Trace Sciences International

Tellurium Isotopes

Nominal Mass
Accurate Mass
% Natural Abundance
Chemical Form
Enrichment Available %

120 Te

119.904048 (21)

0.09 (1)

metal

24 – 40+

122 Te

121.903050 (3)

2.55 (12)

metal, oxide

91 – 93+

123 Te

122.9042710 (22)

0.89 (3)

metal, oxide

69 – 99+

124 Te

123.9028180 (18)

4.74 (8)

metal, oxide

90 – 92+

125 Te

124.9044285 (25)

7.07 (15)

metal

85 – 92+

126 Te

125.9033095 (25)

18.84 (25)

metal

96 – 98+

128 Te

127.904463

31.74

metal, oxide

74 – 99+

130 Te

129.906229 (5)

34.08 (62)

metal, oxide

99+

Tellurium has eight stable isotopes (Te-120 and Te-123 are usually considered stable because of their long half lives) and many of them have a medical application. Te-120 is used for the production of I-120g which has an application as a PET and Beta emitting isotope. Te-122 is used in the production of the radioisotope I-122 which is used in gamma imaging. Te-123 is used for the production of radioactive I-123 which is used in thyroid imaging. Te-124 is used for the production of both I-123 and the PET isotope I-124. Finally, Te-130 is used in the research into double Beta decay.