砈的同位素

砈有從191At到223At共33個已知的同位素，都具有放射性。砹最穩定的同位素是半衰期8.1小時的210At，而如果只看存在於天然衰變鏈的同位素，那麼砹最穩定的同位素就是半衰期56秒的219At。

**圖表**
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
α
189Bi
(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
α
190Bi
3+#
β+ （不常見）
194Po
194mAt
480(190) keV
~250 ms
α
190Bi
10−#
IT （不常見）
194At
195At
85
110
194.996268(10)
328(20) ms
α (75%)
191Bi
(1/2+)
β+ (25%)
195Po
195mAt
34(7) keV
147(5) ms
9/2−#
196At
85
111
195.99579(6)
253(9) ms
α (96%)
192Bi
3+#
β+ (4.0%)
196Po
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
α (96%)
193Bi
(9/2−)
β+ (4.0%)
197Po
197mAt
52(10) keV
2.0(2) s
(1/2+)
198At
85
113
197.99284(5)
4.2(3) s
α (94%)
194Bi
(3+)
β+ (6%)
198Po
198mAt
330(90)# keV
1.0(2) s
(10−)
199At
85
114
198.99053(5)
6.92(13) s
α (89%)
195Bi
(9/2−)
β+ (11%)
199Po
200At
85
115
199.990351(26)
43.2(9) s
α (57%)
196Bi
(3+)
β+ (43%)
200Po
200m1At
112.7(30) keV
47(1) s
α (43%)
196Bi
(7+)
IT
200At
β+
200Po
200m2At
344(3) keV
3.5(2) s
(10−)
201At
85
116
200.988417(9)
85(3) s
α (71%)
197Bi
(9/2−)
β+ (29%)
201Po
202At
85
117
201.98863(3)
184(1) s
β+ (88%)
202Po
(2,3)+
α (12%)
198Bi
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
β+ (69%)
203Po
9/2−
α (31%)
199Bi
204At
85
119
203.987251(26)
9.2(2) min
β+ (96%)
204Po
7+
α (3.8%)
200Bi
204mAt
587.30(20) keV
108(10) ms
IT
204At
(10−)
205At
85
120
204.986074(16)
26.2(5) min
β+ (90%)
205Po
9/2−
α (10%)
201Bi
205mAt
2339.65(23) keV
7.76(14) µs
29/2+
206At
85
121
205.986667(22)
30.6(13) min
β+ (99.11%)
206Po
(5)+
α (0.9%)
202Bi
206mAt
807(3) keV
410(80) ns
(10)−
207At
85
122
206.985784(23)
1.80(4) h
β+ (91%)
207Po
9/2−
α (8.6%)
203Bi
208At
85
123
207.986590(28)
1.63(3) h
β+ (99.5%)
208Po
6+
α (0.55%)
204Bi
209At
85
124
208.986173(8)
5.41(5) h
β+ (96%)
209Po
9/2−
α (4.0%)
205Bi
210At
85
125
209.987148(8)
8.1(4) h
β+ (99.8%)
210Po
(5)+
α (0.18%)
206Bi
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
EC (58.2%)
211Po
9/2−
α (42%)
207Bi
212At
85
127
211.990745(8)
0.314(2) s
α (99.95%)
208Bi
(1−)
β+ (0.05%)
212Po
β- (2×10−6%)
212Rn
212m1At
223(7) keV
0.119(3) s
α (99%)
208Bi
(9−)
IT (1%)
212At
212m2At
4771.6(11) keV
152(5) µs
(25−)
213At
85
128
212.992937(5)
125(6) ns
α
209Bi
9/2−
214At
85
129
213.996372(5)
558(10) ns
α
210Bi
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
α
211Bi
9/2−
痕量
216At
85
131
216.002423(4)
0.30(3) ms
α (99.99%)
212Bi
1−
β- (.006%)
216Rn
EC (3×10−7%)
216Po
216mAt
413(5) keV
100# µs
(9−)
217At
85
132
217.004719(5)
32.3(4) ms
α (99.98%)
213Bi
9/2−
痕量
β- (.012%)
217Rn
218At
85
133
218.008694(12)
1.27(6) s
α (99.9%)
214Bi
1−#
痕量
β- (0.10%)
218Rn
219At
85
134
219.011162(4)
56(3) s
α (97%)
215Bi
(9/2−)
痕量
β- (3.0%)
219Rn
220At
85
135
220.01541(6)
3.71(4) min
β- (92%)
220Rn
3(−#)
α (8.0%)
216Bi
221At
85
136
221.01805(21)#
2.3(2) min
β-
221Rn
3/2−#
222At
85
137
222.02233(32)#
54(10) s
β-
222Rn
223At
85
138
223.02519(43)#
50(7) s
3/2−#
備註：畫上#號的數據代表沒有經過實驗的證明，只是理論推測而已，而用括號括起來的代表數據不確定性。

**註釋**

**參考文獻**
 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).- 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 date=20110716114059 , Nuc. Phys. A 729, pp. 3-128 (2003).
** National Nuclear Data Center, Brookhaven National Laboratory. Information extracted from the  NuDat 2.1 database date=20180714022824  (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.