass#, spin(), hl-nst, spin#, daughter-st, n, p, IT, EC

}}

|-id=Molybdenum-81

| rowspan=2|⁸¹Mo

| rowspan=2 style="text-align:right" | 42

| rowspan=2 style="text-align:right" | 39

| rowspan=2|80.96623(54)#

| rowspan=2|1# ms
[>400 ns]

| β⁺?

| ⁸¹Nb

| rowspan=2|5/2+#

| rowspan=2|

| β⁺, p?

| ⁸⁰Zr

|-id=Molybdenum-82

| rowspan=2|⁸²Mo

| rowspan=2 style="text-align:right" | 42

| rowspan=2 style="text-align:right" | 40

| rowspan=2|81.95666(43)#

| rowspan=2|30# ms
[>400 ns]

| β⁺?

| ⁸²Nb

| rowspan=2|0+

| rowspan=2|

| β⁺, p?

| ⁸¹Zr

|-id=Molybdenum-83

| rowspan=2|⁸³Mo

| rowspan=2 style="text-align:right" | 42

| rowspan=2 style="text-align:right" | 41

| rowspan=2|82.95025(43)#

| rowspan=2|23(19) ms

| β⁺

| ⁸³Nb

| rowspan=2|3/2−#

| rowspan=2|

| β⁺, p?

| ⁸²Zr

|-id=Molybdenum-84

| rowspan=2|⁸⁴Mo

| rowspan=2 style="text-align:right" | 42

| rowspan=2|83.94185(32)#

| rowspan=2|2.3(3) s

| β⁺

| ⁸⁴Nb

| rowspan=2|0+

| rowspan=2|

| β⁺, p?

| ⁸³Zr

|-id=Molybdenum-85

| rowspan=2|⁸⁵Mo

| rowspan=2 style="text-align:right" | 42

| rowspan=2 style="text-align:right" | 43

| rowspan=2|84.938261(17)

| rowspan=2|3.2(2) s

| β⁺ (99.86%)

| ⁸⁵Nb

| rowspan=2|(1/2+)

| rowspan=2|

| β⁺, p (0.14%)

| ⁸⁴Zr

|-id=Molybdenum-86

| ⁸⁶Mo

| style="text-align:right" | 42

| style="text-align:right" | 44

| 85.931174(3)

| 19.1(3) s

| β⁺

| ⁸⁶Nb

| 0+

|-id=Molybdenum-87

| rowspan=2|⁸⁷Mo

| rowspan=2 style="text-align:right" | 42

| rowspan=2 style="text-align:right" | 45

| rowspan=2|86.928196(3)

| rowspan=2|14.1(3) s

| β⁺ (85%)

| ⁸⁷Nb

| rowspan=2|7/2+#

| rowspan=2|

| β⁺, p (15%)

| ⁸⁶Zr

|-id=Molybdenum-88

| ⁸⁸Mo

| style="text-align:right" | 42

| style="text-align:right" | 46

| 87.921968(4)

| 8.0(2) min

| β⁺

| ⁸⁸Nb

| 0+

|-id=Molybdenum-89

| ⁸⁹Mo

| style="text-align:right" | 42

| style="text-align:right" | 47

| 88.919468(4)

| 2.11(10) min

| β⁺

| ⁸⁹Nb

| (9/2+)

|-id=Molybdenum-89m

| style="text-indent:1em" | ^89mMo

| colspan="3" style="text-indent:2em" | 387.5(2) keV

| 190(15) ms

| IT

| ⁸⁹Mo

| (1/2−)

|-id=Molybdenum-90

| ⁹⁰Mo

| style="text-align:right" | 42

| style="text-align:right" | 48

| 89.913931(4)

| 5.56(9) h

| β⁺

| ⁹⁰Nb

| 0+

|-id=Molybdenum-90m

| style="text-indent:1em" | ^90mMo

| colspan="3" style="text-indent:2em" | 2874.73(15) keV

| 1.14(5) μs

| IT

| ⁹⁰Mo

| 8+

|-id=Molybdenum-91

| ⁹¹Mo

| style="text-align:right" | 42

| style="text-align:right" | 49

| 90.911745(7)

