Antimony-131m2

Properties and data of the isotope ¹³¹Sb.

Content

General data

Name of the isotope:Antimony-131m2; Sb-131m2Symbol:¹³¹Sb or 13151SbMass number A:131 (= number of nucleons)Atomic number Z:51 (= number of protons)Neutrons N:80Isotopic mass:130.9119893(22) u (atomic weight of Antimony-131m2)
Excitation energy: 1687.2(9) keVNuclide mass:130.8840134 u (calculated nuclear mass without electrons)Mass excess:-81.98144 MeVMass defect:1.180280612 u (per nucleus)Nuclear binding energy:1099.42430839 MeV (per nucleus)
8.39255197 MeV (average binding energy per nucleon)Half-life:4.3(8) μsDecay constant λ:161197.01873487 s^-1Specific activity α:7.467316561717 × 10⁺²⁶ Bq g^-1
2.01819366532 × 10⁺¹⁶ Ci g^-1Spin and parity:
(nuclear angular momentum)(19/2-)

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
¹³¹Sb		23.03(4) min	(7/2+)
^131m1Sb	1676.06(6) keV	91(4) μs	(15/2-)
^131m3Sb	2165.6(15) keV	1.1(2) μs	(23/2+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 80) and isobaric (same nucleon number A = 131) with Antimony-131m2. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 80	Isobar A = 131
44	¹²⁴Ru
45	¹²⁵Rh
46	¹²⁶Pd
47	¹²⁷Ag	¹³¹Ag
48	¹²⁸Cd	¹³¹Cd
49	¹²⁹In	¹³¹In
50	¹³⁰Sn	¹³¹Sn
51	¹³¹Sb	¹³¹Sb
52	¹³²Te	¹³¹Te
53	¹³³I	¹³¹I
54	¹³⁴Xe	¹³¹Xe
55	¹³⁵Cs	¹³¹Cs
56	¹³⁶Ba	¹³¹Ba
57	¹³⁷La	¹³¹La
58	¹³⁸Ce	¹³¹Ce
59	¹³⁹Pr	¹³¹Pr
60	¹⁴⁰Nd	¹³¹Nd
61	¹⁴¹Pm	¹³¹Pm
62	¹⁴²Sm	¹³¹Sm
63	¹⁴³Eu	¹³¹Eu
64	¹⁴⁴Gd
65	¹⁴⁵Tb
66	¹⁴⁶Dy
67	¹⁴⁷Ho
68	¹⁴⁸Er
69	¹⁴⁹Tm
70	¹⁵⁰Yb
71	¹⁵¹Lu