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Isotopes of Astatine

List, data and properties of all known isotopes of Astatine as well as radioactive decay products and intermediate products.

 

Astatine isotopes

All atomic nuclei of the chemical element astatine are summarized under astatine isotopes; these consist of an atomic nucleus with 85 protons and, in the uncharged state, 85 electrons. The difference between the individual astatine isotopes lies in the number of neutrons in the nucleus.

More than 20 isotopes of the chemical element astatine are known, but they are all unstable and very short-lived; the nuclide At-210 has the longest lifetime with a half-life of 8.3 hours.

In nature, astatine isotopes occur within natural radioactive decay chains; Astatine is considered the rarest naturally occurring element.

Certain astatine isotopes can be artificially produced by bombarding bismuth atoms with α-particles. There are no practical applications for the element; However, in 2008 an article appeared on the potential of astatine-211 therapy in prostate cancer [Michael J. Willhauck et al., 2008].

 

Isotope Table: Astatine

 

Atomic Properties

Isotope
Nuclide
ZANNameAtomic Mass
[Nuclear Mass]
{Mass Excess}
Spin I
(h/2π)
μParent
123456789
191At85191106Astatine-191191.004148(17) u
[190.9575243 u]
{3.86384 MeV}
(1/2+)
191mAt85191106Astatine-191m191.004148(17) u
[190.9575243 u]
{3.86384 MeV}
(7/2-)
192At85192107Astatine-192192.00314(3) u
[191.9565163 u]
{2.92489 MeV}
(9-,10-)
192mAt85192107Astatine-192m192.00314(3) u
[191.9565163 u]
{2.92489 MeV}
193At85193108Astatine-193192.999928(23) u
[192.9533043 u]
{-0.06707 MeV}
(1/2+)
193m1At85193108Astatine-193m1192.999928(23) u
[192.9533043 u]
{-0.06707 MeV}
(7/2-)
193m2At85193108Astatine-193m2192.999928(23) u
[192.9533043 u]
{-0.06707 MeV}
(13/2+)
194At85194109Astatine-194193.999227(2) u
[193.9526033 u]
{-0.72004 MeV}
194mAt85194109Astatine-194m193.999227(2) u
[193.9526033 u]
{-0.72004 MeV}
195At85195110Astatine-195194.996274(10) u
[194.9496503 u]
{-3.47075 MeV}
(1/2+)199Fr
195mAt85195110Astatine-195m194.996274(10) u
[194.9496503 u]
{-3.47075 MeV}
(7/2-)
196At85196111Astatine-196195.99580(3) u
[195.9491763 u]
{-3.91227 MeV}
(3+)200Fr
196mAt85196111Astatine-196m195.99580(3) u
[195.9491763 u]
{-3.91227 MeV}
(5+)
197At85197112Astatine-197196.993177(9) u
[196.9465533 u]
{-6.35558 MeV}
(9/2-)201Fr
197mAt85197112Astatine-197m196.993177(9) u
[196.9465533 u]
{-6.35558 MeV}
(1/2+)
198At85198113Astatine-198197.992792(6) u
[197.9461683 u]
{-6.71421 MeV}
(3+)202Fr
198mAt85198113Astatine-198m197.992792(6) u
[197.9461683 u]
{-6.71421 MeV}
(10-)
199At85199114Astatine-199198.990528(6) u
[198.9439043 u]
{-8.82311 MeV}
(9/2-)203Fr
200At85200115Astatine-200199.990351(26) u
[199.9437273 u]
{-8.98799 MeV}
(3+)204Fr
200m1At85200115Astatine-200m1199.990351(26) u
[199.9437273 u]
{-8.98799 MeV}
(7+)
200m2At85200115Astatine-200m2199.990351(26) u
[199.9437273 u]
{-8.98799 MeV}
(10-)
201At85201116Astatine-201200.988417(9) u
[200.9417933 u]
{-10.7895 MeV}
(9/2-)205Fr
202At85202117Astatine-202201.98863(3) u
[201.9420063 u]
{-10.59109 MeV}
(2+,3+)206Fr
202m1At85202117Astatine-202m1201.98863(3) u
[201.9420063 u]
{-10.59109 MeV}
