section_path: Neutrons and protons bound in a nucleus/Competition of beta decay types
section_name: Competition of beta decay types
paragraph_text: Competition of beta decay types
  
  Three types of beta decay in competition are illustrated by the single isotope copper-64 (29 protons, 35 neutrons), which has a half-life of about 12.7 hours. This isotope has one unpaired proton and one unpaired neutron, so either the proton or the neutron can decay. This particular nuclide is almost equally likely to undergo proton decay (by positron emission, 18% or by electron capture, 43%; both forming Ni) or neutron decay (by electron emission, 39%; forming Zn).