Isotopes of bismuth

Bismuth (₈₃Bi) has 41 known isotopes, ranging from ¹⁸⁴Bi to ²²⁴Bi. Bismuth has no stable isotopes, but does have one naturally occurring, very long-lived isotope; thus, the standard atomic weight can be given from that isotope, bismuth-209. Though it is now known to be radioactive, it may still been considered practically stable because it has a half-life of 2.01×10¹⁹ years, which is more than a billion times the age of the universe.

Isotopes of bismuth (₈₃Bi)

Main isotopes[1] Decay Isotope abun­dance half-life (t1/2) mode pro­duct 207Bi synth 31.22 y β+ 207Pb 208Bi synth 3.68×105 y β+ 208Pb 209Bi 100% 2.01×1019 y α 205Tl 210Bi trace 5.012 d β− 210Po α 206Tl 210mBi synth 3.04×106 y α 206Tl
Standard atomic weight Ar°(Bi)
	208.98040±0.00001[2] 208.98±0.01 (abridged)[3]

Besides ²⁰⁹Bi, the most stable bismuth radioisotopes are ^210mBi with a half-life of 3.04 million years, ²⁰⁸Bi with a half-life of 368,000 years and ²⁰⁷Bi, with a half-life of 31.22 years, none of which occur in nature. All other isotopes have half-lives under 15 days, most under two hours. Of naturally occurring radioisotopes, the most stable is radiogenic ²¹⁰Bi with a half-life of 5.012 days. ^210mBi is unusual for being a nuclear isomer with a half-life many orders of magnitude longer than that of the ground state.