(7+)
202m2At85202117Astatine-202m2201.98863(3) u
[201.9420063 u]
{-10.59109 MeV}
(10-)
203At85203118Astatine-203202.986943(11) u
[202.9403193 u]
{-12.16252 MeV}
9/2-207Fr
204At85204119Astatine-204203.987251(24) u
[203.9406273 u]
{-11.87562 MeV}
7+208Fr
204mAt85204119Astatine-204m203.987251(24) u
[203.9406273 u]
{-11.87562 MeV}
10-
205At85205120Astatine-205204.986074(16) u
[204.9394503 u]
{-12.97199 MeV}
9/2-209Fr
205Rn
205mAt85205120Astatine-205m204.986074(16) u
[204.9394503 u]
{-12.97199 MeV}
29/2+
206At85206121Astatine-206205.986656(16) u
[205.9400323 u]
{-12.42986 MeV}
(5)+210Fr
206Rn
207At85207122Astatine-207206.985800(13) u
[206.9391763 u]
{-13.22721 MeV}
9/2-211Fr
207Rn
208At85208123Astatine-208207.986613(10) u
[207.9399893 u]
{-12.46991 MeV}
6+212Fr
208Rn
209At85209124Astatine-209208.986170(5) u
[208.9395463 u]
{-12.88256 MeV}
9/2-213Fr
209Rn
209mAt85209124Astatine-209m208.986170(5) u
[208.9395463 u]
{-12.88256 MeV}
29/2+15.38(14)
210At85210125Astatine-210209.987147(8) u
[209.9405233 u]
{-11.97249 MeV}
(5)+214Fr
210Rn
210m1At85210125Astatine-210m1209.987147(8) u
[209.9405233 u]
{-11.97249 MeV}
(15)-+15.675(17)
210m2At85210125Astatine-210m2209.987147(8) u
[209.9405233 u]
{-11.97249 MeV}
(19)+13.26(13)
211At85211126Astatine-211210.9874961(29) u
[210.9408724 u]
{-11.64731 MeV}
9/2-215Fr
211Rn
211mAt85211126Astatine-211m210.9874961(29) u
[210.9408724 u]
{-11.64731 MeV}
(39/2-)13.46(14)
212At85212127Astatine-212211.9907372(26) u
[211.9441135 u]
{-8.62824 MeV}
(1-)216Fr
212m1At85212127Astatine-212m1211.9907372(26) u
[211.9441135 u]
{-8.62824 MeV}
(9-)
212m2At85212127Astatine-212m2211.9907372(26) u
[211.9441135 u]
{-8.62824 MeV}
(25-)
213At85213128Astatine-213212.992937(5) u
[212.9463133 u]
{-6.57914 MeV}
9/2-217Fr
214At85214129Astatine-214213.996372(5) u
[213.9497483 u]
{-3.37946 MeV}
1-218Fr
214m1At85214129Astatine-214m1213.996372(5) u
[213.9497483 u]
{-3.37946 MeV}
214m2At85214129Astatine-214m2213.996372(5) u
[213.9497483 u]
{-3.37946 MeV}
9-
215At85215130Astatine-215214.998652(7) u
[214.9520283 u]
{-1.25565 MeV}
9/2-219Fr
215Po
216At85216131Astatine-216216.002423(4) u
[215.9557993 u]
{2.25701 MeV}
1-220Fr
216mAt85216131Astatine-216m216.002423(4) u
[215.9557993 u]
{2.25701 MeV}
(9-)
217At85217132Astatine-217217.004718(5) u
[216.9580943 u]
{4.39479 MeV}
9/2-221Fr
218At85218133Astatine-218218.008694(12) u
[217.9620703 u]
{8.09841 MeV}
218Po
219At85219134Astatine-219219.011161(3) u
[219011160.95338 u]
{204007378407.35 MeV}
(9/2-)223Fr
220At85220135Astatine-220220.015433(15) u
[219.9688093 u]
{14.37575 MeV}
3
221At85221136Astatine-221221.018017(15) u
[220.9713933 u]
{16.78273 MeV}
222At85222137Astatine-222222.022494(17) u
[221.9758703 u]
{20.95303 MeV}
223At85223138Astatine-223223.025151(15) u
[222.9785273 u]
{23.42801 MeV}
224At85224139Astatine-224224.029749(24) u
[223.9831253 u]
{27.71102 MeV}
225At85225140Astatine-225225.03263(32) u
[224.9860063 u]
{30.39465 MeV}
226At85226141Astatine-226226.03716(32) u
[225.9905363 u]
{34.61432 MeV}
227At85227142Astatine-227227.04024(32) u
[226.9936163 u]
{37.48332 MeV}
228At85228143Astatine-228228.04475(43) u
[227.9981263 u]
{41.68436 MeV}
229At85229144Astatine-229229.04812(43) u
[229.0014963 u]
{44.82349 MeV}

