Tellurium-137

Properties and data of the isotope ¹³⁷Te.

Content

General data

Name of the isotope:Tellurium-137; Te-137Symbol:¹³⁷Te or 13752TeMass number A:137 (= number of nucleons)Atomic number Z:52 (= number of protons)Neutrons N:85Isotopic mass:136.9255994(23) u (atomic weight of Tellurium-137)Nuclide mass:136.897075 u (calculated nuclear mass without electrons)Mass excess:-69.30371 MeVMass defect:1.217820124 u (per nucleus)Nuclear binding energy:1134.39213859 MeV (per nucleus)
8.28023459 MeV (average binding energy per nucleon)Separation energy:S_N = 2.950(3) MeV (first neutron)
S_P = 12.086(6) MeV (first proton)Half-life:2.49(5) sDecay constant λ:0.27837236167066 s^-1Specific activity α:1.232645274627 × 10⁺²¹ Bq g^-1
33314737152.105 Ci g^-1Spin and parity:
(nuclear angular momentum)(7/2-)Year of discovery:1975

Radioactive Decay

Half-life T_½ = 2.49(5) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹³⁷I	97.01 %	7.053(9) MeV
β^-, n	¹³⁶I	2.99 %	2.170(14) MeV

Parent Nuclides

Direct parent isotope is: ²⁴⁸Cm.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 85) and isobaric (same nucleon number A = 137) with Tellurium-137. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 85	Isobar A = 137
47	¹³²Ag
48	¹³³Cd
49	¹³⁴In	¹³⁷In
50	¹³⁵Sn	¹³⁷Sn
51	¹³⁶Sb	¹³⁷Sb
52	¹³⁷Te	¹³⁷Te
53	¹³⁸I	¹³⁷I
54	¹³⁹Xe	¹³⁷Xe
55	¹⁴⁰Cs	¹³⁷Cs
56	¹⁴¹Ba	¹³⁷Ba
57	¹⁴²La	¹³⁷La
58	¹⁴³Ce	¹³⁷Ce
59	¹⁴⁴Pr	¹³⁷Pr
60	¹⁴⁵Nd	¹³⁷Nd
61	¹⁴⁶Pm	¹³⁷Pm
62	¹⁴⁷Sm	¹³⁷Sm
63	¹⁴⁸Eu	¹³⁷Eu
64	¹⁴⁹Gd	¹³⁷Gd
65	¹⁵⁰Tb	¹³⁷Tb
66	¹⁵¹Dy
67	¹⁵²Ho
68	¹⁵³Er
69	¹⁵⁴Tm
70	¹⁵⁵Yb
71	¹⁵⁶Lu
72	¹⁵⁷Hf
73	¹⁵⁸Ta
74	¹⁵⁹W
75	¹⁶⁰Re
76	¹⁶¹Os