Respuesta :
The phrases that describe radioactive elements are;
-occur in nature
-decay at a constant rate
- have a half-life that determines their rate of decay
Radioactive elements are elements whose nucleus are liable to decay overtime followed by the release of energy (alpha particles, beta particles, or gamma rays) and conversion to different elements. Every element that has atomic number greater than 83 is radioactive. Most radioactive elements occur in nature. Examples include uranium, radium and thorium. Radioactive elements have a half-life that determines their rate of decay