Ruthenium-91

Properties and data of the isotope ⁹¹Ru.

Content

General data

Name of the isotope:Ruthenium-91; Ru-91Symbol:⁹¹Ru or 9144RuMass number A:91 (= number of nucleons)Atomic number Z:44 (= number of protons)Neutrons N:47Isotopic mass:90.9267415(24) u (atomic weight of Ruthenium-91)Nuclide mass:90.9026052 u (calculated nuclear mass without electrons)Mass excess:-68.23985 MeVMass defect:0.82481095999999 u (per nucleus)Nuclear binding energy:768.30646037 MeV (per nucleus)
8.44292814 MeV (average binding energy per nucleon)Separation energy:S_N = 11.427(4) MeV (first neutron)
S_P = 4.8041(24) MeV (first proton)Half-life:8.0(4) sDecay constant λ:0.086643397569993 s^-1Specific activity α:5.797541608333 × 10⁺²⁰ Bq g^-1
15669031373.874 Ci g^-1Spin and parity:
(nuclear angular momentum)(9/2+)Year of discovery:1983

Radioactive Decay

Half-life T_½ = 8.0(4) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EE/β⁺	⁹¹Tc	100 %	7.747(3) MeV

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
^91mRu	+x keV	7.6(8) s	(1/2-)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 47) and isobaric (same nucleon number A = 91) with Ruthenium-91. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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