what type of reaction is the decay of carbon-14
Carbon-14 There are three naturally occurring isotopes of carbon on Earth: 99% of the carbon is carbon-12, 1% is carbon-13, and carbon-14 occurs in trace amounts, i.e., making up about 1 or 1.5 atoms per 1012 atoms of the carbon in the atmosphere. Carbon-12 and carbon-13 are both stable, while the half-life of carbon-14 is 5,730±40 years.[3] Carbon-14 decays into nitrogen-14 through beta decay.[4] A gram of carbon containing 1 atom of carbon-14 per 1012 atoms will emit 0.2[5] beta particles per second. The primary natural source of carbon-14 on Earth is cosmic ray action on nitrogen in the atmosphere, and it is therefore a cosmogenic nuclide. However, open-air nuclear testing between 1955–1980 contributed to this pool.
Copper-64 64Cu has a half-life of 12.701 ± 0.002 hours and decays by 17.86 (± 0.14)% by positron emission to 64Ni, 39.0 (± 0.3)% by beta decay to 64Zn, 43.075 (± 0.500)% by electron capture to 64Ni, 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.[1]