Isotopes of germanium

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Germanium (₃₂Ge) has five naturally occurring isotopes, ⁷⁰Ge, ⁷²Ge, ⁷³Ge, ⁷⁴Ge, and ⁷⁶Ge. Of these, ⁷⁶Ge is very slightly radioactive, undergoing double beta decay with a half-life of 2.02 × 10²¹ years^[3] (over 100 billion times the age of the universe).

Quick facts Main isotopes, Decay ...

Isotopes of germanium (₃₂Ge)

Main isotopes^[1]			Decay
Isotope	abundance	half-life (t_1/2)	mode	product
⁶⁸Ge	synth	271.05 d	ε	⁶⁸Ga
⁷⁰Ge	20.5%	stable
⁷¹Ge	synth	11.468 d^[2]	ε	⁷¹Ga
⁷²Ge	27.4%	stable
⁷³Ge	7.76%	stable
⁷⁴Ge	36.5%	stable
⁷⁶Ge	7.75%	2.02×10²¹ y^[3]	β⁻β⁻	⁷⁶Se

Standard atomic weight A_r°(Ge)

72.630±0.008^[4]
72.630±0.008 (abridged)^[5]

Stable ⁷⁴Ge is the most common isotope, having a natural abundance of 36.52%; ⁷⁶Ge is the least common with a natural abundance of 7.75%.

At least 27 additional radioisotopes have also been synthesized ranging in atomic mass from 58 to 89. The most stable of these is ⁶⁸Ge, decaying by electron capture with a half-life of 271.05 days, whose daughter is the medically useful positron-emitting isotope ⁶⁸Ga. (See gallium-68 generator for notes on the source of this isotope, and its medical use.) The next after that is ⁷¹Ge, also decaying by electron capture with half-life 11.468 days,^[2] and the rest are all less than two days, most under two hours.

While most of germanium's radioisotopes decay by beta decay - β⁺ for isotopes lighter than 74-76, and β^- for those heavier - isotopes as heavy as ⁶⁵Ge can also decay by β⁺-delayed proton emission, and those as light as ⁸⁴Ge by β⁻-delayed neutron emission.

⁷⁶Ge is used in experiments on the nature of neutrinos, by searching for neutrinoless double beta decay.

List of isotopes

More information Nuclide, Z ...

