Final answer:
Alpha particles and protons are actually nuclei; alpha particles are high-energy helium nuclei and protons are hydrogen nuclei, while beta particles are high-speed electrons and gamma rays are high-energy electromagnetic radiation, neither of which are nuclei.
Step-by-step explanation:
Among the various particles that may be produced in a nuclear reaction, α particles and protons are actually nuclei. α particles, also known as alpha particles, are high-energy helium nuclei consisting of two protons and two neutrons. Protons are the nuclei of hydrogen atoms.
In contrast, β particles or beta particles are high-speed electrons and are not nuclei. γ particles, gamma rays, are a form of very high-energy electromagnetic radiation and also not nuclei.