| 15.49(1) min

| β⁺

| ⁹¹Nb

| 9/2+

|-id=Molybdenum-91m

| rowspan=2 style="text-indent:1em" | ^91mMo

| rowspan=2 colspan="3" style="text-indent:2em" | 653.01(9) keV

| rowspan=2|64.6(6) s

| IT (50.0%)

| ⁹¹Mo

| rowspan=2|1/2−

| rowspan=2|

| β⁺ (50.0%)

| ⁹¹Nb

|-id=Molybdenum-92

| ⁹²Mo

| style="text-align:right" | 42

| style="text-align:right" | 50

| 91.90680715(17)

| colspan=3 align=center|Observationally StableBelieved to decay by β⁺β⁺ to ⁹²Zr with a half-life over 1.9×10²⁰ y

| 0+

| 0.14649(106)

|-id=Molybdenum-92m

| style="text-indent:1em" | ^92mMo

| colspan="3" style="text-indent:2em" | 2760.52(14) keV

| 190(3) ns

| IT

| ⁹²Mo

| 8+

|-id=Molybdenum-93

| rowspan=2|⁹³Mo

| rowspan=2 style="text-align:right" | 42

| rowspan=2 style="text-align:right" | 51

| rowspan=2|92.90680877(19)

| rowspan=2|4839(63) y

| EC (95.7%)

| ^93mNb

| rowspan=2|5/2+

| rowspan=2|

| EC (4.3%)

| ⁹³Nb

|-id=Molybdenum-93m1

| rowspan=2 style="text-indent:1em" | ^93m1Mo

| rowspan=2 colspan="3" style="text-indent:2em" | 2424.95(4) keV

| rowspan=2|6.85(7) h

| IT (99.88%)

| ⁹³Mo

| rowspan=2|21/2+

| rowspan=2|

| β⁺ (0.12%)

| ⁹³Nb

|-id=Molybdenum-93m2

| style="text-indent:1em" | ^93m2Mo

| colspan="3" style="text-indent:2em" | 9695(17) keV

| 1.8(10) μs

| IT

| ⁹³Mo

| (39/2−)

|-id=Molybdenum-94

| ⁹⁴Mo

| style="text-align:right" | 42

| style="text-align:right" | 52

| 93.90508359(15)

| colspan=3 align=center|Stable

| 0+

| 0.09187(33)

|-id=Molybdenum-95

| ⁹⁵MoFission product

| style="text-align:right" | 42

| style="text-align:right" | 53

| 94.90583744(13)

| colspan=3 align=center|Stable

| 5/2+

| 0.15873(30)

|-id=Molybdenum-96

| ⁹⁶Mo

| style="text-align:right" | 42

| style="text-align:right" | 54

| 95.90467477(13)

| colspan=3 align=center|Stable

| 0+

| 0.16673(8)

|-id=Molybdenum-97

| ⁹⁷Mo

| style="text-align:right" | 42

| style="text-align:right" | 55

| 96.90601690(18)

| colspan=3 align=center|Stable

| 5/2+

| 0.09582(15)

|-id=Molybdenum-98

| ⁹⁸Mo

| style="text-align:right" | 42

| style="text-align:right" | 56

| 97.90540361(19)

| colspan=3 align=center|Observationally StableBelieved to decay by β⁻β⁻ to ⁹⁸Ru with a half-life of over 1×10¹⁴ years

| 0+

| 0.24292(80)

| ⁹⁹MoUsed to produce the medically useful radioisotope technetium-99m

| style="text-align:right" | 42

| style="text-align:right" | 57

| 98.90770730(25)

