Ruthenium-90

Properties and data of the isotope ⁹⁰Ru.

Content

General data

Name of the isotope:Ruthenium-90; Ru-90Symbol:⁹⁰Ru or 9044RuMass number A:90 (= number of nucleons)Atomic number Z:44 (= number of protons)Neutrons N:46Isotopic mass:89.930344(4) u (atomic weight of Ruthenium-90)Nuclide mass:89.9062077 u (calculated nuclear mass without electrons)Mass excess:-64.88415 MeVMass defect:0.81254354400001 u (per nucleus)Nuclear binding energy:756.87943597 MeV (per nucleus)
8.40977151 MeV (average binding energy per nucleon)Separation energy:S_N = 14.69(30) MeV (first neutron)
S_P = 4.778(5) MeV (first proton)Half-life:11(3) sDecay constant λ:0.063013380050904 s^-1Specific activity α:4.263769109295 × 10⁺²⁰ Bq g^-1
11523700295.392 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Mirror nucleus:Palladium-90Year of discovery:1991

Radioactive Decay

Half-life T_½ = 11(3) s respectively 1.1 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EE/β⁺	⁹⁰Tc	100 %	5.841(4) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 46) and isobaric (same nucleon number A = 90) with Ruthenium-90. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 46	Isobar A = 90
25	⁷¹Mn
26	⁷²Fe
27	⁷³Co
28	⁷⁴Ni
29	⁷⁵Cu
30	⁷⁶Zn
31	⁷⁷Ga
32	⁷⁸Ge	⁹⁰Ge
33	⁷⁹As	⁹⁰As
34	⁸⁰Se	⁹⁰Se
35	⁸¹Br	⁹⁰Br
36	⁸²Kr	⁹⁰Kr
37	⁸³Rb	⁹⁰Rb
38	⁸⁴Sr	⁹⁰Sr
39	⁸⁵Y	⁹⁰Y
40	⁸⁶Zr	⁹⁰Zr
41	⁸⁷Nb	⁹⁰Nb
42	⁸⁸Mo	⁹⁰Mo
43	⁸⁹Tc	⁹⁰Tc
44	⁹⁰Ru	⁹⁰Ru
45	⁹¹Rh	⁹⁰Rh
46	⁹²Pd	⁹⁰Pd
47	⁹³Ag
48	⁹⁴Cd