S: (n) decay, radioactive decay, disintegration (the spontaneous disintegration of a radioactive substance along with the emission of ionizing radiation)
W: (v) disintegrate [Related to: disintegration] (lose a stored charge, magnetic flux, or current) "the particles disintegrated during the nuclear fission process"
S: (n) annihilation, disintegration (total destruction) "bomb tests resulted in the annihilation of the atoll"