The trace metals of Group 6, chromium (Cr), molybdenum (Mo), and tungsten (W), have strong lithophilic tendencies. They have variable oxidation states, possess bimodal redox behavior in terrestrial and aquatic environments, and are likely to be present in two oxidation states, +3 and +6 (Table 11.1). Metals of this group have the propensity to form oxyanions and coordinate only weakly with other common environmental ligands such as Cl− or OH−.