Answer:
Radioactive decay: is the process by which an unstable atomic nucleus loses energy by radiation.
Half-life: in radioactivity, the interval of time required for one-half of the atomic nuclei of a radioactive sample to decay (change spontaneously into other nuclear species by emitting particles and energy), or, equivalently, the time interval required for the number of disintegrations per second of a radioactive material to decrease by one-half.
Radiometric dating: is a method used to date rocks and other objects based on the known decay rate of radioactive isotopes.
