activity (radioactivity)

Radioactivity is the process where unstable atoms release energy by emitting particles or waves, such as alpha, beta, or gamma rays, to become more stable. These natural or man-made changes occur spontaneously and over time, transforming the atom into a different element or isotope. This emission can be detected and measured, and it’s important in fields like medicine, energy, and scientific research. Radioactivity is a random event at the atomic level, but the rate at which it occurs can be predictable for a specific substance, described by its half-life—the time needed for half of the radioactive atoms to decay.