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Isotopes of astatine



Astatine (At) has 33 known isotopes, all of which are radioactive; the range of their mass numbers is from 191 to 223. There exist also 23 metastable excited states. The longest-lived isotope is 210At, which has a half-life of 8.3 hours; the shortest-lived known isotope is 213At, which has a half-life of 125 nanoseconds.

Additional recommended knowledge

Contents

Older nomenclature

Astatine has also been named:

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
191At 85 106 1.7(+11-5) ms (1/2+)
191mAt 2.1(+4-3) ms (7/2-)
193At 85 108 192.99984(6) 28(+5-4) ms (1/2+)
193m1At 50 keV 21(5) ms (7/2-)
193m2At 39 keV 27(+4-5) ms (13/2+)
194At 85 109 193.99873(20) ~40 ms 3+#
194mAt 480(190) keV ~250 ms 10-#
195At 85 110 194.996268(10) 328(20) ms (1/2+)
195mAt 34(7) keV 147(5) ms 9/2-#
196At 85 111 195.99579(6) 253(9) ms 3+#
196m1At -30(80) keV 20# ms 10-#
196m2At 157.9(1) keV 11 µs 5+#
197At 85 112 196.99319(5) 0.390(16) s (9/2-)
197mAt 52(10) keV 2.0(2) s (1/2+)
198At 85 113 197.99284(5) 4.2(3) s (3+)
198mAt 330(90)# keV 1.0(2) s (10-)
199At 85 114 198.99053(5) 6.92(13) s (9/2-)
200At 85 115 199.990351(26) 43.2(9) s (3+)
200m1At 112.7(30) keV 47(1) s (7+)
200m2At 344(3) keV 3.5(2) s (10-)
201At 85 116 200.988417(9) 85(3) s (9/2-)
202At 85 117 201.98863(3) 184(1) s (2,3)+
202m1At 190(40) keV 182(2) s (7+)
202m2At 580(40) keV 460(50) ms (10-)
203At 85 118 202.986942(13) 7.37(13) min 9/2-
204At 85 119 203.987251(26) 9.2(2) min 7+
204mAt 587.30(20) keV 108(10) ms (10-)
205At 85 120 204.986074(16) 26.2(5) min 9/2-
205mAt 2339.65(23) keV 7.76(14) µs 29/2+
206At 85 121 205.986667(22) 30.6(13) min (5)+
206mAt 807(3) keV 410(80) ns (10)-
207At 85 122 206.985784(23) 1.80(4) h 9/2-
208At 85 123 207.986590(28) 1.63(3) h 6+
209At 85 124 208.986173(8) 5.41(5) h 9/2-
210At 85 125 209.987148(8) 8.1(4) h (5)+
210m1At 2549.6(2) keV 482(6) µs (15)-
210m2At 4027.7(2) keV 5.66(7) µs (19)+
211At 85 126 210.9874963(30) 7.214(7) h 9/2-
212At 85 127 211.990745(8) 0.314(2) s (1-)
212m1At 223(7) keV 0.119(3) s (9-)
212m2At 4771.6(11) keV 152(5) µs (25-)
213At 85 128 212.992937(5) 125(6) ns 9/2-
214At 85 129 213.996372(5) 558(10) ns 1-
214m1At 59(9) keV 265(30) ns
214m2At 231(6) keV 760(15) ns 9-
215At 85 130 214.998653(7) 0.10(2) ms 9/2-
216At 85 131 216.002423(4) 0.30(3) ms 1-
216mAt 413(5) keV 100# µs (9-)
217At 85 132 217.004719(5) 32.3(4) ms 9/2-
218At 85 133 218.008694(12) 1.5(3) s 1-#
219At 85 134 219.011162(4) 56(3) s 5/2-#
220At 85 135 220.01541(6) 3.71(4) min 3(-#)
221At 85 136 221.01805(21)# 2.3(2) min 3/2-#
222At 85 137 222.02233(32)# 54(10) s
223At 85 138 223.02519(43)# 50(7) s 3/2-#

Notes

  • 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.


Isotopes of polonium Isotopes of astatine Isotopes of radon
Index to isotope pages
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Isotopes_of_astatine". A list of authors is available in Wikipedia.
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