Q. What is artificial radioactivity?
The phenomenon by which still light elements are made radioactive by artificial or induced methods is called artificial radioactivity.
α-decay When a radioactive nucleus disintegrates by release an α-particle the atomic number decreases by two and mass number decreases by four.
Instance Radium (88Ra226) is converted to radon (86Rn222) due to α-decay
88Ra226 → 86Rn222 + 2He4