AAMC FL Practice Exam

In beta minus decay, which particles are emitted?

1. Neutrino and positron

2. Electron and antineutrino

3. Alpha particle

4. Photons

The correct answer is: Electron and antineutrino

In beta minus decay, a neutron in the nucleus of an atom is transformed into a proton, and in the process, an electron and an electron antineutrino are emitted. This decay occurs as a way for the nucleus to achieve a more stable configuration. The emitted electron is referred to as a beta particle, and the electron antineutrino is a nearly massless particle that carries away some of the energy released in the decay process. This conservation of energy and momentum is essential in the decay process, explaining why both the electron and neutrino are produced. The other options do not match the characteristics of beta minus decay. Positrons are emitted in beta plus decay, so they would not be found in beta minus decay. Alpha particles consist of two protons and two neutrons and are not involved in beta decay, while photons are associated with electromagnetic radiation and are not emitted during this specific type of nuclear decay.