Selenium-79

Properties and data of the isotope ⁷⁹Se.

Content

General data

Name of the isotope:Selenium-79; Se-79Symbol:⁷⁹Se or 7934SeMass number A:79 (= number of nucleons)Atomic number Z:34 (= number of protons)Neutrons N:45Isotopic mass:78.91849925(24) u (atomic weight of Selenium-79)Nuclide mass:78.8998482 u (calculated nuclear mass without electrons)Mass excess:-75.91746 MeVMass defect:0.73747305800001 u (per nucleus)Nuclear binding energy:686.95172869 MeV (per nucleus)
8.6955915 MeV (average binding energy per nucleon)Separation energy:S_N = 6.96283(13) MeV (first neutron)
S_P = 10.389(10) MeV (first proton)Half-life:3.27(28) × 10⁵ aDecay constant λ:6.721577116967 × 10^-14 s^-1Specific activity α:518952361.52959 Bq g^-1
0.0140257395008 Ci g^-1Spin and parity:
(nuclear angular momentum)7/2+Magnetic dipole moment:μ(μ_N) = - 1.018(15)Quadrupole moment Q:+ 0.80(2) barn (100 fm²)Nuclear g-factor:g_l = -0.29085714285714Year of discovery:1950

Radioactive Decay

Half-life T_½ = 3.27(28) × 10⁵ a respectively 1.031227 × 10¹³ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	⁷⁹Br	100 %	0.1506(10) MeV

Parent Nuclides

Direct parent isotope is: ⁷⁹As.

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
^79mSe	95.77(3) keV	3.92(1) min	1/2-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 45) and isobaric (same nucleon number A = 79) with Selenium-79. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 45	Isobar A = 79
25	⁷⁰Mn
26	⁷¹Fe
27	⁷²Co
28	⁷³Ni	⁷⁹Ni
29	⁷⁴Cu	⁷⁹Cu
30	⁷⁵Zn	⁷⁹Zn
31	⁷⁶Ga	⁷⁹Ga
32	⁷⁷Ge	⁷⁹Ge
33	⁷⁸As	⁷⁹As
34	⁷⁹Se	⁷⁹Se
35	⁸⁰Br	⁷⁹Br
36	⁸¹Kr	⁷⁹Kr
37	⁸²Rb	⁷⁹Rb
38	⁸³Sr	⁷⁹Sr
39	⁸⁴Y	⁷⁹Y
40	⁸⁵Zr	⁷⁹Zr
41	⁸⁶Nb
42	⁸⁷Mo
43	⁸⁸Tc
44	⁸⁹Ru
45	⁹⁰Rh
46	⁹¹Pd
47	⁹²Ag