Radioactive Decay - Wikipedia - alpha particle  ## Metadata - Author: **alpha particle** - Full Title: Radioactive Decay - Wikipedia - Category: #articles - URL: https://en.wikipedia.org/wiki/Radioactive_decay ## Highlights - Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered radioactive. Three of the most common types of decay are alpha decay (α-decay), beta decay (β-decay), and gamma decay (γ-decay), all of which involve emitting one or more particles