This experiment will use a technique known as neutron activation analysis (NAA) to determine the half-lives of two unusual isotopes, 28Al and 20F. The only stable isotopes of these elements are 27Al and 19F. Trace amounts of 26Al and 18F occur naturally, but the isotopes we will generate today are even more unstable and have no significant natural abundance. To produce these very unstable isotopes in measureable concentration, samples containing Al and F are placed next to a source of energetic neutrons. A number of neutron sources can be used; in this lab the samples are placed inside an operating nuclear reactor that emits energetic neutrons. This source has the advantage of a high neutron output that creates the desired isotopes rapidly and at higher concentrations, but it is only feasible for researchers that have access to nuclear reactors. At Oregon State University, the campus TRIGA reactor is set up for NAA experiments. How many neutrons are present in the nucleus of a 20F isotope?