Final answer:
Beta minus decay occurs when a neutron converts into a proton, emitting an electron. Beta plus decay occurs when a proton converts into a neutron, emitting a positron.
Step-by-step explanation:
Beta minus decay (β-) occurs when a neutron within the nucleus of an atom converts into a proton, and in the process emits an electron (β- particle) and a neutrino. This decay results in the atomic number (Z) of the nucleus increasing by one while the mass number (A) remains unchanged.
Beta plus decay (β+) occurs when a proton within the nucleus of an atom converts into a neutron, emitting a positron (β+ particle) and a neutrino. This decay results in the atomic number (Z) of the nucleus decreasing by one while the mass number (A) remains unchanged.
Both types of beta decay help to maintain the balance between protons and neutrons within the nucleus, allowing for the stability of atoms.