Not necessarily. It depends on the medium in which 64Cu was initially present

The oxidation stage must be the same, in my opinion.

Dear Reidinger, The decay is a nuclear phenomena. So the daughter nuclide that is formed will be in its atomic state. The parent nuclide formed may leave some vacancy in the crystal structure of CuCl2. If the daughter is isostructural, can occupy the vacant place and form ZnCl2.

Dear Reidinger: nuclear decay is a nuclear phenomena. So the daughter nuclide that is formed must be the same atomic state. Not crystalline structure is modified.

See Bohr theory on nuclear reaction.

The recoil effect in this case isn't a real matter because of the type of decay: the small mass electron and positron emission even with neutrino can't give that amount of the energy to the new nucleus that it can be escape from the chemical bond. Additionally the Zn and Ni have a well described oxidation stage: it is +2. Please find our paper from above mentioned theory.

Dear Mr. Riedinger, it is in principle as the colleagues above wrote. Final oxidation

state depends on the environment, but in majority cases it is to be expected that

both metals will appear as 2+ cations.

Dear Andreas, you can see from the previous answers that it is impossible to tell for sure if any or all of the decay products remain in the same oxidation state. However, unless you are handling incredibly high amounts of activity, whatever is the resulting oxidation state of you products will not affect you system significantly. Remember that A=(lambda)N, so the amount of decay products are in nano, pico and sometimes fento concentrations. There are other processes (like radiolysis) that are far more important. Hope it helps...

A very complex sequence of events takes place. The Zn or Ni produced immediately can have "shaken off" a large number of electrons, frequently exceeding the number of valence electrons. You'll have highly charged cations rattling around in a cage of ligands and subjected to electron rearrangements that are not completely understood, but easily studied. Since you don't specify the time scale of interest, the safest conclusion is that "eventually" you'll be back to the +2 states.

Dear Reidinger: I do not think that the oxidation state be the same, as it may change during the process of nuclear decay. So that the daughter nuclide formed need not have the same atomic state.

http://nucleardata.nuclear.lu.se/toi/nuclide.asp?iZA=290064

Due to the absence of Auger electrons the possibility of higher positive oxidation stage( Zn 3+) is very low.

The initial oxidation state is irrelevant, since the recoil energy is sufficient to ionize the product nucleus.

Dear colleagues, I think that Mr. Riedinger was mainly interested in the final oxidation state of born Zn or Ni, although the processes that contribute to the stabilization of an oxidation state are undoubtedly very complex. I think that we can agree that in the case of Zn, Zn(2+) is expected to be dominant product, if the environment is not highly reducing. In the case of Ni, I would also expect Ni(2+) in majority of cases, although we cannot exclude also formation of Ni(3+) if reasonably stable under given conditions (environment). In general, stabilization in final oxidation state depends in the end on the chemical environment of the decaying atom and chemical properties of the born atom (element).

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 64Ni, and 0.475 (± 0.010)% gamma radiation/internal conversion. When Cu-64 neutral it has 29 protons means that it has 29 electrons. When it decays to Zn-64 by beta decay which it has 30 protons but 29 electrons. It means that if Cu-64 is neutral Zn-64 should be negative charged. When it decays by positron emission it should be positive charged but in threcase of eectron capture, it is neutral as is shown in attached file:

I mention following two points:

1. Nuclear decay is a nuclear process. Decay of Cu-64 by positron emission or electron emission depends only on the nuclear properties of the Cu-64.

2. The chemical reactions such as oxidation is an atomic process and dominated only by the electronic structure of the atoms of interest.

In the cases of Ni-64 and Zn-64 the only similarity is their mass number (i.e. they are isobars). Ni has an atomic number of 28 and Zn has an atomic number of 30. This implies that atoms of Ni and Zn have 28 and 30 electrons, respectively. Note that mass number of an atom arises from its nuclear properties and has no effect on its chemical behavior (e.g. U-235 and U-238 have identical chemical behavior).

Conclusion: As mentioned above only similarities of Ni-64 and Zn-64 is that they have similar mass number (a nuclear property), this does not lead to similar chemical properties (which depends on the atomic properties).

Nuclear decay is not always just a nuclear process. In the example of a nuclide that decays only by electron capture, if there are no atomic electrons (as in a stripped cosmic ray to site one example) there is no decay.

Regarding chemical effects of decay, there is an excellent chapter in Siegbahn's 1968 "Alpha, Beta and Gamma Ray Spectroscopy" volume 2 on "The Atomic and Molecular Consequences of Decay". I will cite some numbers. For Ar37 electron capture, the charge spectrum of the product Cl37 is reported up to Cl(7+); for beta-minus decay of Kr85 the charge spectrum is measured through Rb(10+); for Xe133 radioactive decay the charge spectrum for Cs133 peaks at 9+ and extends through 22+. There are very complex electron re-arrangement process that immediately follow radioactive decay and to be unaware of this is relying too much on speculation without digging further into what is known about the phenomena.