Indium-122

Properties and data of the isotope ¹²²In.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

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

General data

Name of the isotope:Indium-122; In-122Symbol:¹²²In or 12249InMass number A:122 (= number of nucleons)Atomic number Z:49 (= number of protons)Neutrons N:73Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.4897959183673 (= neutron-proton ratio)Neutron excess (N-Z):24Isotopic mass:121.91028(5) u (atomic weight of Indium-122)Nuclide mass:121.8834011 u (calculated nuclear mass without electrons)Mass excess:-83.57364 MeVMass defect:1.105685436 u (per nucleus)Nuclear binding energy:1029.93934952 MeV (per nucleus)
8.44212582 MeV (average binding energy per nucleon)Separation energy:S_N = 5.81(6) MeV (first neutron)
S_P = 9.79(5) MeV (first proton)Half-life:1.5(3) sDecay constant λ:0.4620981203733 s^-1Specific activity α:2.282678643523 × 10⁺²¹ Bq g^-1
61694017392.522 Ci g^-1Spin and parity:
(nuclear angular momentum)1+Charge radius:4.6534(51) femtometer fmYear of discovery:1963

Radioactive Decay

Half-life T_½ = 1.5(3) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹²²Sn	100 %	6.37(5) MeV

Parent Nuclides

Direct parent isotope is: ¹²²Cd.

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
^122m1In	40(60) keV	10.3(6) s	5+
^122m2In	290 keV	10.8(4) s	(8-)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 73) and isobaric (same nucleon number A = 122) with Indium-122. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 73	Isobar A = 122
41	¹¹⁴Nb
42	¹¹⁵Mo
43	¹¹⁶Tc
44	¹¹⁷Ru	¹²²Ru
45	¹¹⁸Rh	¹²²Rh
46	¹¹⁹Pd	¹²²Pd
47	¹²⁰Ag	¹²²Ag
48	¹²¹Cd	¹²²Cd
49	¹²²In	¹²²In
50	¹²³Sn	¹²²Sn
51	¹²⁴Sb	¹²²Sb
52	¹²⁵Te	¹²²Te
53	¹²⁶I	¹²²I
54	¹²⁷Xe	¹²²Xe
55	¹²⁸Cs	¹²²Cs
56	¹²⁹Ba	¹²²Ba
57	¹³⁰La	¹²²La
58	¹³¹Ce	¹²²Ce
59	¹³²Pr	¹²²Pr
60	¹³³Nd
61	¹³⁴Pm
62	¹³⁵Sm
63	¹³⁶Eu
64	¹³⁷Gd
65	¹³⁸Tb
66	¹³⁹Dy
67	¹⁴⁰Ho