The first four ionization energies for an imaginary element, Xz are E1 = 102 kcal, E2 = 186 kcal, E3 = 4,021 kcal, and E4 = 4,862 kcal. The number of valence electrons most probable as indicated by this ionization data is:

How is electrolysis most commonly used to produce an energy source? a - splitting water molecules produces oxygen, which organisms breathe to fuel their bodies. b - splitting water molecules produces hydrogen gas, which is used to power machines through hydrogen fuel cells. c - splitting carbon dioxide molecules produces coal, a form of carbon that can be burned to produce heat. d - splitting carbon dioxide molecules produces natural gas, which can be burned to generate electricity in power plants.