Tellurium-138

Properties and data of the isotope ¹³⁸Te.

Content

General data

Name of the isotope:Tellurium-138; Te-138Symbol:¹³⁸Te or 13852TeMass number A:138 (= number of nucleons)Atomic number Z:52 (= number of protons)Neutrons N:86Isotopic mass:137.929472(4) u (atomic weight of Tellurium-138)Nuclide mass:137.9009476 u (calculated nuclear mass without electrons)Mass excess:-65.69641 MeVMass defect:1.22261244 u (per nucleus)Nuclear binding energy:1138.85615219 MeV (per nucleus)
8.25258081 MeV (average binding energy per nucleon)Separation energy:S_N = 4.464(4) MeV (first neutron)
S_P = 12.92(5) MeV (first proton)Half-life:1.4(4) sDecay constant λ:0.49510512897139 s^-1Specific activity α:2.176345129301 × 10⁺²¹ Bq g^-1
58820138629.768 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Year of discovery:1975

Radioactive Decay

Half-life T_½ = 1.4(4) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹³⁸I	93.7 %	6.284(7) MeV
β^-, n	¹³⁷I	6.3 %	2.589(9) 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 = 86) and isobaric (same nucleon number A = 138) with Tellurium-138. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 86	Isobar A = 138
48	¹³⁴Cd
49	¹³⁵In
50	¹³⁶Sn	¹³⁸Sn
51	¹³⁷Sb	¹³⁸Sb
52	¹³⁸Te	¹³⁸Te
53	¹³⁹I	¹³⁸I
54	¹⁴⁰Xe	¹³⁸Xe
55	¹⁴¹Cs	¹³⁸Cs
56	¹⁴²Ba	¹³⁸Ba
57	¹⁴³La	¹³⁸La
58	¹⁴⁴Ce	¹³⁸Ce
59	¹⁴⁵Pr	¹³⁸Pr
60	¹⁴⁶Nd	¹³⁸Nd
61	¹⁴⁷Pm	¹³⁸Pm
62	¹⁴⁸Sm	¹³⁸Sm
63	¹⁴⁹Eu	¹³⁸Eu
64	¹⁵⁰Gd	¹³⁸Gd
65	¹⁵¹Tb	¹³⁸Tb
66	¹⁵²Dy	¹³⁸Dy
67	¹⁵³Ho
68	¹⁵⁴Er
69	¹⁵⁵Tm
70	¹⁵⁶Yb
71	¹⁵⁷Lu
72	¹⁵⁸Hf
73	¹⁵⁹Ta
74	¹⁶⁰W
75	¹⁶¹Re
76	¹⁶²Os