Question

what is meant by radioactivity and radioactive element?

Answer 1

radioactive element. an element subject to spontaneous degeneration of its nucleus accompanied by the emission of alpha particles, beta particles, or gamma rays. All elements with atomic numbers greater than 83 are radioactive. Naturally occurring radioactive elements include radium, thorium, and uranium.

Answer 2

Radioactivity is the spontaneous emission of radiation in the form of particles or high energy photons resulting from a nuclear reaction