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Isotopes of molybdenum

There are 35 known isotopes of Molybdenum (Mo) ranging in atomic mass from 83 to 117, as well as four metastable nuclear isomers. Seven isotopes occur naturally, with atomic masses of 92, 94, 95, 96, 97, 98, and 100. Of these naturally occurring isotopes, five are stable, with atomic masses from 94 to 98. All unstable isotopes of molybdenum decay into isotopes of niobium, technetium, and ruthenium.^[1]

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Molybdenum-92 and molybdenum-100 are the only naturally occurring isotopes which are not stable. Molybdenum-100 has a half-life of approximately 1×10¹⁹ y and undergoes double beta decay into ruthenium-100. Molybdenum-98 is the most common isotope, comprising 24.14% of all molybdenum. Molybdenum isotopes with mass numbers from 111 to 117 all have half-lives of approximately .15 μs.^[1]
Standard atomic mass: 95.94(2) u

Table

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
nuclide symbol	excitation energy			half-life	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
⁸³Mo	42	41	82.94874(54)#	23(19) ms [6(+30-3) ms]	3/2-#
⁸⁴Mo	42	42	83.94009(43)#	3.8(9) ms [3.7(+10-8) s]	0+
⁸⁵Mo	42	43	84.93655(30)#	3.2(2) s	(1/2-)#
⁸⁶Mo	42	44	85.93070(47)	19.6(11) s	0+
⁸⁷Mo	42	45	86.92733(24)	14.05(23) s	7/2+#
⁸⁸Mo	42	46	87.921953(22)	8.0(2) min	0+
⁸⁹Mo	42	47	88.919480(17)	2.11(10) min	(9/2+)
^89mMo	387.5(2) keV			190(15) ms	(1/2-)
⁹⁰Mo	42	48	89.913937(7)	5.56(9) h	0+
^90mMo	2874.73(15) keV			1.12(5) µs	8+#
⁹¹Mo	42	49	90.911750(12)	15.49(1) min	9/2+
^91mMo	653.01(9) keV			64.6(6) s	1/2-
⁹²Mo	42	50	91.906811(4)	STABLE [>190E+18 a]	0+	0.1477(31)
^92mMo	2760.46(16) keV			190(3) ns	8+
⁹³Mo	42	51	92.906813(4)	4.0(8)E+3 a	5/2+
^93mMo	2424.89(3) keV			6.85(7) h	21/2+
⁹⁴Mo	42	52	93.9050883(21)	STABLE	0+	0.0923(10)
⁹⁵Mo	42	53	94.9058421(21)	STABLE	5/2+	0.1590(9)
⁹⁶Mo	42	54	95.9046795(21)	STABLE	0+	0.1668(1)
⁹⁷Mo	42	55	96.9060215(21)	STABLE	5/2+	0.0956(5)
⁹⁸Mo	42	56	97.9054082(21)	STABLE [>100E+12 a]	0+	0.2419(26)
⁹⁹Mo	42	57	98.9077119(21)	2.7489(6) d	1/2+
^99m1Mo	97.785(3) keV			15.5(2) µs	5/2+
^99m2Mo	684.5(4) keV			0.76(6) µs	11/2-
¹⁰⁰Mo	42	58	99.907477(6)	8.5(5)E+18 a	0+	0.0967(20)
¹⁰¹Mo	42	59	100.910347(6)	14.61(3) min	1/2+
¹⁰²Mo	42	60	101.910297(22)	11.3(2) min	0+
¹⁰³Mo	42	61	102.91321(7)	67.5(15) s	(3/2+)
¹⁰⁴Mo	42	62	103.91376(6)	60(2) s	0+
¹⁰⁵Mo	42	63	104.91697(8)	35.6(16) s	(5/2-)
¹⁰⁶Mo	42	64	105.918137(19)	8.73(12) s	0+
¹⁰⁷Mo	42	65	106.92169(17)	3.5(5) s	(7/2-)
^107mMo	66.3(2) keV			470(30) ns	(5/2-)
¹⁰⁸Mo	42	66	107.92345(21)#	1.09(2) s	0+
¹⁰⁹Mo	42	67	108.92781(32)#	0.53(6) s	(7/2-)#
¹¹⁰Mo	42	68	109.92973(43)#	0.27(1) s	0+
¹¹¹Mo	42	69	110.93441(43)#	200# ms [>300 ns]
¹¹²Mo	42	70	111.93684(64)#	150# ms [>300 ns]	0+
¹¹³Mo	42	71	112.94188(64)#	100# ms [>300 ns]
¹¹⁴Mo	42	72	113.94492(75)#	80# ms [>300 ns]	0+
¹¹⁵Mo	42	73	114.95029(86)#	60# ms [>300 ns]

Notes

Geologically exceptional samples are known in which the isotopic composition lies outside the reported range. The uncertainty in the atomic mass may exceed the stated value for such specimens.
Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses.
Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from IUPAC which use expanded uncertainties.

References

^ ^a ^b Lide, David R., ed. (2006), , vol. 11, CRC, pp. 87-88, 0-8493-0487-3

Isotope masses from Ame2003 Atomic Mass Evaluation by G. Audi, A.H. Wapstra, C. Thibault, J. Blachot and O. Bersillon in Nuclear Physics A729 (2003).
Isotopic compositions and standard atomic masses from Atomic weights of the elements. Review 2000 (IUPAC Technical Report). Pure Appl. Chem. Vol. 75, No. 6, pp. 683-800, (2003) and Atomic Weights Revised (2005).
Half-life, spin, and isomer data selected from these sources. Editing notes on this article's talk page.
- Audi, Bersillon, Blachot, Wapstra. The Nubase2003 evaluation of nuclear and decay properties, Nuc. Phys. A 729, pp. 3-128 (2003).
- National Nuclear Data Center, Brookhaven National Laboratory. Information extracted from the NuDat 2.1 database (retrieved Sept. 2005).
- David R. Lide (ed.), Norman E. Holden in CRC Handbook of Chemistry and Physics, 85th Edition, online version. CRC Press. Boca Raton, Florida (2005). Section 11, Table of the Isotopes.

Isotopes of niobium	Isotopes of molybdenum	Isotopes of technetium
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Categories: Isotopes | Molybdenum

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