Xenon-109

Properties and data of the isotope ¹⁰⁹Xe.

Content

General data

Name of the isotope:Xenon-109; Xe-109Symbol:¹⁰⁹Xe or 10954XeMass number A:109 (= number of nucleons)Atomic number Z:54 (= number of protons)Neutrons N:55Isotopic mass:108.95043(32) u (atomic weight of Xenon-109)Nuclide mass:108.9208086 u (calculated nuclear mass without electrons)Mass excess:-46.17416 MeVMass defect:0.948692108 u (per nucleus)Nuclear binding energy:883.70100645 MeV (per nucleus)
8.10734868 MeV (average binding energy per nucleon)Separation energy:
S_P = 0.81(33) MeV (first proton)Half-life:13(2) msDecay constant λ:53.319013889227 s^-1Specific activity α:2.973098260683 × 10⁺²³ Bq g^-1
8035400704550.8 Ci g^-1Spin and parity:
(nuclear angular momentum)(7/2+)Year of discovery:2006

Radioactive Decay

Half-life T_½ = 13(2) ms respectively 1.3 × 10^-2 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	¹⁰⁵Te	100 %	4.217(7) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 55) and isobaric (same nucleon number A = 109) with Xenon-109. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 55	Isobar A = 109
30	⁸⁵Zn
31	⁸⁶Ga
32	⁸⁷Ge
33	⁸⁸As
34	⁸⁹Se
35	⁹⁰Br
36	⁹¹Kr
37	⁹²Rb
38	⁹³Sr
39	⁹⁴Y	¹⁰⁹Y
40	⁹⁵Zr	¹⁰⁹Zr
41	⁹⁶Nb	¹⁰⁹Nb
42	⁹⁷Mo	¹⁰⁹Mo
43	⁹⁸Tc	¹⁰⁹Tc
44	⁹⁹Ru	¹⁰⁹Ru
45	¹⁰⁰Rh	¹⁰⁹Rh
46	¹⁰¹Pd	¹⁰⁹Pd
47	¹⁰²Ag	¹⁰⁹Ag
48	¹⁰³Cd	¹⁰⁹Cd
49	¹⁰⁴In	¹⁰⁹In
50	¹⁰⁵Sn	¹⁰⁹Sn
51	¹⁰⁶Sb	¹⁰⁹Sb
52	¹⁰⁷Te	¹⁰⁹Te
53	¹⁰⁸I	¹⁰⁹I
54	¹⁰⁹Xe	¹⁰⁹Xe