Antimony-125

Properties and data of the isotope ¹²⁵Sb.

Content

General data

Name of the isotope:Antimony-125; Sb-125Symbol:¹²⁵Sb or 12551SbMass number A:125 (= number of nucleons)Atomic number Z:51 (= number of protons)Neutrons N:74Isotopic mass:124.9052530(28) u (atomic weight of Antimony-125)Nuclide mass:124.8772771 u (calculated nuclear mass without electrons)Mass excess:-88.25626 MeVMass defect:1.135027416 u (per nucleus)Nuclear binding energy:1057.27122784 MeV (per nucleus)
8.45816982 MeV (average binding energy per nucleon)Separation energy:S_N = 8.7073(21) MeV (first neutron)
S_P = 7.3110(26) MeV (first proton)Half-life:2.75856(25) aDecay constant λ:7.96776322055 × 10^-9 s^-1Specific activity α:38695961655479 Bq g^-1
1045.8368014994 Ci g^-1Spin and parity:
(nuclear angular momentum)7/2+Magnetic dipole moment:μ(μ_N) = + 2.63(4)Nuclear g-factor:g_l = 0.75142857142857Year of discovery:1951

Radioactive Decay

Half-life T_½ = 2.75856(25) a respectively 8.699394816 × 10⁷ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹²⁵Te	100 %	0.7666(21) MeV

Parent Nuclides

Direct parent isotope is: ¹²⁵Sn.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 74) and isobaric (same nucleon number A = 125) with Antimony-125. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 74	Isobar A = 125
41	¹¹⁵Nb
42	¹¹⁶Mo
43	¹¹⁷Tc
44	¹¹⁸Ru
45	¹¹⁹Rh	¹²⁵Rh
46	¹²⁰Pd	¹²⁵Pd
47	¹²¹Ag	¹²⁵Ag
48	¹²²Cd	¹²⁵Cd
49	¹²³In	¹²⁵In
50	¹²⁴Sn	¹²⁵Sn
51	¹²⁵Sb	¹²⁵Sb
52	¹²⁶Te	¹²⁵Te
53	¹²⁷I	¹²⁵I
54	¹²⁸Xe	¹²⁵Xe
55	¹²⁹Cs	¹²⁵Cs
56	¹³⁰Ba	¹²⁵Ba
57	¹³¹La	¹²⁵La
58	¹³²Ce	¹²⁵Ce
59	¹³³Pr	¹²⁵Pr
60	¹³⁴Nd	¹²⁵Nd
61	¹³⁵Pm
62	¹³⁶Sm
63	¹³⁷Eu
64	¹³⁸Gd
65	¹³⁹Tb
66	¹⁴⁰Dy
67	¹⁴¹Ho