Ruthenium-109

Properties and data of the isotope ¹⁰⁹Ru.

Contents

General data

Name of the isotope:Ruthenium-109; Ru-109Symbol:¹⁰⁹Ru or 10944RuMass number A:109 (= number of nucleons)Atomic number Z:44 (= number of protons)Neutrons N:65Isotopic mass:108.913324(10) u (atomic weight of Ruthenium-109)Nuclide mass:108.8891877 u (calculated nuclear mass without electrons)Mass excess:-80.73817 MeVMass defect:0.99419694800001 u (per nucleus)Nuclear binding energy:926.08849188 MeV (per nucleus)
8.4962247 MeV (average binding energy per nucleon)Separation energy:S_N = 5.148(12) MeV (first neutron)
S_P = 12.105(12) MeV (first proton)Half-life:34.4(2) sDecay constant λ:0.020149627341859 s^-1Specific activity α:1.123554575258 × 10⁺²⁰ Bq g^-1
3036633987.1849 Ci g^-1Spin and parity:
(nuclear angular momentum)(5/2+)Year of discovery:1967

Radioactive Decay

Half-life T_½ = 34.4(2) s respectively 3.44 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁰⁹Rh	100 %	4.261(10) MeV

Parent Nuclides

Direct parent isotopes are: ¹⁰⁹Tc, ²⁵²Cf.

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
^109mRu	68.75(12) keV	0.50(12) μs	(1/2+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 65) and isobaric (same nucleon number A = 109) with Ruthenium-109. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 65	Isobar A = 109
36	¹⁰¹Kr
37	¹⁰²Rb
38	¹⁰³Sr
39	¹⁰⁴Y	¹⁰⁹Y
40	¹⁰⁵Zr	¹⁰⁹Zr
41	¹⁰⁶Nb	¹⁰⁹Nb
42	¹⁰⁷Mo	¹⁰⁹Mo
43	¹⁰⁸Tc	¹⁰⁹Tc
44	¹⁰⁹Ru	¹⁰⁹Ru
45	¹¹⁰Rh	¹⁰⁹Rh
46	¹¹¹Pd	¹⁰⁹Pd
47	¹¹²Ag	¹⁰⁹Ag
48	¹¹³Cd	¹⁰⁹Cd
49	¹¹⁴In	¹⁰⁹In
50	¹¹⁵Sn	¹⁰⁹Sn
51	¹¹⁶Sb	¹⁰⁹Sb
52	¹¹⁷Te	¹⁰⁹Te
53	¹¹⁸I	¹⁰⁹I
54	¹¹⁹Xe	¹⁰⁹Xe
55	¹²⁰Cs
56	¹²¹Ba
57	¹²²La
58	¹²³Ce
59	¹²⁴Pr
60	¹²⁵Nd
61	¹²⁶Pm