Xenon-122

Properties and data of the isotope ¹²²Xe.

Content

General data

Name of the isotope:Xenon-122; Xe-122Symbol:¹²²Xe or 12254XeMass number A:122 (= number of nucleons)Atomic number Z:54 (= number of protons)Neutrons N:68Isotopic mass:121.908368(12) u (atomic weight of Xenon-122)Nuclide mass:121.8787466 u (calculated nuclear mass without electrons)Mass excess:-85.35466 MeVMass defect:1.103398016 u (per nucleus)Nuclear binding energy:1027.80863152 MeV (per nucleus)
8.42466091 MeV (average binding energy per nucleon)Separation energy:S_N = 10.945(15) MeV (first neutron)
S_P = 6.392(12) MeV (first proton)Half-life:20.1(1) hDecay constant λ:9.531726905389 × 10^-6 s^-1Specific activity α:4.743917525843 × 10⁺¹⁶ Bq g^-1
1282139.8718496 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Charge radius:4.7590(59) femtometer fmYear of discovery:1952

Radioactive Decay

Half-life T_½ = 20.1(1) h (hours) respectively 7.2720 × 10⁴ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EE	¹²²I	100 %	0.725(12) MeV

Parent Nuclides

Direct parent isotope is: ¹²²Cs.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 68) and isobaric (same nucleon number A = 122) with Xenon-122. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 68	Isobar A = 122
38	¹⁰⁶Sr
39	¹⁰⁷Y
40	¹⁰⁸Zr
41	¹⁰⁹Nb
42	¹¹⁰Mo
43	¹¹¹Tc
44	¹¹²Ru	¹²²Ru
45	¹¹³Rh	¹²²Rh
46	¹¹⁴Pd	¹²²Pd
47	¹¹⁵Ag	¹²²Ag
48	¹¹⁶Cd	¹²²Cd
49	¹¹⁷In	¹²²In
50	¹¹⁸Sn	¹²²Sn
51	¹¹⁹Sb	¹²²Sb
52	¹²⁰Te	¹²²Te
53	¹²¹I	¹²²I
54	¹²²Xe	¹²²Xe
55	¹²³Cs	¹²²Cs
56	¹²⁴Ba	¹²²Ba
57	¹²⁵La	¹²²La
58	¹²⁶Ce	¹²²Ce
59	¹²⁷Pr	¹²²Pr
60	¹²⁸Nd
61	¹²⁹Pm
62	¹³⁰Sm
63	¹³¹Eu