Cesium-136
Properties and data of the isotope 136Cs.
See also: List of individual Cesium isotopes (and general data sources).
General data
Name of the isotope:Cesium-136; Cs-136Symbol:136Cs or 13655CsMass number A:136 (= number of nucleons)Atomic number Z:55 (= number of protons)Neutrons N:81Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.4727272727273 (= neutron-proton ratio)Neutron excess (N-Z):26Isotopic mass:135.9073116(20) u (atomic weight of Cesium-136)Nuclide mass:135.8771417 u (calculated nuclear mass without electrons)Mass excess:-86.33869 MeVMass defect:1.224923356 u (per nucleus)Nuclear binding energy:1141.00875657 MeV (per nucleus)
8.38977027 MeV (average binding energy per nucleon)Separation energy:SN = 6.8284(21) MeV (first neutron)
SP = 7.215(4) MeV (first proton)Half-life:13.01(5) dDecay constant λ:6.166438748682 × 10-7 s-1Specific activity α:2.75075279620 × 10+15 Bq g-1
74344.670167649 Ci g-1Spin and parity:
(nuclear angular momentum)5+Magnetic dipole moment:μ(μN) = + 3.705(15)Quadrupole moment Q:+0.225 barn (100 fm2)Nuclear g-factor:gl = 0.741Charge radius:4.8059(52) femtometer fmYear of discovery:1951
Radioactive Decay
Half-life T½ = 13.01(5) d respectively 1.124064 × 106 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| β- | 136Ba | 100 % | 2.5482(19) MeV | |
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 |
|---|
| 136mCs | 517.9(1) keV | 17.5(2) s | 8- |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 81) and isobaric (same nucleon number A = 136) with Cesium-136. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 81 | Isobar A = 136 |
|---|
| 45 | 126Rh | |
| 46 | 127Pd | |
| 47 | 128Ag | |
| 48 | 129Cd | |
| 49 | 130In | 136In |
| 50 | 131Sn | 136Sn |
| 51 | 132Sb | 136Sb |
| 52 | 133Te | 136Te |
| 53 | 134I | 136I |
| 54 | 135Xe | 136Xe |
| 55 | 136Cs | 136Cs |
| 56 | 137Ba | 136Ba |
| 57 | 138La | 136La |
| 58 | 139Ce | 136Ce |
| 59 | 140Pr | 136Pr |
| 60 | 141Nd | 136Nd |
| 61 | 142Pm | 136Pm |
| 62 | 143Sm | 136Sm |
| 63 | 144Eu | 136Eu |
| 64 | 145Gd | 136Gd |
| 65 | 146Tb | 136Tb |
| 66 | 147Dy | |
| 67 | 148Ho | |
| 68 | 149Er | |
| 69 | 150Tm | |
| 70 | 151Yb | |
| 71 | 152Lu | |
| 72 | 153Hf | |
External data and identifiers
Last update: 2020-10-18
Perma link: https://www.chemlin.org/isotope/cesium-136
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