List of isotopes

Nuclide [n 1]	Historic name	Z	N	Isotopic mass (Da)[4] [n 2][n 3]	Half-life[1] [n 4]	Decay mode[1] [n 5]	Daughter isotope [n 6]	Spin and parity[1] [n 7][n 8]	Isotopic abundance
		Excitation energy[n 8]
184Bi[5]		83	101	184.00135(13)#	6.6(15) ms	α	180Tl	3+#
184mBi[n 9]		150(100)# keV			13(2) ms	α	180Tl	10−#
185Bi[6]		83	102	184.99760(9)#	2.8+2.3 −1.0 μs	p (92%)	184Pb	(1/2+)
						α (8%)	181Tl
185mBi		70(50)# keV			58(2) μs	IT	185Bi	(7/2−, 9/2−)
186Bi		83	103	185.996623(18)	14.8(7) ms	α (99.99%)	182Tl	(3+)
						β+ (?%)	186Pb
						β+, SF (0.011%)	(various)
186mBi[n 9]		170(100)# keV			9.8(4) ms	α (99.99%)	182Tl	(10−)
						β+ (?%)	186Pb
						β+, SF (0.011%)	(various)
187Bi		83	104	186.993147(11)	37(2) ms	α	183Tl	(9/2−)
187m1Bi		108(8) keV			370(20) μs	α	183Tl	1/2+
187m2Bi		252(3) keV			7(5) μs	IT	187Bi	(13/2+)
188Bi		83	105	187.992276(12)	60(3) ms	α	184Tl	(3+)
						β+, SF (0.0014%)	(various)
188m1Bi		66(30) keV			>5 μs			7+#
188m2Bi		153(30) keV			265(15) ms	α	184Tl	(10−)
						β+, SF (0.0046%)	(various)
189Bi		83	106	188.989195(22)	688(5) ms	α	185Tl	9/2−
189m1Bi		184(5) keV			5.0(1) ms	α (83%)	185Tl	1/2+
						IT (17%)	189Bi
189m2Bi		357.6(5) keV			880(50) ns	IT	189Bi	13/2+
190Bi		83	107	189.988625(23)	6.3(1) s	α (77%)	186Tl	(3+)
						β+ (23%)	190Pb
						β+, SF (6×10−6%)	(various)
190m1Bi		120(40) keV			6.2(1) s	α (70%)	186Tl	10−
						β+ (30%)	190Pb
						β+, SF (4×10−6%)	(various)
190m2Bi		121(15) keV			175(8) ns	IT	190Bi	(5−)
190m3Bi		394(40) keV			1.3(8) μs	IT	190Bi	(8−)
191Bi		83	108	190.985787(8)	12.4(3) s	α (51%)	187Tl	9/2−
						β+ (49%)	191Pb
191m1Bi		242(4) keV			125(8) ms	α (68%)	187Tl	1/2+
						IT (?%)	191Bi
						β+ (?%)	191Pb
191m2Bi		429.7(5) keV			562(10) ns	IT	191Bi	13/2+
191m3Bi		1875(25)# keV			400(40) ns	IT	191Bi	25/2-#
192Bi		83	109	191.98547(3)	34.6(9) s	β+ (88%)	192Pb	(3+)
						α (12%)	188Tl
192mBi		140(30) keV			39.6(4) s	β+ (90%)	192Pb	10−
						α (10%)	188Tl
193Bi		83	110	192.982947(8)	63.6(30) s	β+ (96.5%)	193Pb	9/2−
						α (3.5%)	189Tl
193m1Bi		305(6) keV			3.20(14) s	α (84%)	189Tl	1/2+
						β+ (16%)	193Pb
193m2Bi		605.53(18) keV			153(10) ns	IT	193Bi	13/2+
193m3Bi		2349.6(6) keV			85(3) μs	IT	193Bi	29/2+
193m4Bi		2405.1(7) keV			3.02(8) μs	IT	193Bi	(29/2−)
194Bi		83	111	193.982799(6)	95(3) s	β+ (99.54%)	194Pb	3+
						α (0.46%)	190Tl
194m1Bi		150(50) keV			125(2) s	β+	194Pb	(6+, 7+)
194m2Bi		163(4) keV			115(4) s	β+ (99.80%)	194Pb	(10−)
						α (0.20%)	190Tl
195Bi		83	112	194.980649(6)	183(4) s	β+ (99.97%)	195Pb	9/2−
						α (0.030%)	191Tl
195m1Bi		399(6) keV			87(1) s	β+ (67%)	195Pb	1/2+
						α (33%)	191Tl
195m2Bi		2381.0(5) keV			614(5) ns	IT	195Bi	(29/2−)
195m3Bi		2615.9(5) keV			1.49(1) μs	IT	195Bi	29/2+
196Bi		83	113	195.980667(26)	5.13(20) min	β+	196Pb	(3+)
						α (0.00115%)	192Tl
196m1Bi		166.4(29) keV			0.6(5) s	IT	196Bi	(7+)
196m2Bi		272(3) keV			4.00(5) min	β+ (74.2%)	196Pb	(10−)
						IT (25.8%)	196Bi
						α (3.8×10−4%)	196Bi
197Bi		83	114	196.978865(9)	9.33(50) min	β+	197Pb	9/2−
197m1Bi		533(12) keV			5.04(16) min	α (55%)	193Tl	1/2+
						β+ (45%)	197Pb
197m2Bi		2403(12) keV			263(13) ns	IT	197Bi	(29/2−)
197m3Bi		2929.5(5) keV			209(30) ns	IT	197Bi	(31/2−)
198Bi		83	115	197.979201(30)	10.3(3) min	β+	198Pb	3+
198m1Bi		290(40) keV			11.6(3) min	β+	198Pb	7+
198m2Bi		540(40) keV			7.7(5) s	IT	198Bi	10−
199Bi		83	116	198.977673(11)	27(1) min	β+	199Pb	9/2−
199m1Bi		667(3) keV			24.70(15) min	β+ (>98%)	199Pb	(1/2+)
						IT (<2%)	199Bi
