What defines radioactive material?

The characteristic that defines radioactive material is that it contains decaying atoms. Radioactive materials are those substances that emit radiation as a result of the decay of unstable isotopes. This decay process can produce alpha particles, beta particles, or gamma rays, which are forms of radiation. The presence of these decaying atoms is what makes a material classified as radioactive, influencing its behavior and the safety precautions needed when handling it. Understanding this definition is crucial for ensuring safety in environments where radioactive materials are present, such as in medical applications, nuclear power generation, and various scientific research fields.