Selenium-77
Properties and data of the isotope 77Se.
See also: list of Selenium isotopes.
General data
Name of the isotope:Selenium-77; Se-77Symbol:77Se or 7734SeMass number A:77 (= number of nucleons)Atomic number Z:34 (= number of protons)Neutrons N:43Isotopic mass:76.9199142(5) u (atomic weight of Selenium-77)Nuclide mass:76.9012631 u (calculated nuclear mass without electrons)Mass excess:-74.59944 MeVMass defect:0.71872827600001 u (per nucleus)Nuclear binding energy:669.49107672 MeV (per nucleus)
8.69468931 MeV (average binding energy per nucleon)Separation energy:SN = 7.41886(6) MeV (first neutron)
SP = 9.5971(9) MeV (first proton)Half-life:stableSpin and parity:
(nuclear angular momentum)1/2-Magnetic dipole moment:μ(μN) = +0.53356(5)Charge radius:4.1395(18) femtometer fmYear of discovery:1922
Parent Nuclides
Direct parent isotopes are: 77Br, 77As.
Occurrence
Comparison of the natural Selenium isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):
| | Atomic Mass ma | Quantity | Half-life | Spin |
|---|
Selenium
Isotopic mixture | 78.971 u | 100 % | | |
| Isotope 74Se | 73.9224759(1) u | 0.86(3) % | stable | 0+ |
| Isotope 76Se | 75.9192137(2) u | 9.23(7) % | stable | 0+ |
| Isotope 77Se | 76.9199142(5) u | 7.60(7) % | stable | 1/2- |
| Isotope 78Se | 77.917309(2) u | 23.69(22) % | stable | 0+ |
| Isotope 80Se | 79.916522(8) u | 49.80(36) % | stable | 0+ |
| Isotope 82Se | 81.916700(9) u | 8.82(15) % | 9.39(17) × 1019 a | 0+ |
