Isotopes of arsenic

Isotopes of arsenic (₃₃As)
γ	–
β+	74Ge
γ	–
β−	74Se
Standard atomic weight Ar°(As)
	74.921595±0.000006; 74.922±0.001 (abridged);
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Arsenic (₃₃As) has 32 known isotopes and at least 10 isomers. Only one of these isotopes, ⁷⁵As, is stable; as such, it is considered a monoisotopic element. The longest-lived radioisotope is ⁷³As with a half-life of 80 days.

List of isotopes

Nuclide ^{[n 1]}	Z	N	Isotopic mass (Da)^[4] ^{[n 2]}^{[n 3]}	Half-life^[1]	Decay mode^[1] ^{[n 4]}	Daughter isotope ^{[n 5]}^{[n 6]}	Spin and parity^[1] ^{[n 7]}^{[n 8]}	Isotopic abundance
Nuclide ^{[n 1]}	Excitation energy^{[n 8]}			Half-life^[1]	Decay mode^[1] ^{[n 4]}	Daughter isotope ^{[n 5]}^{[n 6]}	Spin and parity^[1] ^{[n 7]}^{[n 8]}	Isotopic abundance
⁶⁴As	33	31	63.95756(22)#	69.0(14) ms	β⁺	⁶⁴Ge	0+#
⁶⁴As	33	31	63.95756(22)#	69.0(14) ms	β⁺, p?	⁶³Ga	0+#
⁶⁵As	33	32	64.949611(91)	130.3(6) ms	β⁺	⁶⁵Ge	3/2−#
⁶⁵As	33	32	64.949611(91)	130.3(6) ms	β⁺, p?	⁶⁴Ga	3/2−#
⁶⁶As	33	33	65.9441488(61)	95.77(23) ms	β⁺	⁶⁶Ge	0+
^66m1As	1356.63(17) keV			1.14(4) μs	IT	⁶⁶As	5+
^66m2As	3023.(3) keV			7.98(26) μs	IT	⁶⁶As	9+
⁶⁷As	33	34	66.93925111(48)	42.5(12) s	β⁺	⁶⁷Ge	(5/2−)
⁶⁸As	33	35	67.9367741(20)	151.6(8) s	β⁺	⁶⁸Ge	3+
^68mAs	425.1(2) keV			111(20) ns	IT	⁶⁸As	1+
⁶⁹As	33	36	68.932246(34)	15.2(2) min	β⁺	⁶⁹Ge	5/2−
⁷⁰As	33	37	69.9309346(15)	52.6(3) min	β⁺	⁷⁰Ge	4+
^70mAs	32.046(23) keV			96(3) μs	IT	⁷⁰As	2+
⁷¹As	33	38	70.9271136(45)	65.30(7) h	β⁺	⁷¹Ge	5/2−
⁷²As	33	39	71.9267523(44)	26.0(1) h	β⁺	⁷²Ge	2−
⁷³As	33	40	72.9238291(41)	80.30(6) d	EC	⁷³Ge	3/2−
^73mAs	427.902(21) keV			5.7(2) μs	IT	⁷³As	9/2+
⁷⁴As	33	41	73.9239286(18)	17.77(2) d	β⁺ (66%)	⁷⁴Ge	2−
⁷⁴As	33	41	73.9239286(18)	17.77(2) d	β⁻ (34%)	⁷⁴Se	2−
⁷⁵As	33	42	74.92159456(95)	Stable			3/2−	1.0000
^75mAs	303.9243(8) keV			17.62(23) ms	IT	⁷⁵As	9/2+
⁷⁶As	33	43	75.92239201(95)	1.0933(38) d	β⁻	⁷⁶Se	2−
^76mAs	44.425(1) keV			1.84(6) μs	IT	⁷⁶As	(1)+
⁷⁷As	33	44	76.9206476(18)	38.79(5) h	β⁻	⁷⁷Se	3/2−
^77mAs	475.48(4) keV			114.0(25) μs	IT	⁷⁷As	9/2+
⁷⁸As	33	45	77.921828(10)	90.7(2) min	β⁻	⁷⁸Se	2−
⁷⁹As	33	46	78.9209484(57)	9.01(15) min	β⁻	⁷⁹Se	3/2−
^79mAs	772.81(6) keV			1.21(1) μs	IT	⁷⁹As	(9/2)+
⁸⁰As	33	47	79.9224744(36)	15.2(2) s	β⁻	⁸⁰Se	1+
⁸¹As	33	48	80.9221323(28)	33.3(8) s	β⁻	⁸¹Se	3/2−
⁸²As	33	49	81.9247387(40)	19.1(5) s	β⁻	⁸²Se	(2−)
^82mAs	131.6(5) keV			13.6(4) s	β⁻	⁸²Se	(5-)
⁸³As	33	50	82.9252069(30)	13.4(4) s	β⁻	⁸³Se	5/2−#
⁸⁴As	33	51	83.9293033(34)	3.16(58) s	β⁻ (99.72%)	⁸⁴Se	(2−)
⁸⁴As	33	51	83.9293033(34)	3.16(58) s	β⁻, n (.28%)	⁸³Se	(2−)
⁸⁵As	33	52	84.9321637(33)	2.022(7) s	β⁻, n (62.6%)	⁸⁴Se	(5/2−)
⁸⁵As	33	52	84.9321637(33)	2.022(7) s	β⁻ (37.4%)	⁸⁵Se	(5/2−)
⁸⁶As	33	53	85.9367015(37)	945(8) ms	β⁻ (64.5%)	⁸⁶Se	(1−,2−)
					β⁻, n (35.5%)	⁸⁵Se
					β⁻, 2n?	⁸⁴Se
⁸⁷As	33	54	86.9402917(32)	492(25) ms	β⁻ (84.6%)	⁸⁷Se	(5/2−,3/2−)
					β⁻, n (15.4%)	⁸⁶Se
					β⁻, 2n?	⁸⁵Se
⁸⁸As	33	55	87.94584(22)#	270(150) ms	β⁻	⁸⁸Se
⁸⁸As	33	55	87.94584(22)#	270(150) ms	β⁻, n?	⁸⁷Se
⁸⁹As	33	56	88.95005(32)#	220# ms [>150 ns]	β⁻?	⁸⁹Se	5/2−#
					β⁻, n?	⁸⁸Se
					β⁻, 2n?	⁸⁷Se
⁹⁰As	33	57	89.95600(43)#	70# ms [>300 ns]	β⁻?	⁹⁰Se
					β⁻, n?	⁸⁹Se
					β⁻, 2n?	⁸⁸Se
^90mAs	124.5(5) keV			220(100) ns	IT	⁹⁰As
⁹¹As	33	58	90.96082(43)#	100# ms [>300 ns]	β⁻?	⁹¹Se	5/2−#
					β⁻, n?	⁹⁰Se
					β⁻, 2n?	⁸⁹Se
⁹²As	33	59	91.96739(54)#	45# ms [>300 ns]	β⁻?	⁹²Se
					β⁻, n?	⁹¹Se
					β⁻, 2n?	⁹⁰Se
⁹³As^[5]	33	60
⁹⁴As^[5]	33	61
⁹⁵As^[5]	33	62
This table header & footer: view

