Iodine-109

Properties and data of the isotope ¹⁰⁹I.

Content

General data

Name of the isotope:Iodine-109; I-109Other names:Jod-109Symbol:¹⁰⁹I or 10953IMass number A:109 (= number of nucleons)Atomic number Z:53 (= number of protons)Neutrons N:56Isotopic mass:108.938086(7) u (atomic weight of Iodine-109)Nuclide mass:108.9090131 u (calculated nuclear mass without electrons)Mass excess:-57.67252 MeVMass defect:0.961875992 u (per nucleus)Nuclear binding energy:895.98171529 MeV (per nucleus)
8.22001574 MeV (average binding energy per nucleon)Separation energy:S_N = 13.09(13) MeV (first neutron)Half-life:92.8(8) μsDecay constant λ:7469.2584112063 s^-1Specific activity α:4.164900580699 × 10⁺²⁵ Bq g^-1
1.125648805594 × 10⁺¹⁵ Ci g^-1Spin and parity:
(nuclear angular momentum)(1/2+.3/2+)Year of discovery:1984

Radioactive Decay

Half-life T_½ = 92.8(8) μs respectively 9.28 × 10^-5 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
p	¹⁰⁸Te	99.986(4) %
α	¹⁰⁵Sb	0.014(4) %	3.918(21) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 56) and isobaric (same nucleon number A = 109) with Iodine-109. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 56	Isobar A = 109
31	⁸⁷Ga
32	⁸⁸Ge
33	⁸⁹As
34	⁹⁰Se
35	⁹¹Br
36	⁹²Kr
37	⁹³Rb
38	⁹⁴Sr
39	⁹⁵Y	¹⁰⁹Y
40	⁹⁶Zr	¹⁰⁹Zr
41	⁹⁷Nb	¹⁰⁹Nb
42	⁹⁸Mo	¹⁰⁹Mo
43	⁹⁹Tc	¹⁰⁹Tc
44	¹⁰⁰Ru	¹⁰⁹Ru
45	¹⁰¹Rh	¹⁰⁹Rh
46	¹⁰²Pd	¹⁰⁹Pd
47	¹⁰³Ag	¹⁰⁹Ag
48	¹⁰⁴Cd	¹⁰⁹Cd
49	¹⁰⁵In	¹⁰⁹In
50	¹⁰⁶Sn	¹⁰⁹Sn
51	¹⁰⁷Sb	¹⁰⁹Sb
52	¹⁰⁸Te	¹⁰⁹Te
53	¹⁰⁹I	¹⁰⁹I
54	¹¹⁰Xe	¹⁰⁹Xe