Tin-125

Properties and data of the isotope ¹²⁵Sn.

Content

General data

Name of the isotope:Tin-125; Sn-125Symbol:¹²⁵Sn or 12550SnMass number A:125 (= number of nucleons)Atomic number Z:50 (= number of protons)Neutrons N:75Isotopic mass:124.9077864(11) u (atomic weight of Tin-125)Nuclide mass:124.880359 u (calculated nuclear mass without electrons)Mass excess:-85.89642 MeVMass defect:1.1333339 u (per nucleus)Nuclear binding energy:1055.69372785 MeV (per nucleus)
8.44554982 MeV (average binding energy per nucleon)Separation energy:S_N = 5.7335(2) MeV (first neutron)
S_P = 12.32(3) MeV (first proton)Half-life:9.64(3) dDecay constant λ:8.322133622444 × 10^-7 s^-1Specific activity α:4.041698462062 × 10⁺¹⁵ Bq g^-1
109235.09356926 Ci g^-1Spin and parity:
(nuclear angular momentum)11/2-Magnetic dipole moment:μ(μ_N) = - 1.346(2)Quadrupole moment Q:+ 0.14 barn (100 fm²)Nuclear g-factor:g_l = -0.24472727272727Charge radius:4.6765(26) femtometer fmYear of discovery:1939

Radioactive Decay

Half-life T_½ = 9.64(3) d respectively 8.32896 × 10⁵ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹²⁵Sb	100 %	2.3599(26) MeV

Parent Nuclides

Direct parent isotope is: ¹²⁵In.

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
^125mSn	27.50(14) keV	9.52(5) min	3/2+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 75) and isobaric (same nucleon number A = 125) with Tin-125. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 75	Isobar A = 125
42	¹¹⁷Mo
43	¹¹⁸Tc
44	¹¹⁹Ru
45	¹²⁰Rh	¹²⁵Rh
46	¹²¹Pd	¹²⁵Pd
47	¹²²Ag	¹²⁵Ag
48	¹²³Cd	¹²⁵Cd
49	¹²⁴In	¹²⁵In
50	¹²⁵Sn	¹²⁵Sn
51	¹²⁶Sb	¹²⁵Sb
52	¹²⁷Te	¹²⁵Te
53	¹²⁸I	¹²⁵I
54	¹²⁹Xe	¹²⁵Xe
55	¹³⁰Cs	¹²⁵Cs
56	¹³¹Ba	¹²⁵Ba
57	¹³²La	¹²⁵La
58	¹³³Ce	¹²⁵Ce
59	¹³⁴Pr	¹²⁵Pr
60	¹³⁵Nd	¹²⁵Nd
61	¹³⁶Pm
62	¹³⁷Sm
63	¹³⁸Eu
64	¹³⁹Gd
65	¹⁴⁰Tb
66	¹⁴¹Dy
67	¹⁴²Ho
68	¹⁴³Er
69	¹⁴⁴Tm