Beta decay is a type of radioactive decay in which an unstable atomic nucleus transforms into a more stable one by emitting a beta particle. This process involves the conversion of a neutron into a proton, or vice versa, resulting in the emission of an electron or a positron along with a neutrino. This transformation changes the element into a different isotope or a completely different element altogether. The emitted beta particles can be either negatively charged electrons or positively charged positrons. Beta decay plays a crucial role in nuclear reactions and is significant in various applications, including medical treatments and understanding fundamental particle interactions.