A simple test to determine the type of radioactive decay—alpha, beta, or gamma—typically involves using a Geiger counter along with different stopping media. Alpha particles can be stopped by a few centimeters of air or paper, beta particles require aluminum, and gamma rays penetrate most materials but can be blocked by lead. While a Geiger counter is the most straightforward tool for detection, other methods exist, such as using modified cameras or magnetic fields to observe particle deflection. However, any effective test necessitates some form of radiation detection. Ultimately, a Geiger counter remains the easiest and most reliable option for identifying radioactive decay types.