ISOTOPES OF ZIRCONIUM

Naturally-occurring 'Zirconium' ('Zr') is composed of four stable isotopes, and one extremely long-lived radioisotope (⁹⁶Zr). The second most stable radioisotope is ⁹³Zr which has a half-life of 1.53 million years. Eighteen other radioisotopes have been observed. Most of these have half-lives that are less than a day except for ⁹⁵Zr (64.02 days), ⁸⁸Zr (63.4 days), and ⁸⁹Zr (78.41 hours). The primary decay mode is electron capture for isotopes lighter than ⁹²Zr, and the primary mode for heavier isotopes is beta decay.

Standard atomic mass: 91.224(2) u

Contents

Table

Notes

References

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)
	excitation energy
78Zr	40	38	77.95523(54)#	50# ms [>170 ns]	0+
79Zr	40	39	78.94916(43)#	56(30) ms	5/2+#
80Zr	40	40	79.9404(16)	4.6(6) s	0+
81Zr	40	41	80.93721(18)	5.5(4) s	(3/2-)#
82Zr	40	42	81.93109(24)#	32(5) s	0+
83Zr	40	43	82.92865(10)	41.6(24) s	(1/2-)#
84Zr	40	44	83.92325(21)#	25.9(7) min	0+
85Zr	40	45	84.92147(11)	7.86(4) min	7/2+
85mZr	292.2(3) keV			10.9(3) s	(1/2-)
86Zr	40	46	85.91647(3)	16.5(1) h	0+
87Zr	40	47	86.914816(9)	1.68(1) h	(9/2)+
87mZr	335.84(19) keV			14.0(2) s	(1/2)-
88Zr	40	48	87.910227(11)	83.4(3) d	0+
89Zr	40	49	88.908890(4)	78.41(12) h	9/2+
89mZr	587.82(10) keV			4.161(17) min	1/2-
90Zr	40	50	89.9047044(25)	STABLE	0+	0.5145(40)
90m1Zr	2319.000(10) keV			809.2(20) ms	5-
90m2Zr	3589.419(16) keV			131(4) ns	8+
91Zr	40	51	90.9056458(25)	STABLE	5/2+	0.1122(5)
91mZr	3167.3(4) keV			4.35(14) µs	(21/2+)
92Zr	40	52	91.9050408(25)	STABLE	0+	0.1715(8)
93Zr	40	53	92.9064760(25)	1.53(10)E+6 a	5/2+
94Zr	40	54	93.9063152(26)	STABLE [>1.1E+17 a]]	0+	0.1738(28)
95Zr	40	55	94.9080426(26)	64.032(6) d	5/2+
96Zr	40	56	95.9082734(30)	24(6)E+18 a	0+	0.0280(9)
97Zr	40	57	96.9109531(30)	16.744(11) h	1/2+
98Zr	40	58	97.912735(21)	30.7(4) s	0+
99Zr	40	59	98.916512(22)	2.1(1) s	1/2+
100Zr	40	60	99.91776(4)	7.1(4) s	0+
101Zr	40	61	100.92114(3)	2.3(1) s	3/2+
102Zr	40	62	101.92298(5)	2.9(2) s	0+
103Zr	40	63	102.92660(12)	1.3(1) s	(5/2-)
104Zr	40	64	103.92878(43)#	1.2(3) s	0+
105Zr	40	65	104.93305(43)#	0.6(1) s
106Zr	40	66	105.93591(54)#	200# ms [>300 ns]	0+
107Zr	40	67	106.94075(32)#	150# ms [>300 ns]
108Zr	40	68	107.94396(64)#	80# ms [>300 ns]	0+
109Zr	40	69	108.94924(54)#	60# ms [>300 ns]
110Zr	40	70	109.95287(86)#	30# ms [>300 ns]	0+

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

★ 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.