 

Radioactive Decay Properties

IsotopeRadioactive DecayAEExtern
Half-lifeDecay ModeProbabilityEnergy
1101112131415
At-191ca. 1.7 msα → 187Bi100 %7.822(14) MeVAL
At-191mca. 2.1 msα → 187Bi100 %55(30)keVAL
At-19288(6) msα → 188Bi≤ 100 %7.696(26) MeV+x keVAL
At-192m11.5(6) msα → 188Bi≤ 100 %+y keVAL
At-193ca. 28 msα → 189Bi100 %7.572(7) MeVAL
At-193m121(5) msα → 189Bi100 %5(10) kevAL
At-193m2ca. 27 msα → 189Bi
Iso → 193At
24(10) %
76(10) %

39(7) keV
At-194ca. 40 msα → 190Bi
EC/β+194Po
?
?
7.454(11) MeV
10.284(28) MeV
AL
At-194mca. 250 msα → 190Bi
EC/β+194Po
Iso → 194At
?
?
?


+y keVAL
At-195290(20) msα → 191Bi100 %7.344(6) MeVAL
At-195m143(3) msα → 191Bi
Iso → 195At
88(4) %
12(4) %

33.0(10) keVAL
At-196388(7) msα → 192Bi
EC/β+196Po
95.1 %
4.9 %
7.195(3) MeV
9.56(3) MeV
AL
At-196m11(2) μs157.9(1) keV
At-197388(6) msα → 193Bi
EC/β+197Po
96.1(12) %
3.9(12) %
7.104(3) MeV
7.00(5) MeV
AL
At-197m2.0(2) sα → 193Bi
EC/β+197Po
Iso → 197At
< 100 %
?
< 0.004 %


52(10) keVAL
At-1984.2(2) sα → 194Bi
EC/β+198Po
90(10) %
10(10) %
6.8894(19) MeV
8.759(18) MeV
AL
At-198m1.21(6) sα → 194Bi
EC/β+198Po
84(16) %
16(16) %

102+x keVAL
At-1997.03(15) sα → 195Bi
EC/β+199Po
90(5) %
10(5) %
6.7773(11) MeV
6.385(19) MeV
AL
At-20043(1) sα → 196Bi
EC/β+200Po
52(3) %
48(3) %
6.5962(13) MeV
7.954(26) MeV
AL
At-200m147(1) sα → 196Bi
EC/β+200Po
43(7) %
≤ 57 %

112(5) keVAL
At-200m2ca. 7.3 sα → 196Bi
Iso, EC/β+
ca. 10.5 %
89.5 %

344(5) keVAL
At-20185.2(16) sα → 197Bi
EC/β+201Po
71(7) %
29(7) %
6.4728(16) MeV
5.732(10) MeV
AL
At-202184(1) sα → 198Bi
EC/β+202Po
37(7) %
63(7) %
6.3538(13) MeV
7.351(29) MeV
AL
At-202m1182(2) sα → 198Bi
EC/β+202Po
8.7(15) %
91.3(15) %

