The process by which certain unstable elements spontaneously release radiation to transform into more stable elements; also called [[衰变|衰變|shuai1 bian4]] (shuāibiàn) or [[放射衰变|放射衰變|fang4 she4 shuai1 bian4]] (fàngshè shuāibiàn)

the process by which an unstable atomic nucleus loses energy by radiation

a graph showing how a radioactive substance breaks down over time

Heat produced by the radioactive decay of elements, especially in a nuclear reactor after it has been shut down

a series of radioactive decays of different radioactive decay products as a sequential series of transformations