Californium oxide fluoride

Its stability then decreases progressively until we reach curium where aqueous solutions containing the tetra-positive state must be complexed by ligands such as fluoride or phosphotungstate. Even then, they oxidize water and revert to cur-ium(lll). The expected drop in I4 between curium and berkelium provides Bk" (aq) with a stability similar to that of Ce (aq), but the decrease in stability is then renewed, and beyond californium, the +4 oxidation state has not yet been prepared [2, 10, 15]. 

The actinides offer a greater range of oxidation states in their fluorides than do the lanthanides, particularly in the first half of the series. The oxidation states of the actinide fluorides are shovm in Table 7.3. The pattern of stable oxidation states is very much like those of the transition elements rather than like the lanthanides, but towards the half-full 5f orbitals stage and beyond the actinides tend to mirror the lanthanides. The trans-californium elements are not included in Table 7.3. They are more lanthanide-like and form only +3 fluorides. 

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