^ ^mAs – Excited nuclear isomer.
^ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
^ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
^ Modes of decay:

EC: Electron capture

n: Neutron emission

p: Proton emission
^ Bold italics symbol as daughter – Daughter product is nearly stable.
^ Bold symbol as daughter – Daughter product is stable.
^ ( ) spin value – Indicates spin with weak assignment arguments.
^ ^a ^b # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).

References

^ ^a ^b ^c ^d 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.
^ "Standard Atomic Weights: Arsenic". CIAAW. 2013.
^ 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.
^ 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.
^ ^a ^b ^c 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). doi:10.1103/PhysRevC.109.044313.

Isotope masses from:
- Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
Half-life, spin, and isomer data selected from the following sources.
- Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
- National Nuclear Data Center. "NuDat 2.x database". Brookhaven National Laboratory.
- Holden, Norman E. (2004). "11. Table of the Isotopes". In Lide, David R. (ed.). CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9.
A.Shore, A. Fritsch, M. Heim, A. Schuh, M. Thoennessen. Discovery of the Arsenic Isotopes. arXiv:0902.4361.

[4] As – Excited nuclear isomer.

[6] ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.

[TMS-7] # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).

[8] Modes of decay:

EC: Electron capture

n: Neutron emission

p: Proton emission

[9] Bold italics symbol as daughter – Daughter product is nearly stable.

[10] Bold symbol as daughter – Daughter product is stable.

[11] ( ) spin value – Indicates spin with weak assignment arguments.

[TNN-12] # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).

[NUBASE2020-1] 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] "Standard Atomic Weights: Arsenic". CIAAW. 2013.

[CIAAW2021-3] 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.

[AME2020_II-5] 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.

[shimizu2024-13] 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). doi:10.1103/PhysRevC.109.044313.

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