<P> Copper - 64 is a positron emitting isotope of copper, with applications for molecular radiotherapy and positron emission tomography . </P> <P> Cu has a half - life of 12.701 ± 0.002 hours and decays by 17.86 (± 0.14)% by positron emission to Ni, 39.0 (± 0.3)% by beta decay to Zn, 43.075 (± 0.500)% by electron capture to Ni, and 0.475 (± 0.010)% gamma radiation / internal conversion . These emissions are 0.5787 (± 0.0009) and 0.6531 (± 0.0002) MeV for beta minus and positron respectively and 1.34577 (± 0.00016) MeV for gamma . </P> <P> The main oxidation states of copper are I and II since Cu is too powerful to exist in biochemical systems . Furthermore, copper (I) exists as a strong complex in aqueous solution and is not often seen . Copper (II) forms mononuclear complexes that are paramagnetic and prefers ligands of sulfur and nitrogen . </P>

When a nucleus of the copper isotope 64cu emits a positron it becomes
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