| 65.932(5) h

| β⁻

| ^99mTc

| 1/2+

|-id=Molybdenum-99m1

| style="text-indent:1em" | ^99m1Mo

| colspan="3" style="text-indent:2em" | 97.785(3) keV

| 15.5(2) μs

| IT

| ⁹⁹Mo

| 5/2+

|-id=Molybdenum-99m2

| style="text-indent:1em" | ^99m2Mo

| colspan="3" style="text-indent:2em" | 684.10(19) keV

| 760(60) ns

| IT

| ⁹⁹Mo

| 11/2−

|-id=Molybdenum-100

| ¹⁰⁰MoPrimordial radionuclide

| style="text-align:right" | 42

| style="text-align:right" | 58

| 99.9074680(3)

| 7.07(14)×10¹⁸ y

| β⁻β⁻

| ¹⁰⁰Ru

| 0+

| 0.09744(65)

|-id=Molybdenum-101

| ¹⁰¹Mo

| style="text-align:right" | 42

| style="text-align:right" | 59

| 100.9103376(3)

| 14.61(3) min

| β⁻

| ¹⁰¹Tc

| 1/2+

|-id=Molybdenum-101m1

| style="text-indent:1em" | ^101m1Mo

| colspan="3" style="text-indent:2em" | 13.497(9) keV

| 226(7) ns

| IT

| ¹⁰¹Mo

| 3/2+

|-id=Molybdenum-101m2

| style="text-indent:1em" | ^101m2Mo

| colspan="3" style="text-indent:2em" | 57.015(11) keV

| 133(70) ns

| IT

| ¹⁰¹Mo

| 5/2+

|-id=Molybdenum-102

| ¹⁰²Mo

| style="text-align:right" | 42

| style="text-align:right" | 60

| 101.910294(9)

| 11.3(2) min

| β⁻

| ¹⁰²Tc

| 0+

|-id=Molybdenum-103

| ¹⁰³Mo

| style="text-align:right" | 42

| style="text-align:right" | 61

| 102.913092(10)

| 67.5(15) s

| β⁻

| ¹⁰³Tc

| 3/2+

|-id=Molybdenum-104

| ¹⁰⁴Mo

| style="text-align:right" | 42

| style="text-align:right" | 62

| 103.913747(10)

| 60(2) s

| β⁻

| ¹⁰⁴Tc

| 0+

|-id=Molybdenum-105

| ¹⁰⁵Mo

| style="text-align:right" | 42

| style="text-align:right" | 63

| 104.9169798(23){{cite journal |last1=Jaries |first1=A. |last2=Stryjczyk |first2=M. |last3=Kankainen |first3=A. |last4=Ayoubi |first4=L. Al |last5=Beliuskina |first5=O. |last6=Canete |first6=L. |last7=de Groote |first7=R. P. |last8=Delafosse |first8=C. |last9=Delahaye |first9=P. |last10=Eronen |first10=T. |last11=Flayol |first11=M. |last12=Ge |first12=Z. |last13=Geldhof |first13=S. |last14=Gins |first14=W. |last15=Hukkanen |first15=M. |last16=Imgram |first16=P. |last17=Kahl |first17=D. |last18=Kostensalo |first18=J. |last19=Kujanpää |first19=S. |last20=Kumar |first20=D. |last21=Moore |first21=I. D. |last22=Mougeot |first22=M. |last23=Nesterenko |first23=D. A. |last24=Nikas |first24=S. |last25=Patel |first25=D. |last26=Penttilä |first26=H. |last27=Pitman-Weymouth |first27=D. |last28=Pohjalainen |first28=I. |last29=Raggio |first29=A. |last30=Ramalho |first30=M. |last31=Reponen |first31=M. |last32=Rinta-Antila |first32=S. |last33=de Roubin |first33=A. |last34=Ruotsalainen |first34=J. |last35=Srivastava |first35=P. C. |last36=Suhonen |first36=J. |last37=Vilen |first37=M. |last38=Virtanen |first38=V. |last39=Zadvornaya |first39=A. |title=Physical Review C - Accepted Paper: Isomeric states of fission fragments explored via Penning trap mass spectrometry at IGISOL |journal=journals.aps.org |url=https://journals.aps.org/prc/accepted/fe077P3cDac1f601a8c16c34b19fb124fc3509f19 |arxiv=2403.04710}}

