
Radioactive decay - Wikipedia
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.
Radioactivity | Definition, Types, Applications, & Facts | Britannica
4 days ago · Radioactivity, property exhibited by certain types of matter of emitting energy and subatomic particles spontaneously. It is, in essence, an attribute of individual atomic nuclei.
The Radioactive Atom: An Overview | Radiation and Your Health | CDC
Feb 22, 2024 · This process is known as radioactivity and the energy that's released is radiation. After an atom expels energy from the nucleus, the composition of the nucleus changes, and we are left …
Radioactivity: Definition, Types, Formula, and Applications
Jun 10, 2025 · Radioactivity occurs when an atom has an excess of energy, mass, or both, making its nucleus unstable. To reach a lower, more stable energy level, it releases energy in the form of …
Radioactivity and the Types of Radioactive Decay
May 30, 2021 · Radioactivity is the spontaneous emission of ionizing radiation from nuclear decay and reactions. The three main types of radioactive decay are alpha, beta, and gamma decay, but there …
Radiation Basics | US EPA
Mar 24, 2026 · Radiation can come from unstable atoms or it can be produced by machines. There are two kinds of radiation; ionizing and non-ionizing radiation. Learn about alpha, beta, gamma and x-ray …
What Is Radioactivity? - Energy.gov
As its name implies, radioactivity is the act of emitting radiation spontaneously. This is done by an atomic nucleus that, for some reason, is unstable; it "wants" to give up some energy in order to shift …
Radiation in Everyday Life - International Atomic Energy Agency
Radioactivity is the term used to describe disintegration of atoms. The atom can be characterized by the number of protons in the nucleus. Some natural elements are unstable. Therefore, their nuclei …
Radiation Basics | Nuclear Regulatory Commission - NRC
These forces within the atom work toward a strong, stable balance by getting rid of excess atomic energy (radioactivity). In that process, unstable nuclei may emit a quantity of energy, and this …
Radioactivity | Understanding Its Basics & Effects
May 29, 2024 · Radioactivity is a natural phenomenon involving the decay of unstable atomic nuclei, which release energy in the form of radiation. This process helps us understand atomic structures …