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.