Selenium-77m

Properties and data of the isotope ^77mSe.

Contents

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

General data

Name of the isotope:Selenium-77m; Se-77mSymbol:^77mSe or 77m34SeMass number A:77 (= number of nucleons)Atomic number Z:34 (= number of protons)Neutrons N:43Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.2647058823529 (= neutron-proton ratio)Neutron excess (N-Z):9Excitation energy:161.9223(10) keVIsotopic mass:76.9199142(5) u (atomic weight of Selenium-77m)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)Half-life:17.36(5) sDecay constant λ:0.039927832981564 s^-1Specific activity α:3.163829400618 × 10⁺²⁰ Bq g^-1
8550890271.9419 Ci g^-1Spin and parity:
(nuclear angular momentum)7/2+

Radioactive Decay

Half-life T_½ = 17.36(5) s respectively 1.736 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	⁷⁷Se	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
⁷⁷Se		stable	1/2-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 43) and isobaric (same nucleon number A = 77) with Selenium-77m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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