 Elements 165 and 166 should normally exhibit the +1 and +2 oxidation states respectively, although the ionization energies of the 7d electrons are low enough to allow higher oxidation states like +3 for element 165.The oxidation state +4 for element 166 is less likely, creating a situation similar to the lighter elements in groups 11 and 12 (particularly gold and mercury).As with mercury but not copernicium, ionization of element 166 to Uhh2+ is expected to result in a 7d10 configuration corresponding to the loss of the s-electrons but not the d-electrons, making it more analogous to the lighter "less relativistic" group 12 elements zinc, cadmium, and mercury, which have essentially no transition-metal character.