What is the daughter nucleus produced when 64Cu undergoes beta decay?
β-decay is when either a proton decays into a neutron, releasing a positron, or a neutron decays into a proton, releasing an electron.
Assuming that we are dealing with neutron decay, the mass number does not change, because protons and neutrons weigh the same, and the atomic number increases by one, as a new proton is being formed from a neutron. Because the atomic number changes, this is actually a new element: number 30, since one more proton is added to number 29.
On the periodic table, this is zinc, written as
As an equation, this looks like
Check that the numbers on the top and bottom add up so mass and charge are conserved.
If we are looking at a proton decaying into a neutron, emitting a positron, the equation would be