Every element is made up of an atom that contains a nucleus with positively charged protons and neural neurons. Surrounding the nucleus are orbitals that contain negatively charged electrons. Radiation occurs naturally when the nucleus is in an excited state. The excited state cannot be maintained and when the energy levels drop back to their ground state energy is released in the form of radiation. By definition, radiation is the disintegration of the nucleus.There are three types of radioactive decay particles. The alpha particle is the least dangerous. It is basically a helium nucleus. The beta particle is a high energy electron with a negative charge or positron with a positive charge. The beta particle is created with a neutron decay into a proton and an electron or when a proton decays into a neutron and a positron. Gamma radiation is the most dangerous form of radiation. It is a high energy electromagnetic wave. It is basically a photon that has no mass or charge. When excited electrons go back to their ground energy level they release gamma radiation.At first radioactive decay processes are random. The half life of a radioactive material is the time it takes for half of radioactive material to decay. Radioactive decay follows an exponential function. Different radioactive materials have different half lives and therefore different decay constants.