Cerium-136m

Properties and data of the isotope ¹³⁶Ce.

Content

General data

Name of the isotope:Cerium-136m; Ce-136mSymbol:¹³⁶Ce or 13658CeMass number A:136 (= number of nucleons)Atomic number Z:58 (= number of protons)Neutrons N:78Isotopic mass:135.907129(3) u (atomic weight of Cerium-136m)
Excitation energy: 3095.0(6) keVNuclide mass:135.8753136 u (calculated nuclear mass without electrons)Mass excess:-86.50878 MeVMass defect:1.222586304 u (per nucleus)Nuclear binding energy:1138.83180666 MeV (per nucleus)
8.37376328 MeV (average binding energy per nucleon)Half-life:1.9(1) μsDecay constant λ:364814.30555787 s^-1Specific activity α:1.627380100584 × 10⁺²⁷ Bq g^-1
4.398324596175 × 10⁺¹⁶ Ci g^-1Spin and parity:
(nuclear angular momentum)10+Magnetic dipole moment:μ(μ_N) = -1.80(2)Nuclear g-factor:g_l = -0.18

Radioactive Decay

Half-life T_½ = 1.9(1) μs respectively 1.9 × 10^-6 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	¹³⁶Ce	100 %

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
¹³⁶Ce		stable	0+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 78) and isobaric (same nucleon number A = 136) with Cerium-136m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 78	Isobar A = 136
43	¹²¹Tc
44	¹²²Ru
45	¹²³Rh
46	¹²⁴Pd
47	¹²⁵Ag
48	¹²⁶Cd
49	¹²⁷In	¹³⁶In
50	¹²⁸Sn	¹³⁶Sn
51	¹²⁹Sb	¹³⁶Sb
52	¹³⁰Te	¹³⁶Te
53	¹³¹I	¹³⁶I
54	¹³²Xe	¹³⁶Xe
55	¹³³Cs	¹³⁶Cs
56	¹³⁴Ba	¹³⁶Ba
57	¹³⁵La	¹³⁶La
58	¹³⁶Ce	¹³⁶Ce
59	¹³⁷Pr	¹³⁶Pr
60	¹³⁸Nd	¹³⁶Nd
61	¹³⁹Pm	¹³⁶Pm
62	¹⁴⁰Sm	¹³⁶Sm
63	¹⁴¹Eu	¹³⁶Eu
64	¹⁴²Gd	¹³⁶Gd
65	¹⁴³Tb	¹³⁶Tb
66	¹⁴⁴Dy
67	¹⁴⁵Ho
68	¹⁴⁶Er
69	¹⁴⁷Tm
70	¹⁴⁸Yb
71	¹⁴⁹Lu