The Radioactive Decay Simulator emulates the radioactive decay of a group of like atoms. Users are able to select from a range of preset atoms, or enter the half-life of a specific atom that they wish to simulate. By adjusting the number of atoms, users are able to determine how even with a large number of atoms, the randomness of radioactive decay can be modeled. Users are able to observe the both number of decayed atoms as well as the number of non-decayed atoms remaining in a real time graph. The simulator can be sped up to allow atoms with a longer half-life to be analyzed quickly.