Combining our understanding of mass number and atomic number, we are able to produce decay equations to track what is happening in a radioactive decay event.

This image shows the form of a decay equation. It shows a generic parent nuclide 'X' with atomic numbers A and Z decaying - indicated by an arrow - to a daughter nuclide 'Y' with A and Z and some radiation product also with A and Z. Each term is illustrated with pictures of a parent nuclide, daughter nuclide, and radiation products. These products are Alpha, Beta, or Gamma.