Cu65

Cu65, also written as 65Cu, is a stable isotope of copper with a mass number of 65. It has 29 protons, the atomic number of copper, and 36 neutrons (65 − 29 = 36). It is one of the two stable copper isotopes; the other is 63Cu. In nature, copper consists of about 69.2% 63Cu and about 30.8% 65Cu, with the remainder consisting of trace or unstable isotopes produced by various natural processes.

As a stable nuclide, 65Cu does not decay over geological timescales and has no radioactive half-life. Chemically, it behaves like other copper isotopes, so isotopic composition does not alter the element’s chemistry or its compounds. The isotope is naturally present in copper-containing minerals and materials in amounts corresponding to its natural abundance.

65Cu is of interest in scientific research because it is NMR-active, making it useful in certain nuclear magnetic resonance experiments to study copper-containing compounds and materials. Its stable nature and relatively abundant presence in natural copper also make it a common reference point in isotopic analysis and in calibration of mass spectrometry and other analytical techniques.

See also copper, copper isotopes, and isotopic analysis.