^{4}\textrm{He}\) When a radioactive atom emits an alpha particle the mass number decreases by four and the atomic number drops by two. Here is the equation for the alpha decay of radon-219 into ...

Radioactive decay: Scientists use the half-life formula to describe the decay process of radioactive isotopes. It helps determine the rate of decay and predict how much of a substance will remain ...

Radioactive decay is a spontaneous and random process. A block of radioactive material will contain many trillions of nuclei and not all nuclei are likely to decay at the same time so it is ...