Isotopes of arsenic

Isotopes of arsenic
Arsenic (33As) has 33 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. Arsenic has been proposed as a "salting" material for nuclear weapons (cobalt is another, better-known salting material). A jacket of 75As, irradiated by the intense high-energy neutron flux from an exploding thermonuclear weapon, would transmute into the radioactive isotope 76As with a half-life of 1.0778 days and produce approximately 1.13 MeV gamma radiation, significantly increasing the radioactivity of the weapon's fallout for several hours. Such a weapon is not known to have ever been built, tested, or used.
Transmutation of arsenic to much less toxic selenium could prevent cycling of arsenic, from groundwater to waterways to oceans and back via Sargassum seaweeds. Bioremediation can provide a large supply of arsenic and rid aquifers of persistent poisoning issues.
List of isotopes
|-
| 60As
| style="text-align:right" | 33
| style="text-align:right" | 27
| 59.99313(64)#
|
| p
| 59Ge
| 5+#
|
|
|-
| 61As
| style="text-align:right" | 33
| style="text-align:right" | 28
| 60.98062(64)#
|
| p
| 60Ge
| 3/2−#
|
|
|-
| 62As
| style="text-align:right" | 33
| style="text-align:right" | 29
| 61.97320(32)#
|
| p
| 61Ge
| 1+#
|
|
|-
| 63As
| style="text-align:right" | 33
| style="text-align:right" | 30
| 62.96369(54)#
|
| p
| 62Ge
| (3/2−)#
|
|
|-
| 64As
| style="text-align:right" | 33
| style="text-align:right" | 31
| 63.95757(38)#
| 40(30) ms[18(+43-7) ms]
| β+
| 64Ge
| 0+#
|
|
|-
| 65As
| style="text-align:right" | 33
| style="text-align:right" | 32
| 64.94956(32)#
| 170(30) ms
| β+
| 65Ge
| 3/2−#
|
|
|-
| 66As
| style="text-align:right" | 33
| style="text-align:right" | 33
| 65.94471(73)
| 95.77(23) ms
| β+
| 66Ge
| (0+)
|
|
|-
| style="text-indent:1em" | 66m1As
| colspan="3" style="text-indent:2em" | 1356.70(17) keV
| 1.1(1) µs
|
|
| (5+)
|
|
|-
| style="text-indent:1em" | 66m2As
| colspan="3" style="text-indent:2em" | 3023.9(3) keV
| 8.2(5) µs
|
|
| (9+)
|
|
|-
| 67As
| style="text-align:right" | 33
| style="text-align:right" | 34
| 66.93919(11)
| 42.5(12) s
| β+
| 67Ge
| (5/2−)
|
|
|-
| 68As
| style="text-align:right" | 33
| style="text-align:right" | 35
| 67.93677(5)
| 151.6(8) s
| β+
| 68Ge
| 3+
|
|
|-
| style="text-indent:1em" | 68mAs
| colspan="3" style="text-indent:2em" | 425.21(16) keV
| 111(20) ns[?107(+23-16) ns]
|
|
| 1+
|
|
|-
| 69As
| style="text-align:right" | 33
| style="text-align:right" | 36
| 68.93227(3)
| 15.2(2) min
| β+
| 69Ge
| 5/2−
|
|
|-
| 70As
| style="text-align:right" | 33
| style="text-align:right" | 37
| 69.93092(5)
| 52.6(3) min
| β+
| 70Ge
| 4(+#)
|
|
|-
| style="text-indent:1em" | 70mAs
| colspan="3" style="text-indent:2em" | 32.008(23) keV
| 96(3) µs
|
|
| 2(+)
|
|
|-
| 71As
| style="text-align:right" | 33
| style="text-align:right" | 38
| 70.927112(5)
| 65.28(15) h
| β+
| 71Ge
| 5/2−
|
|
|-
| 72As
| style="text-align:right" | 33
| style="text-align:right" | 39
| 71.926752(5)
| 26.0(1) h
| β+
| 72Ge
| 2−
|
|
|-
| 73As
| style="text-align:right" | 33
| style="text-align:right" | 40
| 72.923825(4)
| 80.30(6) d
| EC
| 73Ge
| 3/2−
|
|
|-
| rowspan=2|74As
| rowspan=2 style="text-align:right" | 33
| rowspan=2 style="text-align:right" | 41
| rowspan=2|73.9239287(25)
| rowspan=2|17.77(2) d
| β+ (66%)
| 74Ge
| rowspan=2|2−
| rowspan=2|
| rowspan=2|
|-
| β− (34%)
| 74Se
|-
| 75As
| style="text-align:right" | 33
| style="text-align:right" | 42
| 74.9215965(20)
| colspan=3 align=center|Stable
| 3/2−
| 1.0000
|
|-
| style="text-indent:1em" | 75mAs
| colspan="3" style="text-indent:2em" | 303.9241(7) keV
| 17.62(23) ms
|
|
| 9/2+
|
|
|-
| rowspan=2|76As
