Bromine-78

Properties and data of the isotope ⁷⁸Br.

Contents

See also: List of individual Bromine isotopes (and general data sources).

General data

Name of the isotope:Bromine-78; Br-78Symbol:⁷⁸Br or 7835BrMass number A:78 (= number of nucleons)Atomic number Z:35 (= number of protons)Neutrons N:43Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.2285714285714 (= neutron-proton ratio)Neutron excess (N-Z):8Isotopic mass:77.921146(4) u (atomic weight of Bromine-78)Nuclide mass:77.9019464 u (calculated nuclear mass without electrons)Mass excess:-73.45203 MeVMass defect:0.72532150800001 u (per nucleus)Nuclear binding energy:675.63263277 MeV (per nucleus)
8.66195683 MeV (average binding energy per nucleon)Separation energy:S_N = 8.289(5) MeV (first neutron)
S_P = 6.142(4) MeV (first proton)Half-life:6.45(4) minDecay constant λ:0.001791077985943 s^-1Specific activity α:1.400795314607 × 10⁺¹⁹ Bq g^-1
378593328.27241 Ci g^-1Spin and parity:
(nuclear angular momentum)1+Magnetic dipole moment:μ(μ_N) = 0.13(3)Nuclear g-factor:g_l = 0.13Year of discovery:1937

Radioactive Decay

Half-life T_½ = 6.45(4) min (minutes) respectively 3.87 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	⁷⁸Se	≥ 99.99 %	3.574(4) MeV
β^-	⁷⁸Kr	≤ 0.01 %	0.726(4) MeV

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
^78mBr	180.89(13) keV	119.4(10) μs	(4+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 43) and isobaric (same nucleon number A = 78) with Bromine-78. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 43	Isobar A = 78
22	⁶⁵Ti
23	⁶⁶V
24	⁶⁷Cr
25	⁶⁸Mn
26	⁶⁹Fe
27	⁷⁰Co
28	⁷¹Ni	⁷⁸Ni
29	⁷²Cu	⁷⁸Cu
30	⁷³Zn	⁷⁸Zn
31	⁷⁴Ga	⁷⁸Ga
32	⁷⁵Ge	⁷⁸Ge
33	⁷⁶As	⁷⁸As
34	⁷⁷Se	⁷⁸Se
35	⁷⁸Br	⁷⁸Br
36	⁷⁹Kr	⁷⁸Kr
37	⁸⁰Rb	⁷⁸Rb
38	⁸¹Sr	⁷⁸Sr
39	⁸²Y	⁷⁸Y
40	⁸³Zr	⁷⁸Zr
41	⁸⁴Nb
42	⁸⁵Mo
43	⁸⁶Tc
44	⁸⁷Ru