Radioactive decay (which is also called radioactivity, nuclear disintegration, radioactive disintegration, and nuclear decay), is a process in which unstable atomic nuclei lose their energy via the process of radiation. These nuclei can emit alpha particles, neutrinos, beta particles, etc. Any material whose atomic nucleus is unstable and is capable of undergoing radioactive decay can be called a radioactive material. It is important to note that the process of radioactive decay is stochastic (random) and the process proceeds at the atomic level. As per the quantum theory, it is not possible to predict whether a given atom will undergo radioactive decay or nuclear disintegration. Common examples of radioactive decay include alpha decay, proton emission, double proton emission, beta decay, electron capture, and neutron emission.