Selenium-76

Properties and data of the isotope ⁷⁶Se.

Contents

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

General data

Name of the isotope:Selenium-76; Se-76Symbol:⁷⁶Se or 7634SeMass number A:76 (= number of nucleons)Atomic number Z:34 (= number of protons)Neutrons N:42Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.2352941176471 (= neutron-proton ratio)Neutron excess (N-Z):8Isotopic mass:75.9192137(2) u (atomic weight of Selenium-76)Nuclide mass:75.9005626 u (calculated nuclear mass without electrons)Mass excess:-75.25195 MeVMass defect:0.71076386 u (per nucleus)Nuclear binding energy:662.07227101 MeV (per nucleus)
8.71147725 MeV (average binding energy per nucleon)Separation energy:S_N = 11.15379(7) MeV (first neutron)
S_P = 9.5067(9) MeV (first proton)Half-life:stableSpin and parity:
(nuclear angular momentum)0+Charge radius:4.1395(16) femtometer fmYear of discovery:1922

Parent Nuclides

Direct parent isotopes are: ⁷⁶Br, ⁷⁶As.

Occurrence

Comparison of the natural Selenium isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):

	Atomic Mass m_a	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 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+
Isotope ⁷⁷Se	76.91991415(7) u	7.60(7) %	stable	1/2-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 42) and isobaric (same nucleon number A = 76) with Selenium-76. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 42	Isobar A = 76
21	⁶³Sc
22	⁶⁴Ti
23	⁶⁵V
24	⁶⁶Cr
25	⁶⁷Mn
26	⁶⁸Fe
27	⁶⁹Co	⁷⁶Co
28	⁷⁰Ni	⁷⁶Ni
29	⁷¹Cu	⁷⁶Cu
30	⁷²Zn	⁷⁶Zn
31	⁷³Ga	⁷⁶Ga
32	⁷⁴Ge	⁷⁶Ge
33	⁷⁵As	⁷⁶As
34	⁷⁶Se	⁷⁶Se
35	⁷⁷Br	⁷⁶Br
36	⁷⁸Kr	⁷⁶Kr
37	⁷⁹Rb	⁷⁶Rb
38	⁸⁰Sr	⁷⁶Sr
39	⁸¹Y	⁷⁶Y
40	⁸²Zr
41	⁸³Nb
42	⁸⁴Mo
43	⁸⁵Tc
44	⁸⁶Ru