What is Radioactivity? Md. Saifur Rahman The phenomenon of emission of radioactive rays or particles from an element is called radioactivity. Radioactive elements emit three energetic rays, namely alpha, beta, and gamma.You may likeDo I need car insurance?What is car insurance?How could I get cheaper car insurance?What is auto insurance?Why Adulterant food is the barrier to sound health?What are the producers?What are food preservatives?What is food chain?What is tertiary consumer?