Cerium-126

Properties and data of the isotope ¹²⁶Ce.

Content

General data

Name of the isotope:Cerium-126; Ce-126Symbol:¹²⁶Ce or 12658CeMass number A:126 (= number of nucleons)Atomic number Z:58 (= number of protons)Neutrons N:68Isotopic mass:125.92397(3) u (atomic weight of Cerium-126)Nuclide mass:125.8921546 u (calculated nuclear mass without electrons)Mass excess:-70.82149 MeVMass defect:1.119096144 u (per nucleus)Nuclear binding energy:1042.43134356 MeV (per nucleus)
8.27326463 MeV (average binding energy per nucleon)Separation energy:S_N = 12.23(29) MeV (first neutron)
S_P = 4.35(4) MeV (first proton)Half-life:51.0(3) sDecay constant λ:0.01359112118745 s^-1Specific activity α:6.547811698823 × 10⁺¹⁹ Bq g^-1
1769678837.5199 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Year of discovery:1978

Radioactive Decay

Half-life T_½ = 51.0(3) s respectively 5.10 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EE/β⁺	¹²⁶La	100 %	4.15(9) MeV

Parent Nuclides

Direct parent isotope is: ¹²⁶Pr.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 68) and isobaric (same nucleon number A = 126) with Cerium-126. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 68	Isobar A = 126
38	¹⁰⁶Sr
39	¹⁰⁷Y
40	¹⁰⁸Zr
41	¹⁰⁹Nb
42	¹¹⁰Mo
43	¹¹¹Tc
44	¹¹²Ru
45	¹¹³Rh	¹²⁶Rh
46	¹¹⁴Pd	¹²⁶Pd
47	¹¹⁵Ag	¹²⁶Ag
48	¹¹⁶Cd	¹²⁶Cd
49	¹¹⁷In	¹²⁶In
50	¹¹⁸Sn	¹²⁶Sn
51	¹¹⁹Sb	¹²⁶Sb
52	¹²⁰Te	¹²⁶Te
53	¹²¹I	¹²⁶I
54	¹²²Xe	¹²⁶Xe
55	¹²³Cs	¹²⁶Cs
56	¹²⁴Ba	¹²⁶Ba
57	¹²⁵La	¹²⁶La
58	¹²⁶Ce	¹²⁶Ce
59	¹²⁷Pr	¹²⁶Pr
60	¹²⁸Nd	¹²⁶Nd
61	¹²⁹Pm	¹²⁶Pm
62	¹³⁰Sm
63	¹³¹Eu