See also: List of individual Tellurium isotopes (and general data sources).
General data
Name of the isotope:Tellurium-120; Te-120Symbol:120Te or 12052TeMass number A:120 (= number of nucleons)Atomic number Z:52 (= number of protons)Neutrons N:68Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.3076923076923 (= neutron-proton ratio)Neutron excess (N-Z):16Isotopic mass:119.90406(2) u (atomic weight of Tellurium-120)Nuclide mass:119.8755356 u (calculated nuclear mass without electrons)Mass excess:-89.36753 MeVMass defect:1.092055952 u (per nucleus)Nuclear binding energy:1017.24356695 MeV (per nucleus) 8.47702972 MeV (average binding energy per nucleon)Separation energy:SN = 10.258(9) MeV (first neutron) SP = 7.183(8) MeV (first proton)Half-life:stableSpin and parity: (nuclear angular momentum)0+Charge radius:4.7038(88) femtometer fmYear of discovery:1936
Comparison of the natural Tellurium isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):
Atomic Mass ma
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 years
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 years
0+
Isotope 130Te
129.90622275(8) u
34.08(62) %
0.79 × 1021 years
0+
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 68) and isobaric (same nucleon number A = 120) with Tellurium-120. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
