Gallium-78m

Properties and data of the isotope ⁷⁸Ga.

Content

General data

Name of the isotope:Gallium-78m; Ga-78mSymbol:⁷⁸Ga or 7831GaMass number A:78 (= number of nucleons)Atomic number Z:31 (= number of protons)Neutrons N:47Isotopic mass:77.9316088(20) u (atomic weight of Gallium-78m)
Excitation energy: 559.6(7) keVNuclide mass:77.9146034 u (calculated nuclear mass without electrons)Mass excess:-63.70599 MeVMass defect:0.718218244 u (per nucleus)Nuclear binding energy:669.01598498 MeV (per nucleus)
8.57712801 MeV (average binding energy per nucleon)Half-life:500 nsDecay constant λ:1386294.3611199 s^-1Specific activity α:1.084215573506 × 10⁺²⁸ Bq g^-1
2.930312360828 × 10⁺¹⁷ Ci g^-1Spin and parity:
(nuclear angular momentum)

Radioactive Decay

Half-life T_½ = 500 ns respectively 5.0 × 10^-7 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	⁷⁸Ga	~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
⁷⁸Ga		5.09(5) s	(3+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 47) and isobaric (same nucleon number A = 78) with Gallium-78m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 47	Isobar A = 78
26	⁷³Fe
27	⁷⁴Co
28	⁷⁵Ni	⁷⁸Ni
29	⁷⁶Cu	⁷⁸Cu
30	⁷⁷Zn	⁷⁸Zn
31	⁷⁸Ga	⁷⁸Ga
32	⁷⁹Ge	⁷⁸Ge
33	⁸⁰As	⁷⁸As
34	⁸¹Se	⁷⁸Se
35	⁸²Br	⁷⁸Br
36	⁸³Kr	⁷⁸Kr
37	⁸⁴Rb	⁷⁸Rb
38	⁸⁵Sr	⁷⁸Sr
39	⁸⁶Y	⁷⁸Y
40	⁸⁷Zr	⁷⁸Zr
41	⁸⁸Nb
42	⁸⁹Mo
43	⁹⁰Tc
44	⁹¹Ru
45	⁹²Rh
46	⁹³Pd
47	⁹⁴Ag
48	⁹⁵Cd
49	⁹⁶In