What characterizes beta decay in nuclear physics?

Beta decay is characterized by the emission of a beta particle from an atomic nucleus. This process can occur in two forms: beta-minus decay, where a neutron is transformed into a proton with the release of an electron (the beta particle) and an antineutrino, and beta-plus decay, where a proton is converted into a neutron with the emission of a positron (the beta particle) and a neutrino.

In both cases, beta decay results in a transformation of the nucleus and the release of energy in the form of kinetic energy carried by the emitted beta particle. This emission is fundamental to the understanding of nuclear reactions, as it highlights the conversion processes within an atomic nucleus and the balance of atomic number and mass number.

The other options do not fully encapsulate the essence of beta decay. For example, while the conversion of neutrons into protons is a part of beta-minus decay, it is not the only defining aspect of beta decay as a whole, making it too narrow. The simple emission of a positron refers specifically to beta-plus decay, and does not encompass the broader context. Emission of gamma radiation is a separate type of decay that typically occurs alongside alpha or beta decay but is not a characteristic of beta decay itself