						α (0.01%)	195Tl
199m2Bi		1962(23) keV			0.10(3) μs	IT	199Bi	25/2+#
199m3Bi		2548(23) keV			168(13) ns	IT	199Bi	29/2−#
200Bi		83	117	199.978131(24)	36.4(5) min	β+	200Pb	7+
200m1Bi[n 9]		100(70)# keV			31(2) min	β+ (?%)	200Pb	(2+)
						IT (?%)	200Bi
200m2Bi		428.20(10) keV			400(50) ms	IT	200Bi	(10−)
201Bi		83	118	200.976995(13)	103(3) min	β+	201Pb	9/2−
201m1Bi		846.35(18) keV			57.5(21) min	β+	201Pb	1/2+
						α (?%)	197Tl
201m2Bi		1973(23) keV			118(28) ns	IT	201Bi	25/2+#
201m3Bi		2012(23) keV			105(75) ns	IT	201Bi	27/2+#
201m4Bi		2781(23) keV			124(4) ns	IT	201Bi	29/2−#
202Bi		83	119	201.977723(15)	1.72(5) h	β+	202Pb	5+
						α (<10−5%)	198Tl
202m1Bi		625(12) keV			3.04(6) μs	IT	202Bi	10−#
202m2Bi		2617(12) keV			310(50) ns	IT	202Bi	(17+)
203Bi		83	120	202.976892(14)	11.76(5) h	β+	203Pb	9/2−
203m1Bi		1098.21(9) keV			305(5) ms	IT	203Bi	1/2+
203m2Bi		2041.5(6) keV			194(30) ns	IT	203Bi	25/2+
204Bi		83	121	203.977836(10)	11.22(10) h	β+	204Pb	6+
204m1Bi		805.5(3) keV			13.0(1) ms	IT	204Bi	10−
204m2Bi		2833.4(11) keV			1.07(3) ms	IT	204Bi	17+
205Bi		83	122	204.977385(5)	14.91(7) d	β+	205Pb	9/2−
205m1Bi		1497.17(9) keV			7.9(7) μs	IT	205Bi	1/2+
205m2Bi		2064.7(4) keV			100(6) ns	IT	205Bi	21/2+
205m3Bi		2139.0(7) keV			220(25) ns	IT	205Bi	25/2+
206Bi		83	123	205.978499(8)	6.243(3) d	β+	206Pb	6+
206m1Bi		59.897(17) keV			7.7(2) μs	IT	206Bi	4+
206m2Bi		1044.8(7) keV			890(10) μs	IT	206Bi	10−
206m3Bi		9233.3(8) keV			155(15) ns	IT	206Bi	(28−)
206m4Bi		10170.5(8) keV			>2 μs	IT	206Bi	(31+)
207Bi		83	124	206.9784706(26)	31.22(17) y	β+	207Pb	9/2−
207mBi		2101.61(16) keV			182(6) μs	IT	207Bi	21/2+
208Bi		83	125	207.9797421(25)	3.68(4)×105 y	β+	208Pb	5+
208mBi		1571.1(4) keV			2.58(4) ms	IT	208Bi	10−
209Bi [n 10][n 11]		83	126	208.9803986(15)	2.01(8)×1019 y [n 12]	α	205Tl	9/2−	1.0000
210Bi	Radium E	83	127	209.9841202(15)	5.012(5) d	β−	210Po	1−	Trace[n 13]
						α (1.32×10−4%)	206Tl
210mBi		271.31(11) keV			3.04(6)×106 y	α[n 14]	206Tl	9−
211Bi	Actinium C	83	128	210.987269(6)	2.14(2) min	α (99.72%)	207Tl	9/2−	Trace[n 15]
						β− (0.276%)	211Po
211mBi		1257(10) keV			1.4(3) μs	IT	211Bi	(25/2−)
212Bi	Thorium C	83	129	211.9912850(20)	60.55(6) min	β− (64.05%)	212Po	1−	Trace[n 16]
						α (35.94%)	208Tl
						β−, α (0.014%)	208Pb
212m1Bi		250(30) keV			25.0(2) min	α (67%)	208Tl	(8−, 9−)
						β−, α (30%)	208Pb
						β− (3%)	212Po
212m2Bi		1479(30) keV			7.0(3) min	β−	212Po	(18−)
213Bi [n 17]		83	130	212.994384(5)	45.60(4) min	β− (97.91%)	213Po	9/2−	Trace[n 18]
						α (2.09%)	209Tl
213mBi		1353(21) keV			>168 s			25/2−#
214Bi	Radium C	83	131	213.998711(12)	19.9(4) min	β− (99.98%)	214Po	1−	Trace[n 13]
						α (0.021%)	210Tl
						β−, α (0.003%)	210Pb
214mBi		539(30) keV			>93 s			8−#
215Bi		83	132	215.001749(6)	7.62(13) min	β−[n 19]	215Po	(9/2−)	Trace[n 15]
215mBi		1367(20)# keV			36.9(6) s	IT (76.9%)	215Bi	(25/2−)
						β− (23.1%)	215Po
216Bi		83	133	216.006306(12)	2.21(4) min	β−	216Po	(6−, 7−)
216mBi[n 9]		24(19) keV			6.6(21) min	β−	216Po	3−#
217Bi		83	134	217.009372(19)	98.5(13) s	β−	217Po	9/2−#
217mBi		1491(20) keV			3.0(2) μs	IT	217Bi	25/2−#
218Bi		83	135	218.014188(29)	33(1) s	β−	218Po	8−#
219Bi		83	136	219.01752(22)#	8.7(29) s	β−	219Po	9/2−#
220Bi		83	137	220.02250(32)#	9.5(57) s	β−	220Po	1−#
221Bi		83	138	221.02598(32)#	2# s [>300 ns]			9/2−#
222Bi		83	139	222.03108(32)#	3# s [>300 ns]			1−#
223Bi		83	140	223.03461(43)#	1# s [>300 ns]			9/2−#
224Bi		83	141	224.03980(43)#	1# s [>300 ns]			1−#
This table header & footer:

