The transition of a nucleus from one energy state to a lower one, usually involving the emission of a photon, electron, neutron, or alpha particle.
disintegration of the nucleus of an unstable atom by the release of radiation.
The spontaneous transformation of one nuclide into a different nuclide or into a different energy state of the same nuclide. The process results in the emission of nuclear radiation (alpha, beta, or gamma radiation).
The nuclear transformation of a parent nucleus resulting in a daughter nucleus. During this process, the emission of particles and/or electromagnetic energy can occur. This is also called a disintegration.
The spontaneous change of an unstable nucleaus with the simultaneous emission of energy in the form of alpha or beta particles and/or gamma rays.
The decrease in the amount of any radioactive material with the passage of time, due to the spontaneous emission from the atomic nuclei of either alpha or beta particles, often accompanied by gamma radiation.
Disintegration of the nucleus of an unstable nuclide by the spontaneous emission of charged particles and/or photons.