Bromine-79
Properties and data of the isotope 79Br.
Bromine-79 is a stable isotope of the chemical element bromine, which has 44 neutrons in its atomic nucleus in addition to the element-specific 35 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 79. Br-79 accounts for 50.65% of natural terrestrial bromine deposits.
The first mass spectrometric detection and thus the discovery of bromine-79 was reported in 1920 [1].
See also: List of individual Bromine isotopes (and general data sources).
General data
Name of the isotope:Bromine-79; Br-79Symbol:79Br or 7935BrMass number A:79 (= number of nucleons)Atomic number Z:35 (= number of protons)Neutrons N:44Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.2571428571429 (= neutron-proton ratio)Neutron excess (N-Z):9Isotopic mass:78.9183376(11) u (atomic weight of Bromine-79)Nuclide mass:78.899138 u (calculated nuclear mass without electrons)Mass excess:-76.06804 MeVMass defect:0.736794824 u (per nucleus)Nuclear binding energy:686.31995779 MeV (per nucleus)
8.6875944 MeV (average binding energy per nucleon)Separation energy:SN = 10.687(4) MeV (first neutron)
SP = 6.3311(10) MeV (first proton)Half-life:stableSpin and parity:
(nuclear angular momentum)3/2-Magnetic dipole moment:μ(μN) = +2.1046(6)Charge radius:4.1629(21) femtometer fmYear of discovery:1920
Parent Nuclides
Direct parent isotopes are: 79Kr, 79Se.
Occurrence
Comparison of the natural Bromine isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):
| | Atomic Mass ma | Quantity | Half-life | Spin |
|---|
Bromine
Isotopic mixture | 79.904 u | 100 % | | |
| Isotope 81Br | 80.9162882(10) u | 49.35 %
[49.2 - 49.5 %] | stable | 3/2- |
| Isotope 79Br | 78.9183376(11) u | 50.65 %
[50.5 - 50.8 %] | stable | 3/2- |
NMR data
Nuclear magnetic properties and parameters of the NMR active Nuclide 79Br
Isotope:79Br-NMRQuantity:50.65 % [50.5 - 50.8 %]Spin:3/2-Nuclearmagnetic moment
μ/μN:+2.1046(6)Gyromagnetic ratio γ:6.725616 · 107 rad T-1 s-1
10.70415 MHz T-1Nuclear g-factor:gl = 1.4030666666667Quadrupole moment Q:+0.3087(2) barn (100 fm2)Line width parameter (factor):l = 1270.61 fm4Resonance frequency:v0 = 10.7042 MHz at 1 TRelative Sensitivity:[related to 1H = 1.000]:
0.07945 (H0 = const.)
1.2570 (v0 = const.)
0.0403 (at natural abundance)
relative receptivity as compared to 13C:
237 (at natural abundance)
468 (enriched)Reference compound:
(conditions)0.01 M sodium bromide solution NaBr in deuterium oxide D2O.Frequency ratio:Ξ(79Br) = 25.053980 % [based on the reference substance]Chemical shift range:ca. 600 ppm [-500 to +100]
Nuclear Isomers
Nuclear isomers or excited states with the activation energy in keV related to the ground state.
| Nuclear Isomer | Excitation Energy | Half-life | Spin |
|---|
| 79mBr | 207.61(9) keV | 4.86(4) s | 9/2+ |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 44) and isobaric (same nucleon number A = 79) with Bromine-79. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 44 | Isobar A = 79 |
|---|
| 22 | 66Ti | |
| 23 | 67V | |
| 24 | 68Cr | |
| 25 | 69Mn | |
| 26 | 70Fe | |
| 27 | 71Co | |
| 28 | 72Ni | 79Ni |
| 29 | 73Cu | 79Cu |
| 30 | 74Zn | 79Zn |
| 31 | 75Ga | 79Ga |
| 32 | 76Ge | 79Ge |
| 33 | 77As | 79As |
| 34 | 78Se | 79Se |
| 35 | 79Br | 79Br |
| 36 | 80Kr | 79Kr |
| 37 | 81Rb | 79Rb |
| 38 | 82Sr | 79Sr |
| 39 | 83Y | 79Y |
| 40 | 84Zr | 79Zr |
| 41 | 85Nb | |
| 42 | 86Mo | |
| 43 | 87Tc | |
| 44 | 88Ru | |
| 45 | 89Rh | |
| 46 | 90Pd | |
External data and identifiers
Literature and References
[1] - F. W. Aston:
The Constitution of the Elements.
In: Nature, 105, 547, (1920), DOI 10.1038/105547a0.
Last update: 2026-01-23
Perma link: https://www.chemlin.org/isotope/bromine-79
© 1996 - 2026 ChemLin