1. ^mBi – Excited nuclear isomer.
2. ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
3. # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
4. Bold half-life – nearly stable, half-life longer than age of universe.
5. Modes of decay:

   EC:	Electron capture
   IT:	Isomeric transition
   p:	Proton emission

6. Bold symbol as daughter – Daughter product is stable.
7. ( ) spin value – Indicates spin with weak assignment arguments.
8. # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
9. Order of ground state and isomer is uncertain.
10. Formerly believed to be final decay product of 4n+1 decay chain
11. Primordial radioisotope, also some is radiogenic from the extinct nuclide ²³⁷Np
12. Formerly believed to be the heaviest stable nuclide
13. Intermediate decay product of ²³⁸U
14. Theoretically capable of isomeric transition to ²¹⁰Bi with a partial half-life of ~5.5×10²⁰ years or β⁻ decay to ²¹⁰Po with a partial half-life over 10¹³ years.^[7]
15. Intermediate decay product of ²³⁵U
16. Intermediate decay product of ²³²Th
17. Used in medicine such as for cancer treatment.
18. Intermediate decay product of ²³⁷Np
19. Theoretically capable of α decay to ²¹¹Tl; the branching ratio is expected to be ~8×10⁻⁵% (partial half-life ~18.1 y).^[8]

Bismuth-213

Bismuth-213 (²¹³Bi) has a half-life of 45.6 minutes and decays mainly by beta emission to polonium-213; with only 2.1% going via alpha emission to thallium-209; however, as the polonium instantly decays by alpha, one alpha particle is emitted per atom. The amounts needed for medical use are always produced through its decay chain (the neptunium series) from either thorium-229 (limited supply due to the long life of that isotope) or actinium-225, which can be produced directly from radium-226, for example by bombardment with bremsstrahlung photons from a linear particle accelerator, knocking out a neutron and through beta decay giving actinium-225.

In 1997, an antibody conjugate with ²¹³Bi was used to treat patients with leukemia, and this isotope has otherwise been used in targeted alpha therapy (TAT) to treat a variety of cancers.^[9]

Bismuth-213 is also produced in the decay of uranium-233, the fuel bred by thorium reactors, but as mentioned this goes through the long-lived thorium-229, so the production rates from each reactor will not be large.

See also

Daughter products other than bismuth

• Isotopes of polonium
• Isotopes of lead
• Isotopes of thallium

References

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: Bismuth". CIAAW. 2005.
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.
4. 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.
5. Andreyev, A. N.; Ackermann, D.; Heßberger, F. P.; Hofmann, S.; Huyse, M.; Kojouharov, I.; Kindler, B.; Lommel, B.; Münzenberg, G.; Page, R. D.; Vel, K. Van de; Duppen, P. Van; Heyde, K. (1 October 2003). "α-decay spectroscopy of light odd-odd Bi isotopes - II: ¹⁸⁶Bi and the new nuclide ¹⁸⁴Bi" (PDF). The European Physical Journal A. 18 (1): 55–64. Bibcode:2003EPJA...18...55A. doi:10.1140/epja/i2003-10051-1. ISSN 1434-601X. S2CID 122369569. Retrieved 20 June 2023.
6. Doherty, D. T.; Andreyev, A. N.; Seweryniak, D.; Woods, P. J.; Carpenter, M. P.; Auranen, K.; Ayangeakaa, A. D.; Back, B. B.; Bottoni, S.; Canete, L.; Cubiss, J. G.; Harker, J.; Haylett, T.; Huang, T.; Janssens, R. V. F.; Jenkins, D. G.; Kondev, F. G.; Lauritsen, T.; Lederer-Woods, C.; Li, J.; Müller-Gatermann, C.; Potterveld, D.; Reviol, W.; Savard, G.; Stolze, S.; Zhu, S. (12 November 2021). "Solving the Puzzles of the Decay of the Heaviest Known Proton-Emitting Nucleus ¹⁸⁵Bi". Physical Review Letters. 127 (20): 202501. Bibcode:2021PhRvL.127t2501D. doi:10.1103/PhysRevLett.127.202501. hdl:20.500.11820/ac1e5604-7bba-4a25-a538-795ca4bdc875. ISSN 0031-9007. PMID 34860042. S2CID 244089059. Retrieved 20 June 2023.
7. Tuggle, D. G. (August 1976). Decay studies of a long lived high spin isomer of ²¹⁰Bi (Thesis). California Univ., Berkeley (USA): Lawrence Berkeley Lab. See the section "^210mBi Decay to ²¹⁰Po".
8. "Adopted Levels for ²¹⁵Bi" (PDF). NNDC Chart of Nuclides.
9. Imam, S (2001). "Advancements in cancer therapy with alpha-emitters: a review". International Journal of Radiation Oncology, Biology, Physics. 51 (1): 271–278. doi:10.1016/S0360-3016(01)01585-1. PMID 11516878.