Isotopes of bromine

Bromine (₃₅Br) has two stable isotopes, ⁷⁹Br and ⁸¹Br, and 30 known radioisotopes, the most stable of which is ⁷⁷Br, with a half-life of 57.036 hours.

Main isotopes of bromine (₃₅Br)

Iso­tope Decay abun­dance half-life (t1/2) mode pro­duct ^79Br 51% stable ^81Br 49% stable
Standard atomic weight Ar, standard(Br)	[79.901, 79.907][1] Conventional: 79.904

List of isotopes

Nuclide [n 1]	Z	N	Isotopic mass (Da) [n 2][n 3]	Half-life	Decay mode [n 4]	Daughter isotope [n 5][n 6]	Spin and parity [n 7][n 8]	Natural abundance (mole fraction)
	Excitation energy							Normal proportion	Range of variation
^68Br[2]	35	33	67.95836(28)#	~50 ns	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−#

1. ^mBr – 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. Modes of decay:

   IT:	Isomeric transition
   n:	Neutron emission
   p:	Proton emission

5. Bold italics symbol as daughter – Daughter product is nearly stable.
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).

References

1. Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.
2. Wimmer, K.; et al. (2019). "Discovery of ⁶⁸Br in secondary reactions of radioactive beams". Physics Letters B. 795: 266–270. arXiv:1906.04067. doi:10.1016/j.physletb.2019.06.014.

• Isotope masses from:
  • Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
• Isotopic compositions and standard atomic masses from:
  • de Laeter, John Robert; Böhlke, John Karl; De Bièvre, Paul; Hidaka, Hiroshi; Peiser, H. Steffen; Rosman, Kevin J. R.; Taylor, Philip D. P. (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry. 75 (6): 683–800. doi:10.1351/pac200375060683.
  • Wieser, Michael E. (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry. 78 (11): 2051–2066. doi:10.1351/pac200678112051. Lay summary.
• Half-life, spin, and isomer data selected from the following sources.
  • Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
  • National Nuclear Data Center. "NuDat 2.x database". Brookhaven National Laboratory.
  • Holden, Norman E. (2004). "11. Table of the Isotopes". In Lide, David R. (ed.). CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9.