Nuclide ^{[n 1]}	Z	N	Isotopic mass (Da)^[6] ^{[n 2]}^{[n 3]}	Discovery year^[7]^[8]	Half-life^[1] ^{[n 4]}^{[n 5]}	Decay mode^[1] ^{[n 6]}	Daughter isotope ^{[n 7]}	Spin and parity^[1] ^{[n 8]}^{[n 5]}	Natural abundance (mole fraction)
Nuclide ^{[n 1]}	Excitation energy			Discovery year^[7]^[8]	Half-life^[1] ^{[n 4]}^{[n 5]}	Decay mode^[1] ^{[n 6]}	Daughter isotope ^{[n 7]}	Spin and parity^[1] ^{[n 8]}^{[n 5]}	Normal proportion^[1]	Range of variation
⁵⁹Ge	32	27	58.98243(43)#	2015	13.3(17) ms	β⁺, p (93%)	⁵⁸Zn	7/2−#
						β⁺ (7%)	⁵⁹Ga
						2p (<0.2%)	⁵⁷Zn
⁶⁰Ge	32	28	59.970286(24)^[9]	2005	25.0(3) ms^[9]	β⁺, p (67%^[9])	⁵⁹Zn	0+
⁶⁰Ge	32	28	59.970286(24)^[9]	2005	25.0(3) ms^[9]	β⁺ (33%^[9])	⁶⁰Ga	0+
⁶¹Ge	32	29	60.96373(32)#	1987	40.7(4) ms	β⁺, p (87%)	⁶⁰Zn	3/2−#
⁶¹Ge	32	29	60.96373(32)#	1987	40.7(4) ms	β⁺ (13%)	⁶¹Ga	3/2−#
⁶²Ge	32	30	61.95463(15)^[9]	1991	73.5(1) ms^[9]	β⁺	⁶²Ga	0+
⁶³Ge	32	31	62.949628(40)	1991	153.6(11) ms	β⁺	⁶³Ga	3/2−#
⁶⁴Ge	32	32	63.9416899(40)	1972	63.7(25) s	β⁺	⁶⁴Ga	0+
⁶⁵Ge	32	33	64.9393681(23)	1972	30.9(5) s	β⁺ (99.99%)	⁶⁵Ga	3/2−
⁶⁵Ge	32	33	64.9393681(23)	1972	30.9(5) s	β⁺, p (0.011%)	⁶⁴Zn	3/2−
⁶⁶Ge	32	34	65.9338621(26)	1950	2.26(5) h	β⁺	⁶⁶Ga	0+
⁶⁷Ge	32	35	66.9327170(46)	1950	18.9(3) min	β⁺	⁶⁷Ga	1/2−
^67m1Ge	18.20(5) keV			1978	13.7(9) μs	IT	⁶⁷Ge	5/2−
^67m2Ge	751.70(6) keV			1978	109.1(38) ns	IT	⁶⁷Ge	9/2+
⁶⁸Ge^{[n 9]}	32	36	67.9280953(20)	1948	271.05(8) d	EC	⁶⁸Ga	0+
⁶⁹Ge	32	37	68.9279645(14)	1938	39.05(10) h	β⁺	⁶⁹Ga	5/2−
^69m1Ge	86.76(2) keV			1964	5.1(2) μs	IT	⁶⁹Ge	1/2−
^69m2Ge	397.94(2) keV			1970	2.81(5) μs	IT	⁶⁹Ge	9/2+
⁷⁰Ge	32	38	69.92424854(88)	1923	Stable			0+	0.2052(19)
⁷¹Ge	32	39	70.92495212(87)	1941	11.468(8) d^[2]	EC	⁷¹Ga	1/2−
^71mGe	198.354(14) keV			1961	20.41(18) ms	IT	⁷¹Ge	9/2+
⁷²Ge	32	40	71.922075824(81)	1923	Stable			0+	0.2745(15)
^72mGe	691.43(4) keV			1949	444.2(8) ns	IT	⁷²Ge	0+
⁷³Ge	32	41	72.923458954(61)	1931	Stable			9/2+	0.0776(8)
^73m1Ge	13.2845(15) keV			1953	2.91(3) μs	IT	⁷³Ge	5/2+
^73m2Ge	66.725(9) keV			1957	499(11) ms	IT	⁷³Ge	1/2−
⁷⁴Ge	32	42	73.921177760(13)	1923	Stable			0+	0.3652(12)
⁷⁵Ge	32	43	74.922858370(55)	1939	82.78(4) min	β⁻	⁷⁵As	1/2−
^75m1Ge	139.69(3) keV			1952	47.7(5) s	IT (99.97%)	⁷⁵Ge	7/2+
^75m1Ge	139.69(3) keV			1952	47.7(5) s	β⁻ (0.030%)	⁷⁵As	7/2+
^75m2Ge	192.19(6) keV			1982	216(5) ns	IT	⁷⁵Ge	5/2+
⁷⁶Ge^{[n 10]}^{[n 11]}	32	44	75.921402725(19)	1931	(2.022±0.018±0.038)×10²¹ y^[3]	β⁻β⁻	⁷⁶Se	0+	0.0775(12)
⁷⁷Ge	32	45	76.923549843(56)	1939	11.211(3) h	β⁻	⁷⁷As	7/2+
^77mGe	159.71(6) keV			1947	53.7(6) s	β⁻ (81%)	⁷⁷As	1/2−
^77mGe	159.71(6) keV			1947	53.7(6) s	IT (19%)	⁷⁷Ge	1/2−
⁷⁸Ge	32	46	77.9228529(38)	1951	88.0(10) min	β⁻	⁷⁸As	0+
⁷⁹Ge	32	47	78.925360(40)	1970	18.98(3) s	β⁻	⁷⁹As	(1/2)−
^79mGe	185.95(4) keV			1974	39.0(10) s	β⁻ (96%)	⁷⁹As	7/2+#
^79mGe	185.95(4) keV			1974	39.0(10) s	IT (4%)	⁷⁹Ge	7/2+#
⁸⁰Ge	32	48	79.9253508(22)	1972	29.5(4) s	β⁻	⁸⁰As	0+
⁸¹Ge	32	49	80.9288329(22)	1972	9(2) s	β⁻	⁸¹As	9/2+#
^81mGe	679.14(4) keV			1981	6(2) s	β⁻	⁸¹As	(1/2+)
^81mGe	679.14(4) keV			1981	6(2) s	IT (<1%)	⁸¹Ge	(1/2+)
⁸²Ge	32	50	81.9297740(24)	1972	4.31(19) s	β⁻	⁸²As	0+
⁸³Ge	32	51	82.9345391(26)	1972	1.85(6) s	β⁻	⁸³As	(5/2+)
⁸⁴Ge	32	52	83.9375751(34)	1972	951(9) ms	β⁻ (89.4%)	⁸⁴As	0+
⁸⁴Ge	32	52	83.9375751(34)	1972	951(9) ms	β⁻, n (10.6%)	⁸³As	0+
⁸⁵Ge	32	53	84.9429697(40)	1991	495(5) ms	β⁻ (82.8%)	⁸⁵As	(3/2+,5/2+)#
⁸⁵Ge	32	53	84.9429697(40)	1991	495(5) ms	β⁻, n (17.2%)	⁸⁴As	(3/2+,5/2+)#
⁸⁶Ge	32	54	85.94697(47)	1994	221.6(11) ms	β⁻ (55%)	⁸⁶As	0+
⁸⁶Ge	32	54	85.94697(47)	1994	221.6(11) ms	β⁻, n (45%)	⁸⁵As	0+
⁸⁷Ge	32	55	86.95320(32)#	1997	103(4) ms	β⁻	⁸⁷As	5/2+#
⁸⁸Ge	32	56	87.95757(43)#	1997	61(6) ms	β⁻	⁸⁸As	0+
⁸⁹Ge	32	57	88.96453(43)#	1997	60# ms [>300 ns]			3/2+#
⁹⁰Ge	32	58	89.96944(54)#	2010	30# ms [>400 ns]			0+
⁹¹Ge^[10]	32	59		2024
⁹²Ge^[10]	32	60		2024
This table header & footer: view

