To use electron affinities properly, it is essential to keep track of sign. For any reaction that "releases" energy, the "change" Δ"E" in total energy has a negative value and the reaction is called an exothermic process. Electron capture for almost all non-noble gas atoms involves the release of energy and thus are exothermic. The positive values that are listed in tables of "E"ea are amounts or magnitudes. It is the word "released" within the definition "energy released" that supplies the negative sign to Δ"E". Confusion arises in mistaking "E"ea for a change in energy, Δ"E", in which case the positive values listed in tables would be for an endo- not exo-thermic process. The relation between the two is "E"ea = −Δ"E"(attach).