Tellurium-125

Properties and data of the isotope ¹²⁵Te.

Content

General data

Name of the isotope:Tellurium-125; Te-125Symbol:¹²⁵Te or 12552TeMass number A:125 (= number of nucleons)Atomic number Z:52 (= number of protons)Neutrons N:73Isotopic mass:124.9044312(15) u (atomic weight of Tellurium-125)Nuclide mass:124.8759068 u (calculated nuclear mass without electrons)Mass excess:-89.02176 MeVMass defect:1.135009332 u (per nucleus)Nuclear binding energy:1057.2543827 MeV (per nucleus)
8.45803506 MeV (average binding energy per nucleon)Separation energy:S_N = 6.56897(3) MeV (first neutron)
S_P = 8.69170(14) MeV (first proton)Half-life:stableSpin and parity:
(nuclear angular momentum)1/2+Magnetic dipole moment:μ(μ_N) = -0.8885051(4)Charge radius:4.7204(30) femtometer fmYear of discovery:1931

Parent Nuclides

Direct parent isotopes are: ¹²⁵I, ¹²⁵Sb.

Occurrence

Comparison of the natural Tellurium isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):

	Atomic Mass m_a	Quantity	Half-life	Spin
Tellurium Isotopic mixture	127.60 u	100 %
Isotope ¹²⁰Te	119.90406(2) u	0.09(1) %	stable	0+
Isotope ¹²²Te	121.90304(1) u	2.55(12) %	stable	0+
Isotope ¹²³Te	122.90427(1) u	0.89(3) %	9.2 × 10¹⁶ a	1/2+
Isotope ¹²⁴Te	123.90282(1) u	4.74(14) %	stable	0+
Isotope ¹²⁵Te	124.9044312(15) u	7.07(15) %	stable	1/2+
Isotope ¹²⁶Te	125.90331(1) u	18.84(25) %	stable	0+
Isotope ¹²⁸Te	127.904461(6) u	31.74(8) %	7.7(4) × 10²⁴ a	0+
Isotope ¹³⁰Te	129.90622275(8) u	34.08(62) %	0.79 × 10²¹ a	0+

NMR data

Nuclear magnetic properties of the NMR active Nuclide ¹²⁵Te

Isotope:¹²⁵Te-NMRQuantity:7.07(15) %Spin:1/2+Nuclearmagnetic moment
μ/μ_N:-0.8885051(4)Gyromagnetic ratio γ:8.5087 · 10⁷ rad T^-1 s^-1Nuclear g-factor:g_l = -1.7770102Resonance frequency:v₀ = 13.5446 at 1 TRelative Sensitivity:0.03219 (H₀ = const.)
0.3181 (v₀ = const.)
[related to ¹H = 1.000]

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
^125mTe	144.775(8) keV	57.40(15) d	11/2-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 73) and isobaric (same nucleon number A = 125) with Tellurium-125. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 73	Isobar A = 125
41	¹¹⁴Nb
42	¹¹⁵Mo
43	¹¹⁶Tc
44	¹¹⁷Ru
45	¹¹⁸Rh	¹²⁵Rh
46	¹¹⁹Pd	¹²⁵Pd
47	¹²⁰Ag	¹²⁵Ag
48	¹²¹Cd	¹²⁵Cd
49	¹²²In	¹²⁵In
50	¹²³Sn	¹²⁵Sn
51	¹²⁴Sb	¹²⁵Sb
52	¹²⁵Te	¹²⁵Te
53	¹²⁶I	¹²⁵I
54	¹²⁷Xe	¹²⁵Xe
55	¹²⁸Cs	¹²⁵Cs
56	¹²⁹Ba	¹²⁵Ba
57	¹³⁰La	¹²⁵La
58	¹³¹Ce	¹²⁵Ce
59	¹³²Pr	¹²⁵Pr
60	¹³³Nd	¹²⁵Nd
61	¹³⁴Pm
62	¹³⁵Sm
63	¹³⁶Eu
64	¹³⁷Gd
65	¹³⁸Tb
66	¹³⁹Dy
67	¹⁴⁰Ho