Radioactivity — Science definition
The spontaneous emission of particles or energy from an unstable atomic nucleus.
Where it is taught
- Nuclear Chemistry — Redox, Cells & Nuclear Chemistry, Physical Science: Chemistry, Grade 11
In use
Some nuclei are unstable — they hold a combination of protons and neutrons that simply cannot last — and to reach a more stable form they spontaneously fling out particles or energy, a behavior called radioactivity.
Nuclear Chemistry