Xenon-120

Properties and data of the isotope ¹²⁰Xe.

Content

General data

Name of the isotope:Xenon-120; Xe-120Symbol:¹²⁰Xe or 12054XeMass number A:120 (= number of nucleons)Atomic number Z:54 (= number of protons)Neutrons N:66Isotopic mass:119.911784(13) u (atomic weight of Xenon-120)Nuclide mass:119.8821626 u (calculated nuclear mass without electrons)Mass excess:-82.17267 MeVMass defect:1.082652184 u (per nucleus)Nuclear binding energy:1008.48401348 MeV (per nucleus)
8.40403345 MeV (average binding energy per nucleon)Separation energy:S_N = 11.449(16) MeV (first neutron)
S_P = 5.70(3) MeV (first proton)Half-life:40(1) minDecay constant λ:0.00028881132523331 s^-1Specific activity α:1.461565111344 × 10⁺¹⁸ Bq g^-1
39501759.766068 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Charge radius:4.7509(63) femtometer fmYear of discovery:1965

Radioactive Decay

Half-life T_½ = 40(1) min (minutes) respectively 2.400 × 10³ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EE/β⁺	¹²⁰I	100 %	1.581(19) MeV

Parent Nuclides

Direct parent isotope is: ¹²⁰Cs.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 66) and isobaric (same nucleon number A = 120) with Xenon-120. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 66	Isobar A = 120
37	¹⁰³Rb
38	¹⁰⁴Sr
39	¹⁰⁵Y
40	¹⁰⁶Zr
41	¹⁰⁷Nb
42	¹⁰⁸Mo
43	¹⁰⁹Tc	¹²⁰Tc
44	¹¹⁰Ru	¹²⁰Ru
45	¹¹¹Rh	¹²⁰Rh
46	¹¹²Pd	¹²⁰Pd
47	¹¹³Ag	¹²⁰Ag
48	¹¹⁴Cd	¹²⁰Cd
49	¹¹⁵In	¹²⁰In
50	¹¹⁶Sn	¹²⁰Sn
51	¹¹⁷Sb	¹²⁰Sb
52	¹¹⁸Te	¹²⁰Te
53	¹¹⁹I	¹²⁰I
54	¹²⁰Xe	¹²⁰Xe
55	¹²¹Cs	¹²⁰Cs
56	¹²²Ba	¹²⁰Ba
57	¹²³La	¹²⁰La
58	¹²⁴Ce	¹²⁰Ce
59	¹²⁵Pr
60	¹²⁶Nd
61	¹²⁷Pm
62	¹²⁸Sm