Radioactive decay

Radioactive decay is the process by which radionuclides decay, emitting ionising radiation.

The observed forms of decay are alpha decay, beta decay, neutron emission, proton emission, and spontaneous fission. Of these, only alpha and beta decay are common in nature or in the decay chains of radioactive waste.

Neutron emission is also important as the most important reason for the difficulty of manufacturing a nuclear bomb from lower grades of plutonium.

Many radionuclides have several different modes of decay, each with its own probability. Bismuth-212, for example, has three.

All radioactive decay is also associated with emission of gamma radiation in varying degrees.

Nearly all decay products are themselves radioactive, giving rise to decay chains which eventually end in a stable nuclide.