Answer is: daughter nucleus is zinc.
Nuclear reaction 3: ⁶⁴Cu → ⁶⁴Zn + e⁻ + electron antineutrino.
Beta decay is radioactive decay in
which a beta ray and a neutrino are emitted from
an atomic nucleus.
There are two types of beta decay: beta minus and beta
plus.
In beta minus decay, neutron is converted to a proton and
an electron and an electron antineutrino and atomic number Z is increased by one.
