Iodine-111

Properties and data of the isotope ¹¹¹I.

Content

General data

Name of the isotope:Iodine-111; I-111Other names:Jod-111Symbol:¹¹¹I or 11153IMass number A:111 (= number of nucleons)Atomic number Z:53 (= number of protons)Neutrons N:58Isotopic mass:110.930269(5) u (atomic weight of Iodine-111)Nuclide mass:110.9011961 u (calculated nuclear mass without electrons)Mass excess:-64.95401 MeVMass defect:0.98702282400001 u (per nucleus)Nuclear binding energy:919.40583842 MeV (per nucleus)
8.28293548 MeV (average binding energy per nucleon)Separation energy:S_N = 12.56(5) MeV (first neutron)
S_P = 0.013(8) MeV (first proton)Half-life:2.5(2) sDecay constant λ:0.27725887222398 s^-1Specific activity α:1.517901802909 × 10⁺²¹ Bq g^-1
41024373051.597 Ci g^-1Spin and parity:
(nuclear angular momentum)(5/2+)Year of discovery:1977

Radioactive Decay

Half-life T_½ = 2.5(2) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EE/β⁺	¹¹¹Te	99.9 %	8.634(8) MeV
α	¹⁰⁷Sb	0.1 %	3.275(5) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 58) and isobaric (same nucleon number A = 111) with Iodine-111. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 58	Isobar A = 111
32	⁹⁰Ge
33	⁹¹As
34	⁹²Se
35	⁹³Br
36	⁹⁴Kr
37	⁹⁵Rb
38	⁹⁶Sr
39	⁹⁷Y
40	⁹⁸Zr	¹¹¹Zr
41	⁹⁹Nb	¹¹¹Nb
42	¹⁰⁰Mo	¹¹¹Mo
43	¹⁰¹Tc	¹¹¹Tc
44	¹⁰²Ru	¹¹¹Ru
45	¹⁰³Rh	¹¹¹Rh
46	¹⁰⁴Pd	¹¹¹Pd
47	¹⁰⁵Ag	¹¹¹Ag
48	¹⁰⁶Cd	¹¹¹Cd
49	¹⁰⁷In	¹¹¹In
50	¹⁰⁸Sn	¹¹¹Sn
51	¹⁰⁹Sb	¹¹¹Sb
52	¹¹⁰Te	¹¹¹Te
53	¹¹¹I	¹¹¹I
54	¹¹²Xe	¹¹¹Xe
55	¹¹³Cs
56	¹¹⁴Ba