Cerium-131m

Properties and data of the isotope ^131mCe.

Contents

See also: List of individual Cerium isotopes (and general data sources).

General data

Name of the isotope:Cerium-131m; Ce-131mSymbol:^131mCe or 131m58CeMass number A:131 (= number of nucleons)Atomic number Z:58 (= number of protons)Neutrons N:73Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.2586206896552 (= neutron-proton ratio)Neutron excess (N-Z):15Excitation energy:63.09(9) keVIsotopic mass:130.91443(4) u (atomic weight of Cerium-131m)Nuclide mass:130.8826146 u (calculated nuclear mass without electrons)Mass excess:-79.70794 MeVMass defect:1.171960724 u (per nucleus)Nuclear binding energy:1091.67438264 MeV (per nucleus)
8.33339223 MeV (average binding energy per nucleon)Half-life:5.4(4) minDecay constant λ:0.0021393431498764 s^-1Specific activity α:9.910327535612 × 10⁺¹⁸ Bq g^-1
267846690.15169 Ci g^-1Spin and parity:
(nuclear angular momentum)(1/2+)Year of discovery:1966

Radioactive Decay

Half-life T_½ = 5.4(4) min (minutes) respectively 3.24 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β⁺	¹³¹La	100 %
Iso	¹³¹Ce	?

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
¹³¹Ce		10.3(3) min	7/2+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 73) and isobaric (same nucleon number A = 131) with Cerium-131m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 73	Isobar A = 131
41	¹¹⁴Nb
42	¹¹⁵Mo
43	¹¹⁶Tc
44	¹¹⁷Ru
45	¹¹⁸Rh
46	¹¹⁹Pd
47	¹²⁰Ag	¹³¹Ag
48	¹²¹Cd	¹³¹Cd
49	¹²²In	¹³¹In
50	¹²³Sn	¹³¹Sn
51	¹²⁴Sb	¹³¹Sb
52	¹²⁵Te	¹³¹Te
53	¹²⁶I	¹³¹I
54	¹²⁷Xe	¹³¹Xe
55	¹²⁸Cs	¹³¹Cs
56	¹²⁹Ba	¹³¹Ba
57	¹³⁰La	¹³¹La
58	¹³¹Ce	¹³¹Ce
59	¹³²Pr	¹³¹Pr
60	¹³³Nd	¹³¹Nd
61	¹³⁴Pm	¹³¹Pm
62	¹³⁵Sm	¹³¹Sm
63	¹³⁶Eu	¹³¹Eu
64	¹³⁷Gd
65	¹³⁸Tb
66	¹³⁹Dy
67	¹⁴⁰Ho