Xenon-136

Properties and data of the isotope ¹³⁶Xe.

Contents

General data

Name of the isotope:Xenon-136; Xe-136Symbol:¹³⁶Xe or 13654XeMass number A:136 (= number of nucleons)Atomic number Z:54 (= number of protons)Neutrons N:82Isotopic mass:135.90721448(7) u (atomic weight of Xenon-136)Nuclide mass:135.8775931 u (calculated nuclear mass without electrons)Mass excess:-86.42916 MeVMass defect:1.22586036 u (per nucleus)Nuclear binding energy:1141.88157018 MeV (per nucleus)
8.39618802 MeV (average binding energy per nucleon)Separation energy:S_N = 8.087(4) MeV (first neutron)
S_P = 9.9390(21) MeV (first proton)Half-life:2.165(61) × 10²¹ aDecay constant λ:1.015221843403 × 10^-29 s^-1Specific activity α:4.528747366712 × 10^-8 Bq g^-1
1.223985774787 × 10^-18 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Charge radius:4.7964(47) femtometer fmYear of discovery:1920

Radioactive Decay

Half-life T_½ = 2.165(61) × 10²¹ a respectively 6.827544 × 10²⁸ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
2 β^-	¹³⁶Ba	100 %

Parent Nuclides

Direct parent isotopes are: ¹³⁶I, ¹³⁷I, ²⁴⁸Cm, ²⁵²Cf.

Occurrence

Comparison of the natural Xenon isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):

	Atomic Mass m_a	Quantity	Half-life	Spin
Xenon Isotopic mixture	131.293 u	100 %
Isotope ¹²⁴Xe	123.90589(2) u	0.095(5) %	> 1.8 × 10²² a	0+
Isotope ¹²⁶Xe	125.90430(3) u	0.089(3) %	stable	0+
Isotope ¹²⁸Xe	127.903531(7) u	1.910(13) %	stable	0+
Isotope ¹²⁹Xe	128.90478086(4) u	26.401(138) %	stable	1/2+
Isotope ¹³⁰Xe	129.9035094(1) u	4.071(22) %	stable	0+
Isotope ¹³¹Xe	130.905084(2) u	21.232(51) %	stable	3/2+
Isotope ¹³²Xe	131.90415509(4) u	26.909(55) %	stable	0+
Isotope ¹³⁴Xe	133.905393033(10) u	10.436(35) %	5.8 × 10²² a	0+
Isotope ¹³⁶Xe	135.90721448(7) u	8.857(72) %	2.165(61) × 10²¹ a	0+

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
^136mXe	1891.74(7) keV	2.95(17) μs	6+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 82) and isobaric (same nucleon number A = 136) with Xenon-136. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 82	Isobar A = 136
45	¹²⁷Rh
46	¹²⁸Pd
47	¹²⁹Ag
48	¹³⁰Cd
49	¹³¹In	¹³⁶In
50	¹³²Sn	¹³⁶Sn
51	¹³³Sb	¹³⁶Sb
52	¹³⁴Te	¹³⁶Te
53	¹³⁵I	¹³⁶I
54	¹³⁶Xe	¹³⁶Xe
55	¹³⁷Cs	¹³⁶Cs
56	¹³⁸Ba	¹³⁶Ba
57	¹³⁹La	¹³⁶La
58	¹⁴⁰Ce	¹³⁶Ce
59	¹⁴¹Pr	¹³⁶Pr
60	¹⁴²Nd	¹³⁶Nd
61	¹⁴³Pm	¹³⁶Pm
62	¹⁴⁴Sm	¹³⁶Sm
63	¹⁴⁵Eu	¹³⁶Eu
64	¹⁴⁶Gd	¹³⁶Gd
65	¹⁴⁷Tb	¹³⁶Tb
66	¹⁴⁸Dy
67	¹⁴⁹Ho
68	¹⁵⁰Er
69	¹⁵¹Tm
70	¹⁵²Yb
71	¹⁵³Lu
72	¹⁵⁴Hf
73	¹⁵⁵Ta
74	¹⁵⁶W