Isotopes of bromine

Bromine (Br) has two stable isotopes, ⁷⁹Br and ⁸¹Br, and 30 known unstable isotopes, the most stable of which is ⁷⁷Br with a half-life of 57.036 hours.
Standard atomic mass: 79.904(1) u

Table

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life	decay mode(s)	daughter isotope(s)	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
	excitation energy
66Br	35	31			p	65Se
67Br	35	32	66.96479(54)#		p	66Se	1/2−#
68Br	35	33	67.95852(38)#	<1.2 µs	p	67Se	3+#
69Br	35	34	68.95011(11)#	<24 ns	p	68Se	1/2−#
70Br	35	35	69.94479(33)#	79.1(8) ms	β+	70Se	0+#
70mBr	2292.2(8) keV			2.2(2) s	β+	70Se	(9+)
					IT	70Br
71Br	35	36	70.93874(61)	21.4(6) s	β+	71Se	(5/2)−
72Br	35	37	71.93664(6)	78.6(24) s	β+	72Se	1+
72mBr	100.92(3) keV			10.6(3) s	IT (>99.9%)	72Br	1−
					β+ (<0.1%)	72Se
73Br	35	38	72.93169(5)	3.4(2) min	β+	73Se	1/2−
74Br	35	39	73.929891(16)	25.4(3) min	β+	74Se	(0−)
74mBr	13.58(21) keV			46(2) min	β+	74Se	4(+#)
75Br	35	40	74.925776(15)	96.7(13) min	β+	75Se	3/2−
76Br	35	41	75.924541(10)	16.2(2) h	β+	76Se	1−
76mBr	102.58(3) keV			1.31(2) s	IT (99.4%)	76Br	(4)+
					β+ (0.6%)	76Se
77Br	35	42	76.921379(3)	57.036(6) h	β+	77Se	3/2−
77mBr	105.86(8) keV			4.28(10) min	IT	77Br	9/2+
78Br	35	43	77.921146(4)	6.46(4) min	β+ (99.99%)	78Se	1+
					β− (0.01%)	78Kr
78mBr	180.82(13) keV			119.2(10) µs			(4+)
79Br	35	44	78.9183371(22)	Stable			3/2−	0.5069(7)
79mBr	207.61(9) keV			4.86(4) s	IT	79Br	(9/2+)
80Br	35	45	79.9185293(22)	17.68(2) min	β− (91.7%)	80Kr	1+
					β+ (8.3%)	80Se
80mBr	85.843(4) keV			4.4205(8) h	IT	80Br	5−
81Br	35	46	80.9162906(21)	Stable			3/2−	0.4931(7)
81mBr	536.20(9) keV			34.6(28) µs			9/2+
82Br	35	47	81.9168041(21)	35.282(7) h	β−	82Kr	5−
82mBr	45.9492(10) keV			6.13(5) min	IT	82Br	2−
					β−	82Kr
83Br	35	48	82.915180(5)	2.40(2) h	β−	83Kr	3/2−
83mBr	3068.8(6) keV			700(100) ns			(19/2−)
84Br	35	49	83.916479(16)	31.80(8) min	β−	84Kr	2−
84m1Br	320(10) keV			6.0(2) min	β−	84Kr	6−
84m2Br	408.2(4) keV			<140 ns			1+
85Br	35	50	84.915608(21)	2.90(6) min	β−	85Kr	3/2−
86Br	35	51	85.918798(12)	55.1(4) s	β−	86Kr	(2−)
87Br	35	52	86.920711(19)	55.65(13) s	β− (97.48%)	87Kr	3/2−
					β−, n (2.52%)	86Kr
88Br	35	53	87.92407(4)	16.29(6) s	β− (93.42%)	88Kr	(2−)
					β−, n (6.48%)	87Kr
88mBr	272.7(3) keV			5.4(7) µs
89Br	35	54	88.92639(6)	4.40(3) s	β− (86.2%)	89Kr	(3/2−,5/2−)
					β−, n (13.8%)	88Kr
90Br	35	55	89.93063(8)	1.91(1) s	β− (74.8%)	90Kr
					β−, n (25.2%)	89Kr
91Br	35	56	90.93397(8)	541(5) ms	β− (80%)	91Kr	3/2−#
					β−, n (20%)	90Kr
92Br	35	57	91.93926(5)	0.343(15) s	β− (66.9%)	92Kr	(2−)
					β−, n (33.1%)	91Kr
93Br	35	58	92.94305(32)#	102(10) ms	β− (89%)	93Kr	3/2−#
					β−, n (11%)	92Kr
94Br	35	59	93.94868(43)#	70(20) ms	β− (70%)	94Kr
					β−, n (30%)	93Kr
95Br	35	60	94.95287(54)#	50# ms [>300 ns]			3/2−#
96Br	35	61	95.95853(75)#	20# ms [>300 ns]
97Br	35	62	96.96280(86)#	10# ms [>300 ns]			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:
  • G. Audi, A. H. Wapstra, C. Thibault, J. Blachot and O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear Physics A. 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.{{cite journal}}: CS1 maint: multiple names: authors list (link)
• Isotopic compositions and standard atomic masses from:
  • J. R. de Laeter, J. K. Böhlke, P. De Bièvre, H. Hidaka, H. S. Peiser, K. J. R. Rosman and P. D. P. Taylor (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry. 75 (6): 683–800. doi:10.1351/pac200375060683.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  • M. E. Wieser (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry. 78 (11): 2051–2066. doi:10.1351/pac200678112051. {{cite journal}}: Unknown parameter |laysummary= ignored (help)
• Half-life, spin, and isomer data selected from the following sources. See editing notes on this article's talk page.
  • G. Audi, A. H. Wapstra, C. Thibault, J. Blachot and O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear Physics A. 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  • National Nuclear Data Center. "NuDat 2.1 database". Brookhaven National Laboratory. Retrieved September 2005. {{cite web}}: Check date values in: |accessdate= (help)
  • N. E. Holden (2004). "Table of the Isotopes". In D. R. Lide (ed.). CRC Handbook of Chemistry and Physics (85th ed.). CRC Press. Section 11. ISBN 978-0-8493-0485-9. {{cite book}}: Unknown parameter |nopp= ignored (|no-pp= suggested) (help)