Which radiation is a high-energy wave emitted from an unstable nucleus and does not consist of particles?

• A. Gamma Radiation
• B. Alpha Radiation
• C. Beta Radiation
• D. Neutron Radiation

Answer: (A)

Gamma radiation is electromagnetic radiation released when a nucleus relaxes from an excited state after other decays. It carries energy as photons and has no rest mass or electric charge, so it isn’t a material particle being emitted. The nucleus doesn’t change its number of protons or neutrons—just sheds excess energy to reach a lower energy state. In contrast, alpha radiation is a heavy helium nucleus emitted, beta radiation involves electrons or positrons, and neutron radiation is a free neutron; all of these are particulate emissions with mass. So gamma radiation best fits the idea of a high-energy wave emitted from a nucleus without a particulate emission.