What defines radioactive material?

Radioactive material is defined as material that contains unstable atoms. These unstable atoms undergo radioactive decay, a process in which they emit radiation in the form of particles or electromagnetic waves. This decay occurs because the nucleus of the atom is unstable, leading it to transform into a more stable configuration.

The presence of unstable atoms is what distinguishes radioactive materials from non-radioactive materials, which consist of stable atoms that do not emit radiation. Understanding the nature of radioactive materials is essential for safety and handling protocols in radiological work, as the emitted radiation can pose health risks.

In contrast, materials containing stable atoms do not exhibit any radioactive behavior, materials that emit light may refer to luminescence and not specifically to radioactivity, and materials with no charge do not relate directly to radioactivity either, as both charged and neutral atoms can include stable or unstable isotopes.