| 36.3(8) s

| β⁻

| ¹⁰⁵Tc

| (5/2−)

|-id=Molybdenum-106

| ¹⁰⁶Mo

| style="text-align:right" | 42

| style="text-align:right" | 64

| 105.9182732(98)

| 8.73(12) s

| β⁻

| ¹⁰⁶Tc

| 0+

|-id=Molybdenum-107

| ¹⁰⁷Mo

| style="text-align:right" | 42

| style="text-align:right" | 65

| 106.9221198(99)

| 3.5(5) s

| β⁻

| ¹⁰⁷Tc

| (1/2+)

|-id=Molybdenum-107m

| style="text-indent:1em" | ^107mMo

| colspan="3" style="text-indent:2em" | 65.4(2) keV

| 445(21) ns

| IT

| ¹⁰⁷Mo

| (5/2+)

|-id=Molybdenum-108

| rowspan=2|¹⁰⁸Mo

| rowspan=2 style="text-align:right" | 42

| rowspan=2 style="text-align:right" | 66

| rowspan=2|107.9240475(99)

| rowspan=2|1.105(10) s

| β⁻ (>99.5%)

| ¹⁰⁸Tc

| rowspan=2|0+

| rowspan=2|

| β⁻, n (<0.5%)

| ¹⁰⁷Tc

|-id=Molybdenum-109

| rowspan=2|¹⁰⁹Mo

| rowspan=2 style="text-align:right" | 42

| rowspan=2 style="text-align:right" | 67

| rowspan=2|108.928438(12)

| rowspan=2|700(14) ms

| β⁻ (98.7%)

| ¹⁰⁹Tc

| rowspan=2|(1/2+)

| rowspan=2|

| β⁻, n (1.3%)

| ¹⁰⁸Tc

|-id=Molybdenum-109m

| style="text-indent:1em" | ^109mMo

| colspan="3" style="text-indent:2em" | 69.7(5) keV

| 210(60) ns

| IT

| ¹⁰⁹Mo

| 5/2+#

|-id=Molybdenum-110

| rowspan=2|¹¹⁰Mo

| rowspan=2 style="text-align:right" | 42

| rowspan=2 style="text-align:right" | 68

| rowspan=2|109.930718(26)

| rowspan=2|292(7) ms

| β⁻ (98.0%)

| ¹¹⁰Tc

| rowspan=2|0+

| rowspan=2|

| β⁻, n (2.0%)

| ¹⁰⁹Tc

|-id=Molybdenum-111

| rowspan=2|¹¹¹Mo

| rowspan=2 style="text-align:right" | 42

| rowspan=2 style="text-align:right" | 69

| rowspan=2|110.935652(14)

| rowspan=2|193.6(44) ms

| β⁻ (>88%)

| ¹¹¹Tc

| rowspan=2|1/2+#

| rowspan=2|

| β⁻, n (<12%)

| ¹¹⁰Tc

|-id=Molybdenum-111m

| rowspan=2 style="text-indent:1em" | ^111mMo

| rowspan=2 colspan="3" style="text-indent:2em" | 100(50)# keV

| rowspan=2|~200 ms

| β⁻

| ¹¹¹Tc

| rowspan=2|7/2−#

| rowspan=2|

| β⁻, n?

| ¹¹⁰Tc

|-id=Molybdenum-112

| rowspan=2|¹¹²Mo

| rowspan=2 style="text-align:right" | 42

| rowspan=2 style="text-align:right" | 70

| rowspan=2|111.93829(22)#

| rowspan=2|125(5) ms

| β⁻

| ¹¹²Tc

| rowspan=2|0+

| rowspan=2|

| β⁻, n?

