Copper (Cu) has two stable isotopes, 63Cu and 65Cu, along with 27 radioisotopes. The most stable of these is 67Cu with a half-life of 61.83 hours. The least stable is 54Cu with a half-life of approximately 75 ns. Most have half-lives under a minute. Unstable copper isotopes with atomic masses below 63 tend to undergo β+ decay, while isotopes with atomic masses above 65 tend to undergo β− decay. 64Cu decays by both β+ and β−.
Contents
68Cu, 69Cu, 71Cu, 72Cu, and 76Cu each have one metastable isomer. 70Cu has two isomers, making a total of 7 distinct isomers. The most stable of these is 68mCu with a half-life of 3.75 minutes. The least stable is 69mCu with a half-life of 360 ns.
Relative atomic mass: 63.546(3).
Notes
Medical Applications
Copper offers a relatively large number of radioisotopes that are potentially suitable for use in nuclear medicine.
There is a growing interest in the use of 64Cu, 62Cu, 61Cu, and 60Cu for diagnostic purposes and 67Cu and 64Cu for targeted radiotherapy. For example, 64Cu has a longer half-life and is thus ideal for diagnostic PET imaging of biological molecules.