n. 1  The charter that King John of England issued in 1215 at the behest of his barons, recognizing the right of persons to certain basic liberties, such as due process, later also embodied in the American Constitution: We are heirs to a tradition given voice 800 years ago by Magna Carta, which ...
Radioactive decay occurs in unstable atomic nuclei â that is, ones that donât have enough binding energy to hold the nucleus together due to an excess of either protons or neutrons. It comes in three main types â named alpha, beta and gamma for the first three letters of the Greek alphabet.Alpha decay.fter a nucleus undergoes alpha or beta decay, it is often left in an excited state with excess energy. Just as an electron can move to a lower energy state by emitting a photon somewhere in the ultraviolet to infrared range, an atomic nucleus loses energy by emitting a gamma ray.
When an unstable nucleus of a radioactive isotope spontaneously  decays, the radioactive decay process is normally gamma radiation,  beta particle or alpha particle emission â¦ . During alpha emission, an  alpha particle or Helium-4 is released and the original isotope  becomes another isotope or element.