Samarium-133

Properties and data of the isotope ¹³³Sm.

Content

General data

Name of the isotope:Samarium-133; Sm-133Symbol:¹³³Sm or 13362SmMass number A:133 (= number of nucleons)Atomic number Z:62 (= number of protons)Neutrons N:71Isotopic mass:132.93856(32) u (atomic weight of Samarium-133)Nuclide mass:132.9045507 u (calculated nuclear mass without electrons)Mass excess:-57.23099 MeVMass defect:1.16180102 u (per nucleus)Nuclear binding energy:1082.21067932 MeV (per nucleus)
8.1369224 MeV (average binding energy per nucleon)Separation energy:S_N = 10.22(42) MeV (first neutron)
S_P = 2.89(33) MeV (first proton)Half-life:2.89(16) sDecay constant λ:0.23984331507265 s^-1Specific activity α:1.094219869455 × 10⁺²¹ Bq g^-1
29573509985.292 Ci g^-1Spin and parity:
(nuclear angular momentum)(5/2+)Year of discovery:1977

Radioactive Decay

Half-life T_½ = 2.89(16) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EE/β⁺	¹³³Pm	100 %	8.818(30) MeV
EE, p	¹³²Nd	?

Parent Nuclides

Direct parent isotope is: ¹³³Eu.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 71) and isobaric (same nucleon number A = 133) with Samarium-133. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 71	Isobar A = 133
40	¹¹¹Zr
41	¹¹²Nb
42	¹¹³Mo
43	¹¹⁴Tc
44	¹¹⁵Ru
45	¹¹⁶Rh
46	¹¹⁷Pd
47	¹¹⁸Ag
48	¹¹⁹Cd	¹³³Cd
49	¹²⁰In	¹³³In
50	¹²¹Sn	¹³³Sn
51	¹²²Sb	¹³³Sb
52	¹²³Te	¹³³Te
53	¹²⁴I	¹³³I
54	¹²⁵Xe	¹³³Xe
55	¹²⁶Cs	¹³³Cs
56	¹²⁷Ba	¹³³Ba
57	¹²⁸La	¹³³La
58	¹²⁹Ce	¹³³Ce
59	¹³⁰Pr	¹³³Pr
60	¹³¹Nd	¹³³Nd
61	¹³²Pm	¹³³Pm
62	¹³³Sm	¹³³Sm
63	¹³⁴Eu	¹³³Eu
64	¹³⁵Gd
65	¹³⁶Tb