Iodine-124

Properties and data of the isotope ¹²⁴I.

Content

General Data

Radioactive Decay

Use in Medicine

Isotones und Isobares

Literature

General data

Name of the isotope:Iodine-124; I-124Other names:Jod-124Symbol:¹²⁴I or 12453IMass number A:124 (= number of nucleons)Atomic number Z:53 (= number of protons)Neutrons N:71Isotopic mass:123.9062103(25) u (atomic weight of Iodine-124)Nuclide mass:123.8771374 u (calculated nuclear mass without electrons)Mass excess:-87.36454 MeVMass defect:1.123725432 u (per nucleus)Nuclear binding energy:1046.74349756 MeV (per nucleus)
8.44147982 MeV (average binding energy per nucleon)Separation energy:S_N = 7.493(4) MeV (first neutron)
S_P = 5.4825(19) MeV (first proton)Half-life:4.1760(3) dDecay constant λ:1.921105558437 × 10^-6 s^-1Specific activity α:9.405827869691 × 10⁺¹⁵ Bq g^-1
254211.56404571 Ci g^-1Spin and parity:
(nuclear angular momentum)2-Magnetic dipole moment:μ(μ_N) = 1.444(4)Nuclear g-factor:g_l = 0.722Year of discovery:1938

Radioactive Decay

Half-life T_½ = 4.1760(3) d respectively 3.608064 × 10⁵ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EE/β⁺	¹²⁴Te	100 %	3.1596(27) MeV

Iodine-124 as a Radionuclide in Medicine

Iodine-124, in the form of an iodide salt, can be used to image the thyroid gland using positron emission tomography (PET). When used as a tracer, the radionuclide is chemically bound to appropriate drug molecules; the positron-emitting radiopharmaceuticals thus formed are injected into the body; the radiation emitted by the ¹²⁴I radionuclide can in turn be recorded using a PET scan.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 71) and isobaric (same nucleon number A = 124) with Iodine-124. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 71	Isobar A = 124
40	¹¹¹Zr
41	¹¹²Nb
42	¹¹³Mo
43	¹¹⁴Tc
44	¹¹⁵Ru	¹²⁴Ru
45	¹¹⁶Rh	¹²⁴Rh
46	¹¹⁷Pd	¹²⁴Pd
47	¹¹⁸Ag	¹²⁴Ag
48	¹¹⁹Cd	¹²⁴Cd
49	¹²⁰In	¹²⁴In
50	¹²¹Sn	¹²⁴Sn
51	¹²²Sb	¹²⁴Sb
52	¹²³Te	¹²⁴Te
53	¹²⁴I	¹²⁴I
54	¹²⁵Xe	¹²⁴Xe
55	¹²⁶Cs	¹²⁴Cs
56	¹²⁷Ba	¹²⁴Ba
57	¹²⁸La	¹²⁴La
58	¹²⁹Ce	¹²⁴Ce
59	¹³⁰Pr	¹²⁴Pr
60	¹³¹Nd	¹²⁴Nd
61	¹³²Pm
62	¹³³Sm
63	¹³⁴Eu
64	¹³⁵Gd
65	¹³⁶Tb