Protons, neutrons and electrons have specific values of mass number - A and atomic number - Z. It is important to remember these so we can accurately form decay equations.

This image depicts a two-by-three table containing the information for the Atomic and Mass numbers of Protons, Neutrons, and Electrons. The two vertical columns are headed A and Z and contain images of both a Proton and a Neutron in the first column and just a Proton in the second column. The three rows are ordered Proton, above Neutron, above Electron with an image representing each beside each title. The information that the table contains is that for a Proton, Neutron, and an Electron the A values are 1, 1, and 0 respectively and the Z values are 1, 0, and -1 respectively.