+x keVAL
At-202m20.46(5) sα → 198Bi
Iso → 202At
0.096(11) %
99.90(1) %

391.7(2)+x keVAL
At-2037.4(2) minα → 199Bi
EC/β+203Po
31(3) %
69(3) %
6.2101(8) MeV
5.148(14) MeV
AL
At-2049.12(11) minα → 200Bi
EC/β+204Po
3.91(16) %
96.09(16) %
6.0704(12) MeV
6.466(25) MeV
AL
At-204m108(10) msIso → 204At100 %587.3(2) keVAL
At-20526.9(8) minα → 201Bi
EC/β+205Po
10(2) %
90(2) %
6.0196(17) MeV
4.549(18) MeV
AL
At-205m7.76(14) μs2339.65(23) keV
At-20630.6(8) minα → 202Bi
EC/β+206Po
0.90(8) %
99.10(8) %
5.887(5) MeV
5.759(16) MeV
AL
At-2071.81(3) hα → 203Bi
EC/β+207Po
8.6(10) %
91.4(10) %
5.872(3) MeV
3.918(14) MeV
AL
At-2081.63(3) hα → 204Bi
EC/β+208Po
0.55(6) %
99.45(6) %
5.7511(22) MeV
5.000(9) MeV
AL
At-2095.42(5) hα → 205Bi
EC/β+209Po
4.1(5) %
95.9(5) %
5.7570(20) MeV
3.483(5) MeV
AL
At-209m0.916(10) μs2429.32(22) keV
At-2108.1(4) hα → 206Bi
EC/β+210Po
0.175(20) %
99.825(20) %
5.6312(10) MeV
3.981(8) MeV
AL
At-210m10.482(6) μs2549.6(2) keV
At-210m25.66(7) μs4027.7(2) keV
At-2117.214(7) hα → 207Bi
EC → 211Po
41.80(8) %
58.20(8) %
5.9824(13) MeV
0.785(3) MeV
AL
At-211m4.23(7) μsIso → 211At100 %4814.5(5) keV
At-212314(2) msα → 208Bi
EC/β+212Po
β-212Rn
> 99 %
<< 1 %
<< 1 %
7.8171(6) MeV
1.7413(26) MeV
0.031(4) MeV
AL
At-212m1119(3) msα → 208Bi
Iso → 212At
> 99 %
≤ 1 %

223(7) keVAL
At-212m2152(5) μsIso → 212At4771.6(11) keV
At-213125(6) nsα → 209Bi100 %9.254(5) MeVAL
At-214558(10) nsα → 210Bi100 %8.987(4) MeVAL
At-214m1265(20) nsα → 210Bi< 100 %59(9) keV
At-214m2760(15) nsα → 210Bi≤ 100 %232(6) keV
At-2150.10(2) msα → 211Bi100 %8.178(4) MeVAL
At-2160.30(3) msα → 212Bi
EC → 216Po
β-216Rn
> 99 %
<< 1 %
<< 1%
7.950(3) MeV
0.474(4) MeV
2.004(7) MeV
AL
At-216m0.1 msα → 212Bi100 %413 keV
At-21732.6(3) msα → 213Bi
β-217Rn
99.993(3) %
0.007(3) %
7.2013(12) MeV
0.736(6) MeV
AL
At-2181.5(3) sα → 214Bi
β-218Rn
99.9 %
0.1 %
6.874(3) MeV
2.881(12) MeV
AL
At-21956(3) sα → 215Bi
β-219Rn
93.6(10) %
6.4(10) %
6.342(5) MeV
1.5667(29) MeV
AL
At-2203.71(4) minα → 216Bi
β-220Rn
8(2) %
92(2) %
6.077(18) MeV
3.764(14) MeV
AL
At-2212.3(2) minβ-221Rn100 %2.311(15) MeVAL
At-22254(10) sβ-222Rn100 %4.581(16) MeVAL
At-22350(7) sβ-223Rn100 %3.038(16) MeVAL
At-2241.3 minβ-224Rn?5.266(24) MeVAL
At-225> 300 nsβ-225Rn?3.86(30) MeVAL
At-226> 300 nsβ-226Rn?5.87(30) MeVAL
At-227> 300 nsβ-227Rn
β-, n → 226Rn
?
?
4.60(30) MeV
0.66(30) MeV
AL
At-228> 300 nsβ-228Rn?6.44(40) MeVAL
At-229> 300 nsβ-229Rn
β-, n → 228Rn
?
?
5.46(40) MeV
1.51(40) MeV
AL

 

Notes (related to the columns):