| ¹¹¹Tc

|-id=Molybdenum-113

| rowspan=2|¹¹³Mo

| rowspan=2 style="text-align:right" | 42

| rowspan=2 style="text-align:right" | 71

| rowspan=2|112.94348(32)#

| rowspan=2|80(2) ms

| β⁻

| ¹¹³Tc

| rowspan=2|5/2+#

| rowspan=2|

| β⁻, n?

| ¹¹²Tc

|-id=Molybdenum-114

| rowspan=2|¹¹⁴Mo

| rowspan=2 style="text-align:right" | 42

| rowspan=2 style="text-align:right" | 72

| rowspan=2|113.94667(32)#

| rowspan=2|58(2) ms

| β⁻

| ¹¹⁴Tc

| rowspan=2|0+

| rowspan=2|

| β⁻, n?

| ¹¹³Tc

|-id=Molybdenum-115

| rowspan=3|¹¹⁵Mo

| rowspan=3 style="text-align:right" | 42

| rowspan=3 style="text-align:right" | 73

| rowspan=3|114.95217(43)#

| rowspan=3|45.5(20) ms

| β⁻

| ¹¹⁵Tc

| rowspan=3|3/2+#

| rowspan=3|

| β⁻, n?

| ¹¹⁴Tc

| β⁻, 2n?

| ¹¹³Tc

|-id=Molybdenum-116

| rowspan=3|¹¹⁶Mo

| rowspan=3 style="text-align:right" | 42

| rowspan=3 style="text-align:right" | 74

| rowspan=3|115.95576(54)#

| rowspan=3|32(4) ms

| β⁻

| ¹¹⁶Tc

| rowspan=3|0+

| rowspan=3|

| β⁻, n?

| ¹¹⁵Tc

| β⁻, 2n?

| ¹¹⁴Tc

|-id=Molybdenum-117

| rowspan=3|¹¹⁷Mo

| rowspan=3 style="text-align:right" | 42

| rowspan=3 style="text-align:right" | 75

| rowspan=3|116.96169(54)#

| rowspan=3|22(5) ms

| β⁻

| ¹¹⁷Tc

| rowspan=3|3/2+#

| rowspan=3|

| β⁻, n?

| ¹¹⁶Tc

| β⁻, 2n?

| ¹¹⁵Tc

|-id=Molybdenum-118

| rowspan=3|¹¹⁸Mo

| rowspan=3 style="text-align:right" | 42

| rowspan=3 style="text-align:right" | 76

| rowspan=3|117.96525(54)#

| rowspan=3|21(6) ms

| β⁻

| ¹¹⁸Tc

| rowspan=3|0+

| rowspan=3|

| β⁻, n?

| ¹¹⁷Tc

| β⁻, 2n?

| ¹¹⁶Tc

|-id=Molybdenum-119

|rowspan=3| ¹¹⁹Mo

|rowspan=3 style="text-align:right" | 42

|rowspan=3 style="text-align:right" | 77

|rowspan=3|118.97147(32)#

|rowspan=3| 12# ms
[>550 ns]

| β⁻?

| ¹¹⁹Tc

|rowspan=3|3/2+#

|rowspan=3|

| β⁻, n?

| ¹¹⁸Tc

| β⁻, 2n?