[1]
^mGe – Excited nuclear isomer.
[2]
( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
[3]
# – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
[4]
Bold half-life – nearly stable, half-life longer than age of universe.
[5]
# – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
[6]
Modes of decay:

EC: Electron capture

IT: Isomeric transition

n: Neutron emission

p: Proton emission
[7]
Bold symbol as daughter – Daughter product is stable.
[8]
( ) spin value – Indicates spin with weak assignment arguments.
[9]
Used to generate ⁶⁸Ga
[10]
Fission product
[11]
Primordial radionuclide

References

[1]
Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3) 030001. doi:10.1088/1674-1137/abddae.
[2]
Norman, E. B.; Drobizhev, A.; Gharibyan, N.; Gregorich, K. E.; Kolomensky, Yu. G.; Sammis, B. N.; Scielzo, N. D.; Shusterman, J. A.; Thomas, K. J. (30 May 2024). "Half-life of Ge 71 and the gallium anomaly". Physical Review C. 109 (5). doi:10.1103/PhysRevC.109.055501.
[3]
M. Agostini; et al. (2023-10-03). "Final Results of GERDA on the Two-Neutrino Double-β Decay Half-Life of ⁷⁶Ge". Physical Review Letters. 131 (14) 142501. American Physical Society (APS). arXiv:2308.09795. Bibcode:2023PhRvL.131n2501A. doi:10.1103/physrevlett.131.142501. ISSN 0031-9007. PMID 37862664. S2CID 261049638.
[4]
"Standard Atomic Weights: Germanium". CIAAW. 2009.
[5]
Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
[6]
Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3) 030003. doi:10.1088/1674-1137/abddaf.
[7]
FRIB Nuclear Data Group. "Discovery of Nuclides Project, Isotope Database". doi:10.11578/frib/2279152.
[8]
FRIB Nuclear Data Group. "Discovery of Nuclides Project, Isomer Database". doi:10.11578/frib/2572219.
[9]
Orrigo, S. E. A.; Rubio, B.; Gelletly, W.; Aguilera, P.; Algora, A.; Morales, A. I.; Agramunt, J.; Ahn, D. S.; Ascher, P.; Blank, B.; Borcea, C.; Boso, A.; Cakirli, R. B.; Chiba, J.; de Angelis, G.; de France, G.; Diel, F.; Doornenbal, P.; Fujita, Y.; Fukuda, N.; Ganioğlu, E.; Gerbaux, M.; Giovinazzo, J.; Go, S.; Goigoux, T.; Grévy, S.; Guadilla, V.; Inabe, N.; Kiss, G. G.; Kubo, T.; Kubono, S.; Kurtukian-Nieto, T.; Lubos, D.; Magron, C.; Molina, F.; Montaner-Pizá, A.; Napoli, D.; Nishimura, D.; Nishimura, S.; Oikawa, H.; Phong, V. H.; Sakurai, H.; Shimizu, Y.; Sidong, C.; Söderström, P.-A.; Sumikama, T.; Suzuki, H.; Takeda, H.; Takei, Y.; Tanaka, M.; Wu, J.; Yagi, S. (29 January 2021). "β decay of the very neutron-deficient Ge 60 and Ge 62 nuclei". Physical Review C. 103 (1) 014324. arXiv:2008.10576. doi:10.1103/PhysRevC.103.014324.
[10]
Shimizu, Y.; Kubo, T.; Sumikama, T.; Fukuda, N.; Takeda, H.; Suzuki, H.; Ahn, D. S.; Inabe, N.; Kusaka, K.; Ohtake, M.; Yanagisawa, Y.; Yoshida, K.; Ichikawa, Y.; Isobe, T.; Otsu, H.; Sato, H.; Sonoda, T.; Murai, D.; Iwasa, N.; Imai, N.; Hirayama, Y.; Jeong, S. C.; Kimura, S.; Miyatake, H.; Mukai, M.; Kim, D. G.; Kim, E.; Yagi, A. (8 April 2024). "Production of new neutron-rich isotopes near the N = 60 isotones Ge 92 and As 93 by in-flight fission of a 345 MeV/nucleon U 238 beam". Physical Review C. 109 (4) 044313. doi:10.1103/PhysRevC.109.044313.

Isotopes of germanium

List of isotopes

See also

References

Related Articles

EC:	Electron capture
IT:	Isomeric transition
n:	Neutron emission
p:	Proton emission