1 - nuclide, isotope symbol.
2 - Z = number of protons (atomic number).
3 - Mass number A.
4 - N = number of neutrons.
5 - Identification of the Astatine isotope.
6 - Relative atomic mass of the Astatine isotope (isotopic mass including electrons) and the mass of the atomic nucleus in square brackets (nuclear mass, nuclide mass without electrons), each related to 12C = 12.00000 [2]. In addition, the mass excess is given in MeV.
7 - Nuclear spin I, unit: h/2π.
8 - Nuclear magnetic moment μmag.
9 - Source nuclides: Possible, assumed or actual source nuclides (mother nuclides, parent nuclides). If applicable, the corresponding decay modes can be found in the data for the respective starting nuclide.
10 - Decay: Half-live of the Astatine isotope (a = years; ; d = days; h = hours; min = minutes; s = seconds).
11 - Decay: type of decay into the respective daughter nuclides with n = neutron emission; p = proton emission; α = alpha decay; β- = beta minus decay with electron emission; EC = electron capture; β+ = positron emission; ε = β+ and/or EC; Iso = isomeric transition; CD = cluster decay; SF = spontaneous decay.
12 - Decay percentage in percent (%).
13 - Decay energy; Particle energy related to decay type.
14 - AE = Excitation energy for metastable nuclei.
15 - Other information and notes: AL = Adopted Levels (link to external data [1]).

Miscellaneous:

()- Numbers in brackets: uncertainty to represent the spread of the reported value.
~ - Theoretical values or systematic trends.
  - unlisted-: Nuclides that have already been mentioned in the literature but for some reason can no longer be found in the current nuclide tables because their discovery e.g. has not confirmed.

 

Radiation Protection

According to the Radiation Protection Ordinance (StrlSchV 2018, Germany), the following values (columns 1 to 7) apply to the handling of Astatine radionuclides:

NuclideLimit ValueHASS limitSCDaughter NuclidesHalf-life
At-207106 Bq10 Bq/g1.8 h
At-211+107 Bq1000 Bq/g10 Bq cm-27.2 h

(HASS = High-Activity Sealed Radioactive Sources; SC = surface contamination)

 

Literature Sources and References

Properties of the Astatine nucleides

[1] - NuDat: National Nuclear Data Center, Brookhaven National Laboratory, based on ENSDF and the Nuclear Wallet Cards.

[2] - G. Audi et. al.: The NUBASE evaluation of nuclear and decay properties. Nuclear Physics, (2003), DOI 10.1016/j.nuclphysa.2003.11.001.

[3] - Live Chart of Nuclides. Nuclear structure and decay data.

Astatine: NMR properties

[4] - N. J. Stone: Table of nuclear magnetic dipole and electric quadrupole moments. Atomic Data and Nuclear Data Tables, (2005), DOI 10.1016/j.adt.2005.04.001.

[5] - Pekka Pyykkö: Year-2008 nuclear quadrupole moments. Molecular Physics, (2008), DOI 10.1080/00268970802018367.

[6] - Pekka Pyykkö: Year-2017 nuclear quadrupole moments. Molecular Physics, (2018), DOI 10.1080/00268976.2018.1426131.

[7] - N. J. Stone: Table of recommended nuclear magnetic dipole moments. IAEA, (2019).

More sources:

[8] - Isotopic abundances, atomic weights and isotopic masses: see respective keyword.

[9] - G. W. Barton, Jr., A. Ghiorso, I. Perlman:
Radioactivity of Astatine Isotopes.
In: Physical Review, (1951), DOI 10.1103/PhysRev.82.13.

[10] - L.M. Cobb et al.:
Toxicity of Astatine-211 in the Mouse.
In: Human and Experimental Toxicology, (1988), DOI 10.1177/096032718800700602.

[11] - Michael J. Willhauck et al.:
The potential of 211Astatine for NIS-mediated radionuclide therapy in prostate cancer.
In: European Journal of Nuclear Medicine and Molecular Imaging, (2008), DOI 10.1007/s00259-008-0775-4.

[12] - David Leimbach, Julia Karls, Yangyang Guo et al.:
The electron affinity of astatine.
In: Nature Communications, (2020), DOI 10.5281/zenodo.3924371.

 


Category: Isotopes

Last update: 05.07.2020



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