| ¹¹⁷Tc

Molybdenum-99

Molybdenum-99 is produced commercially by intense neutron-bombardment of a highly purified uranium-235 target, followed rapidly by extraction.{{cite journal|title=Feasibility of Eliminating the Use of Highly Enriched Uranium in the Production of Medical Radioisotopes|author=Frank N. Von Hippel |author2=Laura H. Kahn |journal=Science & Global Security |volume=14 |issue= 2 & 3 |date=December 2006 |pages=151–162 |doi=10.1080/08929880600993071 |bibcode=2006S&GS...14..151V|s2cid=122507063 }} It is used as a parent radioisotope in technetium-99m generators to produce the even shorter-lived daughter isotope technetium-99m, which is used in approximately 40 million medical procedures annually. A common misunderstanding or misnomer is that ⁹⁹Mo is used in these diagnostic medical scans, when actually it has no role in the imaging agent or the scan itself. In fact, ⁹⁹Mo co-eluted with the ^99mTc (also known as breakthrough) is considered a contaminant and is minimised to adhere to the appropriate USP (or equivalent) regulations and standards. The IAEA recommends that ⁹⁹Mo concentrations exceeding more than 0.15 μCi/mCi ^99mTc or 0.015% should not be administered for usage in humans.{{Cite report|url=https://inis.iaea.org/collection/NCLCollectionStore/_Public/44/122/44122606.pdf|title=Minimizing Molybdenum-99 Contamination In Technetium-99m Pertechnetate From The Elution Of ⁹⁹Mo/^99mTc Generator|vauthors=Ibrahim I, Zulkifli H, Bohari Y, Zakaria I, ((Wan Hamirul BWK)) }} Typically, quantification of ⁹⁹Mo breakthrough is performed for every elution when using a ⁹⁹Mo/^99mTc generator during QA-QC testing of the final product.

There are alternative routes for generating ⁹⁹Mo that do not require a fissionable target, such as high or low enriched uranium (i.e., HEU or LEU). Some of these include accelerator-based methods, such as proton bombardment or photoneutron reactions on enriched ¹⁰⁰Mo targets. Historically, ⁹⁹Mo generated by neutron capture on natural isotopic molybdenum or enriched ⁹⁸Mo targets was used for the development of commercial ⁹⁹Mo/^99mTc generators.{{Cite conference|last=Richards|first=P.|date=1989|title=Technetium-99m: The early days|conference=3rd International Symposium on Technetium in Chemistry and Nuclear Medicine, Padova, Italy, 5-8 Sep 1989|osti=5612212}}{{Cite report|title=The Technetium-99m Generator|last=Richards|first=P.|date=1965-10-14|doi=10.2172/4589063|osti=4589063 |doi-access=free}} The neutron-capture process was eventually superseded by fission-based ⁹⁹Mo that could be generated with much higher specific activities. Implementing feed-stocks of high specific activity ⁹⁹Mo solutions thus allowed for higher quality production and better separations of ^99mTc from ⁹⁹Mo on small alumina column using chromatography. Employing low-specific activity ⁹⁹Mo under similar conditions is particularly problematic in that either higher Mo loading capacities or larger columns are required for accommodating equivalent amounts of ⁹⁹Mo. Chemically speaking, this phenomenon occurs due to other Mo isotopes present aside from ⁹⁹Mo that compete for surface site interactions on the column substrate. In turn, low-specific activity ⁹⁹Mo usually requires much larger column sizes and longer separation times, and usually yields ^99mTc accompanied by unsatisfactory amounts of the parent radioisotope when using γ-alumina as the column substrate. Ultimately, the inferior end-product ^99mTc generated under these conditions makes it essentially incompatible with the commercial supply-chain.

In the last decade, cooperative agreements between the US government and private capital entities have resurrected neutron capture production for commercially distributed ⁹⁹Mo/^99mTc in the United States of America.{{Cite web|url=https://www.northstarnm.com/|title=Emerging leader with new solutions in the field of nuclear medicine technology|website=NorthStar Medical Radioisotopes, LLC|language=en|access-date=2020-01-23}} The return to neutron-capture-based ⁹⁹Mo has also been accompanied by the implementation of novel separation methods that allow for low-specific activity ⁹⁹Mo to be utilized.

References

Isotopic compositions and standard atomic masses from:
{{CIAAW2003}}
{{CIAAW 2005}}
Half-life, spin, and isomer data selected from the following sources.
{{NUBASE 2003}}
{{NNDC}}
{{CRC85|chapter=11}}

Category:Molybdenum

Molybdenum