ABSTRACT
In the oxygen and fluorine Groups the position is more complicated because of the wider ranges of oxidation states. Oxygen and the halogens are most stable in the negative states. The VI state is stable for sulfur and falls in stability for the heavier elements of the oxygen Group, but both the IV and the II states are relatively stable for the heavy elements. Among the halogens, chlorine and iodine both show the Group state of VII in oxyions; bromine (VII) was only recently found. Iodine is also fairly stable in the V and III states. Thus, the general trend for the lower oxidation states to be more stable for the heavier elements is shown by elements such as iodine or tellurium, but more than one state is involved and no simple rule may be given. Of the rare gas compounds, the difluorides are known to exist for radon and krypton as well as for xenon. The other oxidation states in Table 17.1 are shown by xenon.