| rowspan=2 style="text-align:right" | 33
| rowspan=2 style="text-align:right" | 43
| rowspan=2|75.922394(2)
| rowspan=2|1.0942(7) d
| β− (99.98%)
| 76Se
| rowspan=2|2−
| rowspan=2|
| rowspan=2|
|-
| EC (.02%)
| 76Ge
|-
| style="text-indent:1em" | 76mAs
| colspan="3" style="text-indent:2em" | 44.425(1) keV
| 1.84(6) µs
|
|
| (1)+
|
|
|-
| 77As
| style="text-align:right" | 33
| style="text-align:right" | 44
| 76.9206473(25)
| 38.83(5) h
| β−
| 77mSe
| 3/2−
|
|
|-
| style="text-indent:1em" | 77mAs
| colspan="3" style="text-indent:2em" | 475.443(16) keV
| 114.0(25) µs
|
|
| 9/2+
|
|
|-
| 78As
| style="text-align:right" | 33
| style="text-align:right" | 45
| 77.921827(11)
| 90.7(2) min
| β−
| 78Se
| 2−
|
|
|-
| 79As
| style="text-align:right" | 33
| style="text-align:right" | 46
| 78.920948(6)
| 9.01(15) min
| β−
| 79mSe
| 3/2−
|
|
|-
| style="text-indent:1em" | 79mAs
| colspan="3" style="text-indent:2em" | 772.81(6) keV
| 1.21(1) µs
|
|
| (9/2)+
|
|
|-
| 80As
| style="text-align:right" | 33
| style="text-align:right" | 47
| 79.922534(25)
| 15.2(2) s
| β−
| 80Se
| 1+
|
|
|-
| 81As
| style="text-align:right" | 33
| style="text-align:right" | 48
| 80.922132(6)
| 33.3(8) s
| β−
| 81mSe
| 3/2−
|
|
|-
| 82As
| style="text-align:right" | 33
| style="text-align:right" | 49
| 81.92450(21)
| 19.1(5) s
| β−
| 82Se
| (1+)
|
|
|-
| style="text-indent:1em" | 82mAs
| colspan="3" style="text-indent:2em" | 250(200) keV
| 13.6(4) s
| β−
| 82Se
| (5-)
|
|
|-
| 83As
| style="text-align:right" | 33
| style="text-align:right" | 50
| 82.92498(24)
| 13.4(3) s
| β−
| 83mSe
| 3/2−#
|
|
|-
| rowspan=2|84As
| rowspan=2 style="text-align:right" | 33
| rowspan=2 style="text-align:right" | 51
| rowspan=2|83.92906(32)#
| rowspan=2|4.02(3) s
| β− (99.721%)
| 84Se
| rowspan=2|(3)(+#)
| rowspan=2|
| rowspan=2|
|-
| β−, n (.279%)
| 83Se
|-
| style="text-indent:1em" | 84mAs
| colspan="3" style="text-indent:2em" | 0(100)# keV
| 650(150) ms
|
|
|
|
|
|-
| rowspan=2|85As
| rowspan=2 style="text-align:right" | 33
| rowspan=2 style="text-align:right" | 52
| rowspan=2|84.93202(21)#
| rowspan=2|2.021(10) s
| β−, n (59.4%)
| 84Se
| rowspan=2|(3/2−)#
| rowspan=2|
| rowspan=2|
|-
| β− (40.6%)
| 85Se
|-
| rowspan=2|86As
| rowspan=2 style="text-align:right" | 33
| rowspan=2 style="text-align:right" | 53
| rowspan=2|85.93650(32)#
| rowspan=2|0.945(8) s
| β− (67%)
| 86Se
| rowspan=2|
| rowspan=2|
| rowspan=2|
|-
| β−, n (33%)
| 85Se
|-
| rowspan=2|87As
| rowspan=2 style="text-align:right" | 33
| rowspan=2 style="text-align:right" | 54
| rowspan=2|86.93990(32)#
| rowspan=2|0.56(8) s
| β− (84.6%)
| 87Se
| rowspan=2|3/2−#
| rowspan=2|
| rowspan=2|
|-
| β−, n (15.4%)
| 86Se
|-
| rowspan=2|88As
| rowspan=2 style="text-align:right" | 33
| rowspan=2 style="text-align:right" | 55
| rowspan=2|87.94494(54)#
| rowspan=2|300# ms[>300 ns]
| β−
| 88Se
| rowspan=2|
| rowspan=2|
| rowspan=2|
|-
| β−, n
| 87Se
|-
| 89As
| style="text-align:right" | 33
| style="text-align:right" | 56
| 88.94939(54)#
| 200# ms[>300 ns]
| β−
| 89Se
| 3/2−#
|
|
|-
| 90As
| style="text-align:right" | 33
| style="text-align:right" | 57
| 89.95550(86)#
| 80# ms[>300 ns]
|
|
|
|
|
|-
| 91As
| style="text-align:right" | 33
| style="text-align:right" | 58
| 90.96043(97)#
| 50# ms[>300 ns]
|
|
| 3/2−#
|
|
|-
| 92As
| style="text-align:right" | 33
| style="text-align:right" | 59
| 91.96680(97)#
| 30# ms[>300 ns]
|
|
|
|
|
References
Isotope masses from:
Isotopic compositions and standard atomic masses from:
Half-life, spin, and isomer data selected from the following sources.
A.Shore, A. Fritsch, M. Heim, A. Schuh, M. Thoennessen. Discovery of the Arsenic Isotopes. arXiv:0902.4361.
External links
Arsenic
Arsenic