Iodine-128m2

Properties and data of the isotope ^128m2I.

Contents

See also: List of individual Iodine isotopes (and general data sources).

General data

Name of the isotope:Iodine-128m2; I-128m2Other names:Jod-128m2Symbol:^128m2I or 128m253IMass number A:128 (= number of nucleons)Atomic number Z:53 (= number of protons)Neutrons N:75Isotopic mass:127.905809(4) u (atomic weight of Iodine-128m2)
Excitation energy: 167.368(4) keVNuclide mass:127.8767361 u (calculated nuclear mass without electrons)Mass excess:-87.73835 MeVMass defect:1.158786396 u (per nucleus)Nuclear binding energy:1079.40257516 MeV (per nucleus)
8.43283262 MeV (average binding energy per nucleon)Half-life:175(15) nsDecay constant λ:3960841.0317711 s^-1Specific activity α:1.878168710011 × 10⁺²⁸ Bq g^-1
5.076131648678 × 10⁺¹⁷ Ci g^-1Spin and parity:
(nuclear angular momentum)(6)-

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
¹²⁸I		24.99(2) min	1+
^128m1I	137.851(3) keV	0.845(20) μs	4-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 75) and isobaric (same nucleon number A = 128) with Iodine-128m2. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 75	Isobar A = 128
42	¹¹⁷Mo
43	¹¹⁸Tc
44	¹¹⁹Ru
45	¹²⁰Rh
46	¹²¹Pd	¹²⁸Pd
47	¹²²Ag	¹²⁸Ag
48	¹²³Cd	¹²⁸Cd
49	¹²⁴In	¹²⁸In
50	¹²⁵Sn	¹²⁸Sn
51	¹²⁶Sb	¹²⁸Sb
52	¹²⁷Te	¹²⁸Te
53	¹²⁸I	¹²⁸I
54	¹²⁹Xe	¹²⁸Xe
55	¹³⁰Cs	¹²⁸Cs
56	¹³¹Ba	¹²⁸Ba
57	¹³²La	¹²⁸La
58	¹³³Ce	¹²⁸Ce
59	¹³⁴Pr	¹²⁸Pr
60	¹³⁵Nd	¹²⁸Nd
61	¹³⁶Pm	¹²⁸Pm
62	¹³⁷Sm	¹²⁸Sm
63	¹³⁸Eu
64	¹³⁹Gd
65	¹⁴⁰Tb
66	¹⁴¹Dy
67	¹⁴²Ho
68	¹⁴³Er
69	¹⁴⁴Tm