Xenon-140

Properties and data of the isotope ¹⁴⁰Xe.

Content

General data

Name of the isotope:Xenon-140; Xe-140Symbol:¹⁴⁰Xe or 14054XeMass number A:140 (= number of nucleons)Atomic number Z:54 (= number of protons)Neutrons N:86Isotopic mass:139.9216458(25) u (atomic weight of Xenon-140)Nuclide mass:139.8920244 u (calculated nuclear mass without electrons)Mass excess:-72.98647 MeVMass defect:1.246088704 u (per nucleus)Nuclear binding energy:1160.72415124 MeV (per nucleus)
8.29088679 MeV (average binding energy per nucleon)Separation energy:S_N = 5.413(3) MeV (first neutron)
S_P = 11.804(5) MeV (first proton)Half-life:13.60(10) sDecay constant λ:0.050966704452937 s^-1Specific activity α:2.20811995239 × 10⁺²⁰ Bq g^-1
5967891763.2189 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Charge radius:4.8566(125) femtometer fmYear of discovery:1951

Radioactive Decay

Half-life T_½ = 13.60(10) s respectively 1.360 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁴⁰Cs	100 %	4.064(9) MeV

Parent Nuclides

Direct parent isotopes are: ¹⁴⁰I, ²⁵²Cf.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 86) and isobaric (same nucleon number A = 140) with Xenon-140. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 86	Isobar A = 140
48	¹³⁴Cd
49	¹³⁵In
50	¹³⁶Sn
51	¹³⁷Sb	¹⁴⁰Sb
52	¹³⁸Te	¹⁴⁰Te
53	¹³⁹I	¹⁴⁰I
54	¹⁴⁰Xe	¹⁴⁰Xe
55	¹⁴¹Cs	¹⁴⁰Cs
56	¹⁴²Ba	¹⁴⁰Ba
57	¹⁴³La	¹⁴⁰La
58	¹⁴⁴Ce	¹⁴⁰Ce
59	¹⁴⁵Pr	¹⁴⁰Pr
60	¹⁴⁶Nd	¹⁴⁰Nd
61	¹⁴⁷Pm	¹⁴⁰Pm
62	¹⁴⁸Sm	¹⁴⁰Sm
63	¹⁴⁹Eu	¹⁴⁰Eu
64	¹⁵⁰Gd	¹⁴⁰Gd
65	¹⁵¹Tb	¹⁴⁰Tb
66	¹⁵²Dy	¹⁴⁰Dy
67	¹⁵³Ho	¹⁴⁰Ho
68	¹⁵⁴Er
69	¹⁵⁵Tm
70	¹⁵⁶Yb
71	¹⁵⁷Lu
72	¹⁵⁸Hf
73	¹⁵⁹Ta
74	¹⁶⁰W
75	¹⁶¹Re
76	¹⁶²Os