Radioactive decay (also known as nuclear decay or radioactivity) is the process by which an unstable atomic nucleus loses energy (in terms of mass in its rest frame) by emitting radiation, such as an alpha particle, beta particle with neutrino or only a neutrino in the case of electron capture, gamma ray, or electron in the case of internal. Radioactive Dating. Because the radioactive half-life of a given radioisotope is not affected by temperature, physical or chemical state, or any other influence of the environment outside the nucleus save direct particle interactions with the nucleus, then radioactive samples continue to decay at a predictable rate and can be used as a clock. Radiometric dating is a means of determining the "age" of a mineral specimen by At the end of the first half life, only half of the radioactive element. Radioactive Dating and Half-Life with animation On the other side of the coin, is biological half-life, which is anapproximation of how long it takes for one half of an ingestedmaterial not necessarily radioactive to leave the body. The original term, half-life perioddating to Ernest Rutherford 's discovery of the principle inwas radioactive dating half life to half-life in the early s. The previous equation cannot be applied to the decay chain, but can be generalized as follows. Carbon 14 is used in Carbon dating. At first, it seemed as though the new radiation was similar to the then recently discovered X-rays. The difference between the mass of an atom and the sum of the masses radioactive dating half life its protons, neutrons, and electrons is called the mass defect. The most common isotopes used are Rubidium: