Which are the three types of radiation?

• A. Alpha particle, Beta particle, and Gamma radiation
• B. Alpha particle, Gamma radiation only
• C. Beta particle and Gamma radiation
• D. X-ray, Alpha, and Gamma radiation

Answer: (A)

Three basic forms of radiation produced by radioactive decay are alpha particles, beta particles, and gamma radiation. An alpha particle is a heavy, positively charged helium nucleus with high ionizing power but very low penetration, so it can be stopped by a sheet of paper or the outer skin. A beta particle is a fast electron (or positron) with moderate penetration, typically blocked by a few millimeters of aluminum or plastic. Gamma radiation is high-energy electromagnetic radiation—photons with no mass or charge—offering deep penetration and requiring dense shielding like lead or thick concrete. Understanding these differences is crucial for selecting appropriate shielding and safety measures in any radiological environment.